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Housing and Urban Development
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2018-04-01
2018-04-01
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MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS
3280

PART 3280
Housing and Urban Development
Regulations Relating to Housing and Urban Development (Continued)
OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT
Pt. 3280

PART 3280—MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS

Subpart A—General
Sec.
3280.1
Scope.
3280.2
Definitions.
3280.3
Manufactured home procedural and enforcement regulations and consumer manual requirements.
3280.4
Incorporation by reference.
3280.5
Data plate.
3280.6
Serial number.
3280.7
Excluded structures.
3280.8
Waivers.
3280.9
Interpretative bulletins.
3280.10
Use of alternative construction.
3280.11
Certification label.

Subpart B—Planning Considerations
3280.101
Scope.
3280.102
Definitions.
3280.103
Light and ventilation.
3280.104
Ceiling heights.
3280.105
Exit facilities; exterior doors.
3280.106
Exit facilities; egress windows and devices.
3280.107
Interior privacy.
3280.108
Interior passage.
3280.109
Room requirements.
3280.110
Minimum room dimensions.
3280.111
Toilet compartments.
3280.112
Hallways.
3280.113
Glass and glazed openings.

Subpart C—Fire Safety
3280.201
Scope.
3280.202
Definitions.
3280.203
Flame spread limitations and fire protection requirements.
3280.204
Kitchen cabinet protection.
3280.205
Carpeting.
3280.206
Firestopping.
3280.207
Requirements for thermal insulating materials.
3280.208
Requirements for foam plastic thermal insulating materials.
3280.209
Smoke alarm requirements.
3280.210
Fire testing.

Subpart D—Body and Frame Construction Requirements
3280.301
Scope.
3280.302
Definitions.
3280.303
General requirements.
3280.304
Materials.
3280.305
Structural design requirements.
3280.306
Windstorm protection.
3280.307
Resistance to elements and use.
3280.308
Formaldehyde emission controls for certain wood products.
3280.309
Health Notice on formaldehyde emissions.

Subpart E—Testing
3280.401
Structural load tests.
3280.402
Test procedures for roof trusses.
3280.403
Requirements for windows, sliding glass doors, and skylights.
3280.404
Standard for egress windows and devices for use in manufactured homes.
3280.405
Standard for swinging exterior passage doors for use in manufactured homes.
3280.406
Air chamber test method for certification and qualification of formaldehyde emission levels.

Subpart F—Thermal Protection
3280.501
Scope.
3280.502
Definitions.
3280.503
Materials.
3280.504
Condensation control and installation of vapor retarders.
3280.505
Air infiltration.
3280.506
Heat loss/heat gain.
3280.507
Comfort heat gain.
3280.508
Heat loss, heat gain and cooling load calculations.
3280.509
Criteria in absence of specific data.
3280.510
Heat loss certificate.
3280.511
Comfort cooling certificate and information.

Subpart G—Plumbing Systems
3280.601
Scope.
3280.602
Definitions.
3280.603
General requirements.
3280.604
Materials.
3280.605
Joints and connections.
3280.606
Traps and cleanouts.
3280.607
Plumbing fixtures.
3280.608
Hangers and supports.
3280.609
Water distribution systems.
3280.610
Drainage systems.
3280.611
Vents and venting.
3280.612
Tests and inspection.

Subpart H—Heating, Cooling and Fuel Burning Systems
3280.701
Scope.
3280.702
Definitions.
3280.703
Minimum standards.
3280.704
[Reserved]
3280.705
Gas piping systems.
3280.706
Oil piping systems.
3280.707
Heat producing appliances.
3280.708
Exhaust duct system and provisions for the future installation of a clothes dryer.
3280.709
Installation of appliances.
3280.710
Venting, ventilation and combustion air.
3280.711
Instructions.
3280.712
Marking.
3280.713
Accessibility.
3280.714
Appliances, cooling.
3280.715
Circulating air systems.

Subpart I—Electrical Systems
3280.801
Scope.
3280.802
Definitions.
3280.803
Power supply.
3280.804
Disconnecting means and branch-circuit protective equipment.
3280.805
Branch circuits required.
3280.806
Receptacle outlets.
3280.807
Fixtures and appliances.
3280.808
Wiring methods and materials.
3280.809
Grounding.
3280.810
Electrical testing.
3280.811
Calculations.
3280.812
Wiring of expandable units and dual units.
3280.813
Outdoor outlets, fixtures, air conditioning equipment, etc.
3280.814
Painting of wiring.
3280.815
Polarization.
3280.816
Examination of equipment for safety.

Subpart J—Transportation
3280.901
Scope.
3280.902
Definitions.
3280.903
General requirements for designing the structure to withstand transportation shock and vibration.
3280.904
Specific requirements for designing the transportation system.

Authority:
42 U.S.C. 3535(d), 5403, and 5424.

Source:
40 FR 58752, Dec. 18, 1975, unless otherwise noted. Redesignated at 44 FR 20679, Apr. 6, 1979.

Subpart A—General
§ 3280.1
Scope.
This standard covers all equipment and installations in the design, construction, transportation, fire safety, plumbing, heat-producing and electrical systems of manufactured homes which are designed to be used as dwelling units. This standard seeks to the maximum extent possible to establish performance requirements. In certain instances, however, the use of specific requirements is necessary.
[58 FR 55002, Oct. 25, 1993]
§ 3280.2
Definitions.
Definitions in this subpart are those common to all subparts of the standard and are in addition to the definitions provided in individual parts. The definitions are as follows:
Approved, when used in connection with any material, appliance or construction, means complying with the requirements of the Department of Housing and Urban Development.
Bay window—a window assembly whose maximum horizontal projection is not more than two feet from the plane of an exterior wall and is elevated above the floor level of the home.
Certification label means the approved form of certification by the manufacturer that, under § 3280.8, is permanently affixed to each transportable section of each manufactured home manufactured for sale in the United States.
Dwelling unit means one or more habitable rooms which are designed to be occupied by one family with facilities for living, sleeping, cooking and eating.
Equipment includes materials, appliances, devices, fixtures, fittings or accessories both in the construction of, and in the fire safety, plumbing, heat-producing and electrical systems of manufactured homes.
Federal manufactured home construction and safety standard means a reasonable standard for the construction, design, and performance of a manufactured home which meets the needs of the public including the need for quality, durability, and safety.
Installations means all arrangements and methods of construction, as well as fire safety, plumbing, heat-producing and electrical systems used in manufactured homes.
Labeled means a label, symbol or other identifying mark of a nationally recognized testing laboratory, inspection agency, or other organization concerned with product evaluation that maintains periodic inspection of production of labeled equipment or materials, and by whose labeling is indicated compliance with nationally recognized standards or tests to determine suitable usage in a specified manner.
Length of a manufactured home means its largest overall length in the traveling mode, including cabinets and other projections which contain interior space. Length does not include bay windows, roof projections, overhangs, or eaves under which there is no interior space, nor does it include drawbars, couplings or hitches.
Listed or certified means included in a list published by a nationally recognized testing laboratory, inspection agency, or other organization concerned with product evaluation that maintains periodic inspection of production of listed equipment or materials, and whose listing states either that the equipment or material meets nationally recognized standards or has been tested and found suitable for use in a specified manner.
Manufacturer means any person engaged in manufacturing or assembling manufactured homes, including any person engaged in importing manufactured homes for resale.
Manufactured home means a structure, transportable in one or more sections, which in the traveling mode is 8 body feet or more in width or 40 body feet or more in length or which when erected on-site is 320 or more square feet, and which is built on a permanent chassis and designed to be used as a dwelling with or without a permanent foundation when connected to the required utilities, and includes the plumbing, heating, air-conditioning, and electrical systems contained in the structure. This term includes all structures that meet the above requirements except the size requirements and with respect to which the manufacturer voluntarily files a certification pursuant to § 3282.13 of this chapter and complies with the construction and safety standards set forth in this part 3280. The term does not include any self-propelled recreational vehicle. Calculations used to determine the number of square feet in a structure will include the total of square feet for each transportable section comprising the completed structure and will be based on the structure's exterior dimensions measured at the largest horizontal projections when erected on site. These dimensions will include all expandable rooms, cabinets, and other projections containing interior space, but do not include bay windows. Nothing in this definition should be interpreted to mean that a manufactured home necessarily meets the requirements of HUD's Minimum Property Standards (HUD Handbook 4900.1) or that it is automatically eligible for financing under 12 U.S.C. 1709(b).
Manufactured home construction means all activities relating to the assembly and manufacture of a manufactured home including, but not limited to, those relating to durability, quality and safety.
Manufactured home safety means the performance of a manufactured home in such a manner that the public is protected against any unreasonable risk of the occurrence of accidents due to the design or construction of such manufactured home, or any unreasonable risk of death or injury to the user or to the public if such accidents do occur.
Registered Engineer or Architect means a person licensed to practice engineering or architecture in a state and subject to all laws and limitations imposed by the state's Board of Engineering and Architecture Examiners and who is engaged in the professional practice of rendering service or creative work requiring education, training and experience in engineering sciences and the application of special knowledge of the mathematical, physical and engineering sciences in such professional or creative work as consultation, investigation, evaluation, planning or design and supervision of construction for the purpose of securing compliance with specifications and design for any such work.
Secretary means the Secretary of Housing and Urban Development, or an official of the Department delegated the authority of the Secretary with respect to title VI of Pub. L. 93-383.
State includes each of the several States, the District of Columbia, the Commonwealth of Puerto Rico, Guam, the Virgin Islands, the Canal Zone, and American Samoa.
Width of a manufactured home means its largest overall width in the traveling mode, including cabinets and other projections which contain interior space. Width does not include bay windows, roof projections, overhangs, or eaves under which there is no interior space.
[40 FR 58752, Dec. 18, 1975, as amended at 42 FR 960, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 47 FR 28092, June 29, 1982; 58 FR 55002, Oct. 25, 1993; 61 FR 5216, Feb. 9, 1996; 72 FR 27228, May 14, 2007]
§ 3280.3
Manufactured home procedural and enforcement regulations and consumer manual requirements.
A manufacturer must comply with the requirements of this part 3280, part 3282 of this chapter, and 42 U.S.C. 5416.
[61 FR 18250, Apr. 25, 1996]
§ 3280.4
Incorporation by reference.
(a) The specifications, standards, and codes of the following organizations are incorporated by reference in 24 CFR part 3280 (this Standard) pursuant to 5 U.S.C. 552(a) and 1 CFR part 51 as though set forth in full. The incorporation by reference of these standards has been approved by the Director of the Federal Register. Incorporated standards have the same force and effect as this Standard (24 CFR part 3280), except that whenever reference standards and this Standard are inconsistent, the requirements of this Standard prevail to the extent of the inconsistency. The Department will enforce the listed editions of material incorporated by this section. Where two or more incorporated standards are equivalent in application, the manufacturer may use either standard. If a later edition is to be enforced, the Department will publish a notice of change in the Federal Register. These incorporated standards are available for purchase from the organization that developed the standard at the corresponding addresses noted below. Incorporated standards are available for inspection at the Office of Manufactured Housing Program, Manufactured Housing and Construction Standards Division, U.S. Department of Housing and Urban Development, 451 Seventh Street SW., Room B-133, Washington, DC 20410. Copies of incorporated standards that are not available from their producer organizations may be obtained from the Office of Manufactured Housing Programs. These standards are also available for inspection at the National Archives and Records Administration (NARA). For more information on the availability of this material at NARA, call 202-741-6030 or go to http://www.archives.gov/federal_register.
(b) Air Conditioning & Refrigeration Institute (ARI), 4100 North Fairfax Drive, Suite 200, Arlington, VA 22203, telephone number 703-524-8800, fax number 703-528-3816, Web site: http://www.lightindustries.com/ARI/.
(1) ANSI/ARI Standard 210/240-89, Unitary Air-Conditioning and Air-Source Heat Pump Equipment, IBR approved for §§ 3280.511(b), 3280.703, and 3280.714(a),
(2) [Reserved]
(c) Aluminum Association (AA), 1525 Wilson Blvd., Suite 600, Arlington, VA 22209; telephone number 703-358-2960, fax number 703-358-3921; Web site: http://www.aluminum.org.
(1) Aluminum Design Manual, Specifications and Guidelines for Aluminum Structures, Part 1-A, Sixth Edition, October 1994, IBR approved for § 3280.304(b).
(2) Aluminum Design Manual, Specifications and Guidelines for Aluminum Structures, Part 1-B, First Edition, October 1994, IBR approved for § 3280.304(b).
(d) American Architectural Manufacturers Association (AAMA), 1827 Walden Office Square, Suite 550, Schaumburg, IL 60173, telephone number 847-303-5664, fax number 847-303-5774, Web site: http://www.aamanet.org.
(1) AAMA 1503.1-88, Voluntary Test Method for Thermal Transmittance and Condensation Resistance of Windows, Doors, and Glazed Wall Sections, IBR approved for § 3280.508(e).
(2) AAMA 1600/I.S.7-00, Voluntary Specification for Skylights, 2003 IBR approved for § 3280.305(c).
(3) AAMA 1701.2-95, Voluntary Standard Primary Window and Sliding Glass Door for Utilization in Manufactured Housing, IBR approved for §§ 3280.403(e) and 3280.404(b).
(4) AAMA 1702.2-95, Voluntary Standard Swinging Exterior Passage Door for Utilization in Manufactured Housing, IBR approved for § 3280.405(b) and (e).
(5) AAMA Standard 1704-1985, Voluntary Standard Egress Window Systems for Utilization in Manufactured Housing, IBR approved for § 3280.404(b).
(6) AAMA/WDMA/CSA/101/I.S.2/A440-08 North American Fenestration Standard/Specification for Windows, Doors and Skylights, January 2008, IBR approved for § 3280.403(b) and (e).
(7) ANSI/AAMA/NWWDA 101/I.S.2-97,Voluntary Specifications for Aluminum, Vinyl (PVC) and Wood Windows and Glass Doors, IBR approved for § 3280.304(b).
(e) American Forest and Paper Association (AFPA), 1111 Nineteenth Street, Suite 800, Washington, DC 20036 (previously named National Forest Products Association (NFPA), telephone number 1-800-878-8878, Web site: http://www.afandpa.org.
(1) AFPA, Design Values for Joists and Rafters 1992, IBR approved for § 3280.304(b).
(2) AFPA PS-20-70, Span Tables for Joists and Rafters, 1993, IBR approved for § 3280.304(b).
(3) ANSI/AFPA NDS-2001, National Design Specifications for Wood Construction, 2001 Edition, with Supplement, Design Values for Wood Construction, November 30, 2001, IBR approved for § 3280.304(b).
(4) AFPA, Wood Structural Design Data, 1986 Edition with 1992 Revisions, IBR approved for § 3280.304(b).
(f) American Gas Association (AGA), 400 North Capitol Street NW., Washington, DC 20001, telephone number 202-824-7000, Web site: http://www.aga.org/Pages/default.aspx.
(1) AGA No. 3-87, Requirements for Gas Connectors for Connection of Fixed Appliances for Outdoor Installation, Park Trailers, and Manufactured (Mobile) Homes to the Gas Supply, IBR approved for § 3280.703.
(2) [Reserved]
(g) American Hardboard Association (AHA), 1210 West NW Highway, Palatine, IL 60067, Web site: http://hardboard.org.
(1) ANSI/AHA A135.4-1995, Basic Hardboard, IBR approved for § 3280.304(b).
(2) ANSI/AHA A135.5-1995, Prefinished Hardboard Paneling, IBR approved for § 3280.304(b).
(3) ANSI/AHA A135.6-1998, Hardboard Siding, IBR approved for § 3280.304(b).
(h) American Institute of Steel Construction (AISC), One East Wacker Drive, Chicago, IL 60601, telephone number 312-670-2400, fax number 312-670-5403, Web site: http://www.aisc.org/.
(1) AISC-S335, 1989. Specification for Structural Steel Buildings—Allowable Stress Design and Plastic Design (except for the following parts of this standard which are not incorporated by reference: 1.3.3, 1.3.4, 1.3.5, 1.3.6, 1.4.6, 1.5.1.5, 1.5.5, 1.6, 1.7, 1.8, 1.9, 1.10.4 through 1.10.7, 1.10.9, 1.11, 1.13, 1.14.5, 1.17.7 through 1.17.9, 1.19.1, 1.19.3, 1.20, 1.21, 1.23.7, 1.24, 1.25.1 through 1.25.5, 1.26.4, 2.3, 2.4, 2.8 through 2.10), June 1, 1989, IBR approved for §§ 3280.304(b) and 3280.305(j).
(2) [Reserved]
(i) American Iron and Steel Institute (AISI), 25 Massachusetts Ave., NW., Suite 800, Washington, DC 20001, telephone number 202-452-7100, Web site: http://www.steel.org.
(1) AISI, Specification for the Design of Cold-Formed Steel Structural Members, 1996, IBR approved for §§ 3280.304(b) and 3280.305(j).
(2) [Reserved]
(j) American National Standards Institute (ANSI), 25 West 43rd Street, 4th floor, New York, NY 10018, telephone number 212-642-4900, fax number 212-398-0023, Web site: http://www.ansi.org.
(1) ANSI A112.14.1-1975, Backflow Valves, IBR approved for § 3280.604(b).
(2) ANSI A112.19.5-1979, Trim for Water Closet, Bowls, Tanks, and Urinals, IBR approved for § 3280.604(b).
(3) ANSI/AITC A190.1-1992, For wood products—Structural Glued Laminated Timber, IBR approved for § 3280.304(b).
(4) ANSI A208.1-1999, Particleboard, IBR approved for § 3280.304(b).
(5) ANSI A208.2-2002, Medium Density Fiberboard (MDF) For Interior Applications, approved May 13, 2002, IBR approved for § 3280.304(b).
(6) ANSI B16.18-1984, Cast Copper Alloy Solder-Joint Pressure Fittings, IBR approved for § 3280.604(b).
(7) ANSI C72.1-1972, section 4.3.1, Household Automatic Electric Storage Type Water Heaters, IBR approved for § 3280.707(d).
(8) ANSI/IAS LC 1-1997, Fuel Gas Piping Systems Using Corrugated Stainless Steel Tubing (CSST), approved October 28, 1996, IBR approved for § 3280.705(b).
(9) ANSI Z21.1-2000, Household Cooking Gas Appliances, IBR approved for § 3280.703.
(10) ANSI Z21.5.1-1999, Gas Clothes Dryers Volume 1, Type 1 Clothes Dryers, with Addendum Z21.5.1a-1999, IBR approved for § 3280.703.
(11) ANSI Z21.10.1-1998, Gas Water Heaters—Volume 1, Storage Water Heaters with Input Ratings of 75,000 BTU per hour or Less, with Addendum Z21.10.1a-2000, IBR approved for §§ 3280.703 and 3280.707(d).
(12) ANSI Z21.15-1997, Manually Operated Gas Valves for Appliances, Appliance Connector Valves and Hose End Valves, IBR approved for §§ 3280.703 and 3280.705(c).
(13) ANSI Z21.19-1990, with Addendum ANSI Z21.19a-1992 and Z21.19b-1995, Refrigerators Using Gas Fuel, IBR approved for § 3280.703.
(14) ANSI Z21.20 with Addendum Z21.20a-2000, Automatic Gas Ignition Systems and Components, IBR approved for § 3280.703.
(15) ANSI Z21.21-2000, Automatic Valves for Gas Appliances, IBR approved for § 3280.703.
(16) ANSI Z21.22-1999, Relief Valves for Hot Water Supply Systems, IBR approved for §§ 3280.604(b) and 3280.703.
(17) ANSI Z21.23-1993, Gas Appliance Thermostats, approved August 10, 1993, IBR approved for § 3280.703.
(18) ANSI Z21.24-1997/CGA 6.10-M97, Connectors for Gas Appliances, IBR approved for § 3280.703.
(19) ANSI Z21.40.1-1996/CGA 2.91-M96, Gas-Fired, Heat Activated Air Conditioning and Heat Pump Appliances, IBR approved for §§ 3280.703 and 3280.714(a).
(20) ANSI Z21.47-1990 with Addendum Z21.47a-1990 and Z21.47b-1992, Gas-Fired Central Furnaces (Except Direct Vent System Central Furnaces), IBR approved for § 3280.703.
(21) ANSI Z34.1-1993, Third-Party Certification Programs for Products, Processes, and Services, IBR approved for §§ 3280.403(e) and 3280.405(e).
(22) ANSI Z97.1-2004, Standard for Safety Glazing Materials used in Buildings—Safety Performance Specifications and Methods of Test, copyright 2004, IBR approved for §§ 3280.113(c), 3280.304(b), 3280.403(d)(1), 3280.604(b), and 3280.607(b).
(23) ANSI Z124.1-1987, Plastic Bathtub Units with Addendum Z124.1a-1990 and Z124.1b-1991, IBR approved for § 3280.604(b).
(24) ANSI Z124.2-1987, Plastic Shower Receptors and Shower Stalls with Addendum Z124.2a-1990, IBR approved for § 3280.604(b).
(25) ANSI Z124.3-1986, Plastic Lavatories with Addendum Z124.3a-1990, IBR approved for § 3280.604(b).
(26) ANSI Z124.4-1986, Plastic Water Closets, Bowls, and Tanks with Addenda Z124.4a-1990, IBR approved for § 3280.604(b).
(27) ANSI Z124.5-1997, Plastic Toilet (Water Closets) Seats, IBR approved for § 3280.604(b).
(28) ANSI Z124.7-1997, Prefabricated Plastic Spa Shells, IBR approved for § 3280.604(b).
(29) ANSI Z-124.9-1994, Plastic Urinal Fixtures, IBR approved for § 3280.604(b).
(k) The Engineered Wood Association (APA) (formerly the American Plywood Association), 7011 South 19th Street, Tacoma, WA 98411, telephone number 253-565-6600, fax number 253-565-7265, Web site: http://www.apawood.org.
(1) APA D410A-2004, Panel Design Specification, IBR approved for § 3280.304(b).
(2) APA E30P-1996, APA Design/Construction Guide, Residential and Commercial Structures, IBR approved for § 3280.304(b).
(3) APA E30R, Engineered Wood Construction Guide, revised January 2001, IBR approved for § 3280.304(b).
(4) APA H815E-1995 (PDS Supplement #5), Design and Fabrication of All-Plywood Beams, IBR approved for § 3280.304(b).
(5) APA S 811M-1990 (PDS Supplement 1), Design and Fabrication of Plywood Curved Panels, IBR approved for § 3280.304(b).
(6) APA S 812R, Design and Fabrication of Glued Plywood-Lumber Beams, revised November 1998, Supplement #2, July 1992 IBR approved for § 3280.304.
(7) APA U 813L, Design and Fabrication of Plywood Stressed-Skin Panels, revised April 1996, Supplement # 3, August 1992, IBR approved for § 3280.304(b).
(8) APA U 814H, Design and Fabrication of Plywood, Sandwiched Panels, revised September 1993, Supplement #4, March 1990, IBR approved for § 3280.304(b).
(l) American Society of Civil Engineers (ASCE), 1801 Alexander Bell Drive, Reston, VA 20191, telephone number 800-548-2723, Web site: http://www.asce.org.
(1) ANSI/ASCE 7-88, Minimum Design Loads for Buildings and Other Structures, IBR approved for §§ 3280.5(f), 3280.304(b), and 3280.305(c).
(2) SEI/ASCE 8-02, Specification for the Design of Cold-Formed Stainless Steel Structural Members, 2002, IBR approved for §§ 3280.304(b) and 3280.305(j).
(3) ASCE 19-96, Structural Applications of Steel Cables for Buildings, IBR approved for § 3280.304(b).
(m) American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE), 1791 Tullie Circle NE., Atlanta, GA 30329, telephone number 404-636-8400, fax number 404-321-5478, Web site: https://www.ashrae.org/home/.
(1) 1997 ASHRAE Handbook of Fundamentals, Inch-Pound Edition (1997), chapters 22 through 27, (except for the following parts of this standard that are not incorporated by reference: 23.1 Steel Frame Construction; 23.2 Masonry Construction; 23.3 Foundations and Floor Systems; 23.15 Pipes; 23.17 Tanks, Vessels, and Equipment; 23.18 Refrigerated Rooms and Buildings; 24.18 Mechanical and Industrial Systems; 25.19 Commercial Building Envelope Leakage; 27.9 Calculation of Heat Loss from Crawl Spaces). IBR approved for §§ 3280.508(a), 3280.508(e), and 3280.511(a).
(2) [Reserved]
(n) ASME (formally the American Society of Mechanical Engineers), Two Park Avenue, New York, NY 10016-5990, telephone number 800-843-2763, Web site: http://www.asme.org/.
(1) ASME A112.1.2-1991, Air Gaps in Plumbing Systems, IBR approved for § 3280.604(b).
(2) ANSI/ASME A112.4.1-1993, Water Heater Relief Valve Drain Tubes, IBR approved for § 3280.604(b).
(3) ANSI/ASME A112.4.3-1999, Plastic Fittings for Connecting Water Closets to the Sanitary Drainage System, IBR approved for § 3280.604(b).
(4) ASME/ANSI A112.18.1M-1989, Plumbing Fixture Fittings, IBR approved for § 3280.604(b).
(5) ASME A112.18.3M-1996, Performance Requirements for Backflow Protection Devices and Systems in Plumbing Fixture Fittings, IBR approved for § 3280.604(b).
(6) ASME A112.18.6-1999, Flexible Water Connectors, IBR approved for § 3280.604(b).
(7) ASME A112.18.7-1999, Deck Mounted Bath/Shower Transfer Valves with Integral Backflow Protection, IBR approved for § 3280.604(b).
(8) ANSI/ASME A112.19.1M-1987, Enameled Cast Iron Plumbing Fixtures, IBR approved for § 3280.604(b).
(9) ANSI/ASME A112.19.2(M)-1990, Vitreous China Plumbing Fixtures, IBR approved for § 3280.604(b).
(10) ANSI/ASME A112.19.3M-1987, Stainless Steel Plumbing Fixtures (Designed for Residential Use), IBR approved for § 3280.604(b).
(11) ANSI/ASME A112.19.4(M)-1984, Porcelain Enameled Formed Steel Plumbing Fixtures, IBR approved for § 3280.604(b).
(12) ASME A112.19.6-1995, Hydraulic Performance Requirements for Water Closets and Urinals, IBR approved for § 3280.604(b).
(13) ASME/ANSI A112.19.7M-1987, Whirlpool Bathtub Appliances, IBR approved for § 3280.604(b).
(14) ASME/ANSI A112.19.8M-1989, Suction Fittings for Use in Swimming Pools, Wading Pools, Spas, Hot Tubs, and Whirlpool Bathtub Appliances, IBR approved for § 3280.604(b).
(15) ASME A112.19.9M-1991, Non-Vitreous Ceramic Plumbing Fixtures, IBR approved for § 3280.604(b).
(16) ASME A112.19.10-1994, Dual Flush Devices for Water Closets, IBR approved for § 3280.604(b).
(17) ANSI/ASME A112.21.3M-1985, Hydrants for Utility and Maintenance Use, IBR approved for § 3280.604(b).
(18) ANSI/ASME B1.20.1-1983, Pipe Threads, General Purpose (Inch), IBR approved for §§ 3280.604(b), 3280.703, 3280.705(e), and 3280.706(d).
(19) ANSI/ASME B16.3-1992, Malleable Iron Threaded Fittings, IBR approved for § 3280.604(b).
(20) ANSI/ASME B16.4-1992, Gray Iron Threaded Fittings, IBR approved for § 3280.604(b).
(21) ANSI/ASME B16.15-1985, Cast Bronze Threaded Fittings, Classes 125 and 250, IBR approved for § 3280.604(b).
(22) ASME/ANSI B16.22-1989, Wrought-Copper and Copper Alloy Solder-Joint Pressure Fitting, IBR approved for § 3280.604(b).
(23) ASME B16.23-1992, Cast Copper Alloy Solder-Joint Drainage Fittings-DWV, IBR approved for § 3280.604(b).
(24) ASME/ANSI B16.26-1988, Cast Copper Alloy Fittings for Flared Copper Tubes, IBR approved for § 3280.604(b).
(25) ASME/ANSI B16.29-1986, Wrought Copper and Wrought Copper Alloy Solder-Joint Drainage Fittings-DWV, IBR approved for § 3280.604(b).
(26) ANSI/ASME B36.10-1979, Welding and Seamless Wrought Steel Pipe, IBR approved for §§ 3280.604(b), 3280.703, 3280.705(b), and 3280.706(b).
(o) American Society of Sanitary Engineering (ASSE), 901 Canterbury, Suite A, Westlake, OH 44145, phone number 440-835-3040, fax number 440-835-3488, Web site: http://www.asse-plumbing.org.
(1) ASSE 1001 (ANSI Approved 1990), Performance Requirements for Pipe Applied Atmospheric Type Vacuum Breakers, IBR approved for § 3280.604(b).
(2) ASSE 1002 Revision 5-1986 (ANSI/ASSE-1979), Performance Requirements for Water Closet Flush Tank Fill Valves (Ballcocks), IBR approved for § 3280.604(b).
(3) ASSE 1006 (ASSE/ANSI-1986), Plumbing Requirements for Residential Use (Household) Dishwashers, IBR approved for § 3280.604(b).
(4) ASSE 1007-1986, Performance Requirements for Home Laundry Equipment, IBR approved for § 3280.604(b).
(5) ASSE 1008-1986, Performance Requirements for Household Food Waste Disposer Units, IBR approved for § 3280.604(b).
(6) ASSE 1011-1981 (ANSI-1982), Performance Requirements for Hose Connection Vacuum Breakers, IBR approved for § 3280.604(b).
(7) ASSE 1014-1989 (ANSI-1990), Performance Requirements for Hand-held Showers, IBR approved for § 3280.604(b).
(8) ASSE 1016-2005, Performance Requirements for Automatic Compensating Values for Individual Shower and Tub/Shower Combinations, approved January 2005, IBR approved for §§ 3280.604(b) and 3280.607(b).
(9) ASSE 1017-1986, Performance Requirements for Temperature Activated Mixing Valves for Primary Domestic Use, IBR approved for § 3280.604(b).
(10) ANSI/ASSE 1019-1978, Performance Requirements for Wall Hydrants, Frost Proof Automatic Draining, Anti-Backflow Types, IBR approved for § 3280.604(b).
(11) ASSE 1023 (ANSI/ASSE-1979), Performance Requirements for Hot Water Dispensers, Household Storage Type Electrical, IBR approved for § 3280.604(b).
(12) ASSE 1025 (ANSI/ASSE-1978), Performance Requirements for Diverters for Plumbing Faucets with Hose Spray, Anti-Siphon Type, Residential Applications, IBR approved for § 3280.604(b).
(13) ASSE 1037-1990 (ANSI-1990), Performance Requirements for Pressurized Flushing Devices (Flushometers) for Plumbing Fixtures, IBR approved for § 3280.604(b).
(14) ASSE 1051 Revised 1996 (ANSI 1998), Performance Requirements for Air Admittance Valves for Plumbing Drainage Systems—Fixture and Branch Devices, IBR approved for § 3280.604(b).
(15) ASSE 1070-2004, Performance Requirements for Water Temperature Limiting Devices, IBR approved for §§ 3280.604(b) and 3280.607(b).
(p) American Society for Testing and Materials (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA 19428, (610) 832-9500, fax number 610-832-9555, Web site: http://www.astm.org.
(1) ASTM A53-93. Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless, IBR approved for §§ 3280.604(b) and 3280.703.
(2) ASTM A74-92, Standard Specification for Cast Iron Soil Pipe and Fittings, IBR approved for § 3280.604(b).
(3) ASTM A539-99, Standard Specification for Electric-Resistance-Welded Coiled Steel Tubing for Gas and Fuel Oil Lines, IBR approved for §§ 3280.703, 3280.705(b), and § 3280.706(b).
(4) ASTM B42-93, Standard Specification for Seamless Copper Pipe, Standard Sizes, IBR approved for §§ 3280.604 and 3280.703.
(5) ASTM B43-91, Standard Specification for Seamless Red Brass Pipe, Standard Sizes, IBR approved for §§ 3280.604(b) and 3280.705(b).
(6) ASTM B88-93, Standard Specification for Seamless Copper Water Tube, IBR approved for §§ 3280.604, 3280.703, 3280.705(b), and 3280.706(b).
(7) ASTM B251-93, Standard Specification for General Requirements for Wrought Seamless Copper and Copper-Alloy Tube, IBR approved for §§ 3280.604 and 3280.703.
(8) ASTM B280-95a, Standard Specification for Seamless Copper Tube for Air Conditioning and Refrigeration Field Service, IBR approved for §§ 3280.703, 3280.705(b), and 3280.706(b).
(9) ASTM B306-92, Standard Specification for Copper Drainage Tube (DWV), IBR approved for § 3280.604(b).
(10) ASTM C 36/C 36M-99, Standard Specification for Gypsum Wallboard, 1999, IBR approved for § 3280.304.
(11) ASTM C564-97, Standard Specification for Rubber Gaskets for Case Iron Soil Pipe and Fittings, approved December 10, 1997, IBR approved for §§ 3280.604(b) and 3280.611(d).
(12) ASTM C920-02, Standard Specification for Elastomeric Joint Sealants, approved January 10, 2002, IBR approved for § 3280.611(d).
(13) ASTM D781-68 (Reapproved 1973), Standard Test Methods for Puncture and Stiffness of Paperboard, and Corrugated and Solid Fiberboard, IBR approved for §§ 3280.304(b), and 3280.305(g).
(14) ASTM D2235-88, Standard Specification for Solvent Cement for Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe and Fittings, IBR approved for § 3280.604(b).
(15) ASTM D2564-91a, Standard Specification for Solvent Cements for Poly (Vinyl Chloride) (PVC) Plastic Piping Systems, IBR approved for § 3280.604(b).
(16) ASTM D2661-91, Standard Specification for Acrylonitrile-Butadiene-Styrene (ABS) Schedule 40 Plastic Drain, Waste, and Vent Pipe and Fittings, IBR approved for § 3280.604(b).
(17) ASTM D2665-91b, Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic Drain, Waste, and Vent Pipe and Fittings, IBR approved for § 3280.604(b).
(18) ASTM D2846-92, Standard Specification for Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Hot- and Cold-Water Distribution Systems, IBR approved for § 3280.604(b).
(19) ASTM D3309-92a, Standard Specification for Polybutylene (PB) Plastic Hot- and Cold-Water Distribution Systems, IBR approved for § 3280.604(b).
(20) ASTM D3311-92, Standard Specification for Drain, Waste, and Vent (DWV) Plastic Fittings Patterns, IBR approved for § 3280.604(b).
(21) ASTM D3953-97, Standard Specification for Strapping, Flat Steel, and Seals, approved April 10, 1997, IBR approved for §§ 3280.306(b) and 3280.306(g).
(22) ASTM D4442-92 (Reapproved 1997), Standard Test Methods for Direct Moisture Content Measurement of Wood and Wood-Base Materials, IBR approved for § 3280.304(b).
(23) ASTM D4444-92, Standard Test Methods for Use and Calibration of Hand-Held Moisture Meters, IBR approved for § 3280.304(b).
(24) ASTM D4635-01, Standard Specification for Polyethylene Films Made from Low-Density Polyethylene for General Use and Packaging Applications, approved June 10, 2001, IBR approved for § 3280.611(d).
(25) ASTM E84-01, Standard Test Method for Surface Burning Characteristics of Building Materials, 2001, IBR approved for § 3280.203(a).
(26) ASTM E 96-95 Standard Test Methods for Water Vapor Transmission of Materials, IBR approved for § 3280.504(a).
(27) ASTM E 162-94, Standard Test Method for Surface Flammability of Materials Using a Radiant Heat Energy Source, IBR approved for § 3280.203(a).
(28) ASTM E 773-97, Standard Test Methods for Accelerated Weathering of Sealed Insulating Glass Units, IBR approved for § 3280.403(d).
(29) ASTM E 774-97, Standard Specification for the Classification of the Durability of Sealed Insulating Glass Units, IBR approved for § 3280.403(d).
(30) ASTM E 1333-96, Standard Test Method for Determining Formaldehyde Concentrations in Air and Emission Rates from Wood Products Using a Large Chamber, approved March 10, 1996, IBR approved for § 3280.406(b).
(31) ASTM F628-91, Standard Specification for Acrylonitrile-Butadiene-Styrene (ABS) Schedule 40, Plastic Drain, Waste, and Vent Pipe with a Cellular Core, IBR approved for § 3280.604(b).
(32) ASTM F876-10, Standard Specification for Crosslinked Polyethylene (PEX) Tubing, approved February 10, 2010, IBR approved for § 3280.604(b).
(33) ASTM F877-07, Standard Specification for Crosslinked Polyethylene (PEX) Plastic Hot- and Cold-Water Distribution Systems, approved February 1, 2007, IBR approved for § 3280.604(b).
(q) Cast Iron Soil Pipe Institute (CISPI), 1064 Delaware Avenue SE, Atlanta, GA 30316, telephone number 404-622-0073, fax number 404-973-2845, Web site: http://www.cispi.org/.
(1) CISPI-301-90, Standard Specification for Hubless Cast Iron Soil Pipe and Fittings for Sanitary and Storm Drain, Waste, and Vent Piping Applications, IBR approved for § 3280.604(b).
(2) CISPI-HSN-85, Specification for Neoprene Rubber Gaskets for HUB and Spigot Cast Iron Soil Pipe and Fittings, IBR approved for §§ 3280.604, 3280.611(d).
(r) FS—Federal Specifications, General Services Administration, Specifications Branch, Room 6039, GSA Building, 7th and D Streets, SW., Washington, DC 20407.
(1) FS WW-P-541E/GEN-1980, Plumbing Fixtures (General Specifications), IBR approved for § 3280.604(b).
(2) FS ZZ-R-765B-1970, Silicone Rubber, (with 1971 Amendment), IBR approved for § 3280.611(d).
(s) HPVA (previously HPMA)—Hardwood Plywood and Veneer Association (HPVA) (previously named Hardwood Plywood Manufacturers Association (HPMA), 1825 Michael Faraday Drive, Reston, VA 22090, telephone number 703-435-2900, fax number 703-435-2537, Web site: http://www.hpva.org/.
(1) ANSI/HPVA HP-1-1994 (Approved 1995), American National Standard for Hardwood and Decorative Plywood, IBR approved for § 3280.304(b).
(2) HP-SG-96, Structural Design Guide for Hardwood Plywood Wall Panels, revised 1996, IBR approved for § 3280.304(b).
(t) HUD User, 11491 Sunset Hills Road, Reston, VA 20190-5254.
(1) HUD User No. 0005945, Overall U-values and Heating/Cooling Loads—Manufactured Homes, February 1992. IBR approved for § 3280.508(b).
(2) [Reserved]
(u) IIT Research Institute (IITRI), 10 West 35th Street, Chicago, IL 60616, telephone number 312-567-4000, Web site: http://www.iitri.org/.
(1) IITRI Fire and Safety Research Project J-6461 “Development of Mobile Home Fire Test Methods to Judge the Fire-Safe Performance of Foam Plastic Sheathing and Cavity Insulation”, 1979, IBR approved for § 3280.207(a).
(2) [Reserved]
(v) International Association of Plumbing and Mechanical Officials (IAPMO), 4755 East Philadelphia Street, Ontario, CA 91716, telephone number 909-472-4100, fax number 909-472-4150, Web site: http://www.iapmo.org.
(1) IAPMO PS 2-89, Material and Property Standard for Cast Brass and Tubing P-Traps, IBR approved for § 3280.604(b).
(2) IAPMO PS 4-90, Material and Property Standard for Drains for Prefabricated and Precast Showers, IBR approved for § 3280.604(b).
(3) IAPMO PS 5-84, Material and Property Standard for Special Cast Iron Fittings, IBR approved for § 3280.604(b).
(4) IAPMO PS 9-84, Material and Property Standard for Diversion Tees and Twin Waste Elbow, IBR approved for § 3280.604(b).
(5) IAPMO PS 14-89, Material and Property Standard for Flexible Metallic Water Connectors, IBR approved for § 3280.604(b).
(6) IAPMO PS 23-89, Material and Property Standard for Dishwasher Drain Airgaps, IBR approved for § 3280.604(b).
(7) IAPMO PS 31-91, Material and Property Standards for Backflow Prevention Assemblies, IBR approved for § 3280.604(b).
(8) IAPMO TSC 9-97, Standard for Gas Supply Connectors for Manufactured Homes, IBR approved for § 3280.703.
(9) IAPMO TSC 22-85, Standard for Porcelain Enameled Formed Steel Plumbing Fixtures, IBR approved for § 3280.604(b).
(w) Military Specifications and Standards, Naval Publications and Forms Center (MIL), 5801 Tabor Avenue, Philadelphia, PA 19120.
(1) MIL-L-10547E-1975, Liners, Case, and Sheet, Overwrap; Water-Vapor Proof or Waterproof, Flexible, IBR approved for § 3280.611(d).
(2) [Reserved]
(x) National Electrical Manufacturers Association (NEMA), 1300 North 17th Street, Suite 1752, Arlington, VA 22209, telephone number 703-841-3200, fax number 703-841-5900, Web site: http://www.nema.org/Pages/default.aspx.
(1) ANSI/NEMA WD-6-1997 Wiring Devices-Dimensional Specifications, IBR approved for § 3280.803(f).
(2) [Reserved]
(y) International Code Council Evaluation Service (NER), (previously known as National Evaluation Service), 5360 Workman Mill Road, Whittier, CA 90601-0543, telephone number 1-800-423-6587, ext. 66546, fax number 562-695-4694, Web site: http://www.icc-es.org.
(1) NER-272, National Evaluation Report, Power Driven Staples, Nails, and Allied Fasteners for Use in All Types of Building Construction, Reissued September 1, 1997, IBR approved for § 3280.304(b).
(2) [Reserved]
(z) National Fenestration Rating Council (NFRC), 6305 Ivy Lane, Suite 140, Greenbelt, MD 20770, telephone number 301-589-1776, fax number 301-589-3884, Web site: http://www.nfrc.org.
(1) NFRC 100, Procedure for Determining Fenestration Product U-factors, 1997 Edition, IBR approved for § 3280.508(e).
(2) [Reserved]
(aa) National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA 02269, phone number 617-770-3000, fax number 617-770-0700, Web site: http://www.nfpa.org.
(1) NFPA 31, Standard for the Installation of Oil Burning Equipment, 2001, IBR approved for §§ 3280.703 and 3280.707(f).
(2) NFPA 54-2002, National Fuel Gas Code, IBR approved for § 3280.703.
(3) NFPA 58, Liquefied Petroleum Gas Code, 2001 Edition, IBR approved for §§ 3280.703 and 3280.704(b).
(4) NFPA No. 70-2005, National Electrical Code, IBR approved as follows:
(i) Article 110.22, IBR approved for §§ 3280.803(k) and 3280.804(k).
(ii) Article 210.12(A) and (B), IBR approved for § 3280.801(b).
(iii) Article 220.61, IBR approved for § 3280.811(b).
(iv) Article 230, IBR approved for §§ 3280.803(k) and 3280.804(k).
(v) Article 250.24, IBR approved for §§ 3280.803(k) and 3280.804(k).
(vi) Article 250.26, IBR approved for §§ 3280.803(k) and 3280.804(k).
(vii) Article 250.28, IBR approved for §§ 3280.803(k) and 3280.804(k).
(viii) Article 312.2(A), IBR approved for §§ 3280.803(k) and 3280.804(k).
(x) Table 314.16(A), IBR approved for §§ 3280.808(m) and 3280.808(q).
(ix) Article 314.23(B), IBR approved for §§ 3280.808(m) and 3280.808(q).
(xi) Article 406.3, IBR approved for § 3280.807(d).
(xii) Article 410.4(D), IBR approved for § 3280.805(a).
(xiii) Article 440, IBR approved for § 3280.805(a).
(xiv) Article 440.65, IBR approved for § 3280.801(b).
(xv) Part II of Article 550, IBR approved for §§ 3280.801(a) and 3280.801(b).
(xvi) Article 550.25(a), IBR approved for § 3280.801(b).
(xvii) Article 680.70, IBR approved for §§ 3280.607(c) and 3280.801(a).
(xviii) Article 680.71, IBR approved for §§ 3280.607(c) and 3280.801(a).
(xix) Articles 680.72, IBR approved for §§ 3280.607(c) and 3280.801(a).
(5) NFPA 90B, Warm Air Heating and Air Conditioning Systems, 1996 Edition, IBR approved for § 3280.703.
(6) NFPA 220, Standard on Types of Building Construction, Chapter 2: definitions of “limited combustible” and “noncombustible material”, 1995 Edition, IBR approved for § 3280.202.
(7) NFPA 253, Standard Method of Test for Critical Radiant Flux of Floor Covering Systems Using a Radiant Heat Energy Source, 2000, IBR approved for § 3280.207(c).
(8) NFPA 255, Standard Method of Test of Surface Burning Characteristics of Building Materials, 1996, IBR approved for §§ 3280.203(a) and 3280.207(a).
(bb) U.S. Department of Commerce, National Institute of Standards and Technology (NIST), Office of Engineering Standards, Room A-166, Technical Building, Washington, DC 20234 and Voluntary Product Division, 100 Bureau Drive, Stop 2100, Gaithersburg, MD 20899-2100, telephone number 301- 975-4000, fax number 301-975-4715, Web site: http://www.nist.gov.
(1) PS 1-95, Construction and Industrial Plywood (With Typical APA Trademarks), IBR approved for § 3280.304(b).
(2) Voluntary Product Standard PS 2-04, Performance Standard for Wood-Based Structural-Use Panels, December 2004, IBR approval for § 3280.304(b).
(cc) National Sanitation Foundation (NSF), 789 North Dixboro Road, Ann Arbor, MI 48105, telephone number 734-769-8010, fax number 734-769-0109, Web site: http://www.nsf.org.
(1) ANSI/NSF 14-1990, Plastic Piping Components and Related Materials, IBR approved for § 3280.604(b).
(2) ANSI/NSF 24-1988, Plumbing System Components for Manufactured Homes and Recreational Vehicles, IBR approved for § 3280.604(b).
(3) ANSI/NSF 61-2001, Drinking Water System Components-Health Effects, IBR approved for § 3280.604(b).
(dd) Resources, Applications, Designs, & Controls (RADCO), 3220 East 59th Street, Long Beach, CA 90805, telephone number 562-272-7231, fax number 562-529-7513, Web site: http://www.radcoinc.com.
(1) RADCO DS-010-91, Decorative Gas Appliances for Installation in Solid Fuel Burning Fireplaces, May 1991, IBR approved for § 3280.703.
(2) [Reserved]
(ee) Society of Automotive Engineers (SAE), 400 Commonwealth Drive, Warrendale, PA 15096, telephone number 724-776-0790, Web site: http://www.sae.org/.
(1) SAE-J533b-1992, Flares for Tubing, IBR approved for §§ 3280.703 and 3280.705(f).
(2) [Reserved]
(ff) Steel Joist Institute (SJI), 234 West Cheves Street, Florence, SC 29501, telephone number 843-407-4091, Web site: http://steeljoist.org.
(1) Standard Specifications Load Tables and Weight Tables for Steel Joists and Joist Girders, SJI 1994, Fortieth Edition, IBR approved for § 3280.304(b).
(2) [Reserved]
(gg) Truss Plate Institute (TPI), 218 North Lee Street, Suite 312, Alexandria, VA 22314, telephone number 703-683-1010, fax number 866-501-4012, Web site: http://www.tpinst.org/index.html.
(1) TPI-85, Design Specifications for Metal Plate and Wood Connected Trusses, IBR approved for § 3280.304(b).
(2) [Reserved]
(hh) Underwriters' Laboratories, Inc. (UL), 333 Pfingsten Road, Northbrook, IL 60062, telephone number 847-272-8800, fax number 847-509-6257, Web site: http://www.ul.com.
(1) UL 94-1996, with 2001 revisions, Test for Flammability of Plastic Materials for Parts in Devices and Appliances, Fifth Edition, IBR approved for § 3280.715(e).
(2) UL 103-1995, with 1999 revisions, Factory-Built Chimneys for Residential Type and Building Heating Appliances, Ninth Edition, IBR approved for § 3280.703.
(3) UL 109-1997, with 2001 revisions, Tube Fittings for Flammable and Combustible Fluids, Refrigeration Service, and Marine Use, Sixth Edition, IBR approved for § 3280.703.
(4) UL 127-1996, with 1999 revisions, Factory-Built Fireplaces, Seventh Edition, IBR approved for § 3280.703.
(5) UL 174-1996, with 1997 revisions, Household Electric Storage Tank Water Heaters, Tenth Edition, IBR approved for § 3280.703.
(6) UL 181 Factory-Made Air Ducts and Air Connectors, Ninth Edition, April 4, 1996, with revisions through May 15, 2003, IBR approved for §§ 3280.702, 3280.703 and 3280.715(a).
(7) UL 181A, 1994, with 1998 revisions, Standard for Safety Closure Systems for use with Rigid Air Ducts and Air Connectors, Second Edition, IBR approved for §§ 3280.703 and 3280.715(c).
(8) UL 181B, 1995, with 1998 revisions, Standard for Safety Closure Systems for use with Flexible Air Ducts and Air Connectors, First Edition, IBR approved for §§ 3280.703 and 3280.715(c).
(9) UL 217, Single and Multiple Station Smoke Alarms, Fifth Edition, dated January 4, 1999, IBR approved for § 3280.208(a).
(10) UL 268, Smoke Detectors for Fire Protective Signaling Systems, Fourth Edition, dated January 4, 1999, IBR approved for § 3280.208(a).
(11) UL 307A-1995, Liquid Fuel-Burning Heating Appliances for Manufactured Homes and Recreational Vehicles, Seventh Edition, with 1997 revisions, IBR approved for §§ 3280.703 and 3280.707(f).
(12) UL 307B-1995, Gas Burning Heating Appliances for Manufactured Homes and Recreational Vehicles, Fourth Edition, with 1998 revisions, IBR approved for § 3280.703.
(13) UL 311, 1994, with 1998 revisions, Roof Jacks for Manufactured Homes and Recreational Vehicles, Eighth Edition, IBR approved for § 3280.703.
(14) UL 441, 1996 with 1999 revisions, Gas Vents, Ninth Edition, IBR approved for § 3280.703.
(15) UL 569, 1995 with 2001 revisions, Pigtails and Flexible Hose Connectors for LP-Gas, Seventh Edition, IBR approved for §§ 3280.703 and 3280.705(k).
(16) UL 737, 1996, Fireplace Stoves, Eight Edition, with 2000 revisions, IBR approved for § 3280.703.
(17) UL 923 Microwave Cooking Appliances, Fifth Edition, May 23, 2002, IBR approved for § 3280.204(c).
(18) UL 1042-1994, Electric Baseboard Heating Equipment, Fourth Edition, with 1998 revisions, IBR approved for § 3280.703.
(19) UL 1096, 1986, Electric Central Air Heating Equipment, Fourth Edition with revisions July 16, 1986, and January 30, 1988, IBR approved for § 3280.703.
(20) UL 1482, 1996, with 2000 revisions, Solid-Fuel Type Room Heaters, Fifth Edition, IBR approved for § 3280.703.
(21) UL 1995, 1995, Heating and Cooling Equipment, Second Edition, with 1999 revisions, IBR approved for § 3280.703.
(22) UL 2021-1997. Fixed and Location-Dedicated Electric Room Heaters, Second Edition, with 1998 revisions, IBR approved for § 3280.703.
(ii) Underwriters' Laboratories of Canada (ULC), 7 Underwriters Road, Toronto, Ontario, Canada M1 R 3A9, telephone number 866-937-3852, fax number 416-757-8727, Web site: http://www.ul.com/canada/eng/pages/.
(1) CAN/ULC S102.2-M88, Standard Method of Test for Surface Burning Characteristics of Floor Coverings and Miscellaneous Materials and Assemblies, Fourth Edition, April 1988, IBR approved for § 3280.207(b).
(2) [Reserved]
(jj) Window and Door Manufacturers Association (WDMA) (Previously known as the National Wood Window and Door Association, (NWWDA)), 2025 M Street, NW., Suite 800, Washington, DC 20036-3309, telephone number 202-367-1157, Web site: https://www.wdma.com.
(1) NWWDA I.S.4-81, Water Repellent Preservative Non-Pressure Treatment for Millwork, IBR approved for § 3280.405(b).
(2) [Reserved]
[78 FR 73976, Dec. 9, 2013, as amended at 79 FR 31863, June 3, 2014]
§ 3280.5
Data plate.
Each manufactured home shall bear a data plate affixed in a permanent manner near the main electrical panel or other readily accessible and visible location. Each data plate shall be made of material what will receive typed information as well as preprinted information, and which can be cleaned of ordinary smudges or household dirt without removing information contained on the data plate; or the data plate shall be covered in a permanent manner with materials that will make it possible to clean the data plate of ordinary dirt and smudges without obscuring the information. Each data plate shall contain not less than the following information:
(a) The name and address of the manufacturing plant in which the manufactured home was manufactured.
(b) The serial number and model designation of the unit, and the date the unit was manufactured.
(c) The applicable statement:
This manufactured home is designed to comply with the Federal Manufactured Home Construction and Safety Standards in force at the time of manufacture.or
This manufactured home has been substantially completed in accordance with an approved design and has been inspected (except for the components specifically identified in the instructions for completion on-site) in accordance with the Federal Manufactured Home Construction and Safety Standards and the requirements of the Department of Housing and Urban Development (HUD) in effect on the date of manufacture.
(d) A list of the certification label(s) number(s) that are affixed to each transportable manufactured section under § 3280.8.
(e) A list of major factory-installed equipment, including the manufacturer's name and the model designation of each appliance.
(f) Reference to the roof load zone and wind load zone for which the home is designed and duplicates of the maps as set forth in § 3280.305(c). This information may be combined with the heating/cooling certificate and insulation zone map required by §§ 3280.510 and 3280.511. The Wind Zone Map on the Data Plate shall also contain the statement:
This home has not been designed for the higher wind pressures and anchoring provisions required for ocean/coastal areas and should not be located within 1500′ of the coastline in Wind Zones II and III, unless the home and its anchoring and foundation system have been designed for the increased requirements specified for Exposure D in ANSI/ASCE 7-88.
(g) The statement:
This home has—has not—(appropriate blank to be checked by manufacturer) been equipped with storm shutters or other protective coverings for windows and exterior door openings. For homes designed to be located in Wind Zones II and III, which have not been provided with shutters or equivalent covering devices, it is strongly recommended that the home be made ready to be equipped with these devices in accordance with the method recommended in the manufacturers printed instructions.
(h) The statement: “Design Approval by”, followed by the name of the agency that approved the design.
[59 FR 2469, Jan. 14, 1994, as amended at 80 FR 53727, Sept. 8, 2015]
§ 3280.6
Serial number.
(a) A manufactured home serial number which will identify the manufacturer and the state in which the manufactured home is manufactured, must be stamped into the foremost cross member. Letters and numbers must be 3/8 inch minimum in height. Numbers must not be stamped into hitch assembly or drawbar.
§ 3280.7
Excluded structures.
Certain structures may be excluded from these Standards as modular homes under 24 CFR 3282.12.
[52 FR 4581, Feb. 12, 1987]
§ 3280.8
Waivers.
(a) Where any material piece of equipment, or system which does not meet precise requirements or specifications set out in the standard is shown, to the satisfaction of the Secretary, to meet an equivalent level of performance, the Secretary may waive the specifications set out in the Standard for that material, piece of equipment, or system.
(b) Where the Secretary is considering issuing a waiver to a Standard, the proposed waiver shall be published in the Federal Register for public comment, unless the Secretary, for good cause, finds that notice is impractical, unnecessary or contrary to the public interest, and incorporates into the waiver that finding and a brief statement of the reasons therefor.
(c) Each proposed and final waiver shall include:
(1) A statement of the nature of the waiver; and
(2) Identification of the particular standard affected.
(d) All waivers shall be published in the Federal Register and shall state their effective date. Where a waiver has been issued, the requirements of the Federal Standard to which the waiver relates may be met either by meeting the specifications set out in the Standard or by meeting the requirements of the waiver published in the Federal Register.
[58 FR 55003, Oct. 25, 1993]
§ 3280.9
Interpretative bulletins.
Interpretative bulletins may be issued for the following purposes:
(a) To clarify the meaning of the Standard; and
(b) To assist in the enforcement of the Standard.
[58 FR 55003, Oct. 25, 1993]
§ 3280.10
Use of alternative construction.
Requests for alternative construction can be made pursuant to 24 CFR 3282.14 of this chapter.
[58 FR 55003, Oct. 25, 1993]
§ 3280.11
Certification label.
(a) A permanent label shall be affixed to each transportable section of each manufactured home for sale or lease in the United States. This label shall be separate and distinct from the data plate which the manufacturer is required to provide under § 3280.5 of the standards.
(b) The label shall be approximately 2 in. by 4 in. in size and shall be permanently attached to the manufactured home by means of 4 blind rivets, drive screws, or other means that render it difficult to remove without defacing it. It shall be etched on 0.32 in. thick aluminum plate. The label number shall be etched or stamped with a 3 letter designation which identifies the production inspection primary inspection agency and which the Secretary shall assign. Each label shall be marked with a 6 digit number which the label supplier shall furnish. The labels shall be stamped with numbers sequentially.
(c) The label shall read as follows:
As evidenced by this label No. ABC 000001, the manufacturer certifies to the best of the manufacturer's knowledge and belief that this manufactured home has been inspected in accordance with the requirements of the Department of Housing and Urban Development and is constructed in conformance with the Federal manufactured home construction and safety standards in effect on the date of manufacture. See date plate.
(d) The label shall be located at the tail-light end of each transportable section of the manufactured home approximately one foot up from the floor and one foot in from the road side, or as near that location on a permanent part of the exterior of the manufactured home unit as practicable. The road side is the right side of the manufactured home when one views the manufactured home from the tow bar end of the manufactured home.
[42 FR 960, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 47553, Dec. 15, 1987. Redesignated and amended at 58 FR 55003, Oct. 25, 1993]

Subpart B—Planning Considerations
§ 3280.101
Scope.
Subpart B states the planning requirements in manufactured homes. The intent of this subpart is to assure the adequacy of architectural planning considerations which assist in determining a safe and healthful environment.
§ 3280.102
Definitions.
(a) Gross floor area means all space, wall to wall, including recessed entries not to exceed 5 sq. ft. and areas under built-in vanities and similar furniture. Where the ceiling height is less than that specified in § 3280.104, the floor area under such ceilings shall not be included. Floor area of closets shall not be included in the gross floor area.
(b) Habitable room means a room or enclosed floor space arranged for living, eating, food preparation, or sleeping purposes not including bathrooms, foyers, hallways, and other accessory floor space.
(c) Laundry area means an area containing or designed to contain a laundry tray, clothes washer and/or clothes dryer.
§ 3280.103
Light and ventilation.
(a) Lighting. Each habitable room shall be provided with exterior windows and/or doors having a total glazed area of not less than 8 percent of the gross floor area.
(1) Kitchens, bathrooms, toilet compartments, laundry areas, and utility rooms may be provided with artificial light in place of windows.
(2) Rooms and areas may be combined for the purpose of providing the required natural lighting provided that at least one half of the common wall area is open and unobstructed, and the open area is at least equal to 10 percent of the combined floor area or 25 square feet whichever is greater.
(b) Whole-house ventilation. Each manufactured home must be provided with whole-house ventilation having a minimum capacity of 0.035 ft^3/min/ft^2 of interior floor space or its hourly average equivalent. This ventilation capacity must be in addition to any openable window area. In no case shall the installed ventilation capacity of the system be less than 50 cfm nor more than 90 cfm. The following criteria must be adhered to:
(1) The ventilation capacity must be provided by a mechanical system or a combination passive and mechanical system. The ventilation system or provisions for ventilation must not create a positive pressure in Uo Value Zone 2 and Zone 3 or a negative pressure condition in Uo Value Zone 1. Mechanical systems must be balanced. Combination passive and mechanical systems must have adequately sized inlets or exhaust to release any unbalanced pressure. Temporary pressure imbalances due to gusting or high winds are permitted.
(2) The ventilation system or provisions for ventilation must exchange air directly with the exterior of the home, except the ventilation system, or provisions for ventilation must not draw or expel air with the space underneath the home. The ventilation system or provisions for ventilation must not draw or expel air into the floor, wall, or ceiling/roof systems, even if those systems are vented. The ventilation system must be designed to ensure that outside air is distributed to all bedrooms and main living areas. The combined use of undercut doors or transom grills connecting those areas to the room where the mechanical system is located is deemed to meet this requirement.
(3) The ventilation system or a portion of the system is permitted to be integral with the home's heating or cooling system. The system must be capable of operating independently of the heating or cooling modes. A ventilation system that is integral with the heating or cooling system is to be listed as part of the heating and cooling system or listed as suitable for use with that system.
(4) A mechanical ventilation system, or mechanical portion thereof, must be provided with a manual control, and must be permitted to be provided with automatic timers or humidistats.
(5) A whole-house ventilation label must be attached to the whole-house ventilation control, must be permanent, and must state: “WHOLE-HOUSE VENTILATION”.
(6) Instructions for correctly operating and maintaining whole-house ventilation systems must be included with the homeowner's manual. The instructions must encourage occupants to operate these systems whenever the home is occupied, and must refer to the labeled whole-house ventilation control.
(c) Additional ventilation. (1) At least half of the minimum required glazed area in paragraph (a) of this section shall be openable directly to the outside of the manufactured home for unobstructed ventilation. These same ventilation requirements apply to rooms combined in accordance with § 3280.103(a)(2).
(2) Kitchens shall be provided with a mechanical ventilation system that is capable of exhausting 100 cfm to the outside of the home. The exhaust fan shall be located as close as possible to the range or cook top, but in no case farther than 10 feet horizontally from the range or cook top.
(3) Each bathroom and separate toilet compartment shall be provided with a mechanical ventilation system capable of exhausting 50 cfm to the outside of the home. A separate toilet compartment may be provided with 1.5 square feet of openable glazed area in place of mechanical ventilation, except in Uo value Zone 3.
[58 FR 55003, Oct. 25, 1993, as amended at 70 FR 72042, Nov. 30, 2005]
§ 3280.104
Ceiling heights.
(a) Every habitable room and bathroom shall have a minimum ceiling height of not less than 7 feet, 0 inches for a minimum of 50 percent of the room's floor area. The remaining area may have a ceiling with a minimum height of 5 feet, 0 inches. Minimum height under dropped ducts, beams, etc. shall be 6 feet, 4 inches.
(b) Hallways and foyers shall have a minimum ceiling height of 6 feet, 6 inches.
§ 3280.105
Exit facilities; exterior doors.
(a) Number and location of exterior doors. Manufactured homes shall have a minimum of two exterior doors located remote from each other.
(1) Required egress doors shall not be located in rooms where a lockable interior door must be used in order to exit.
(2) In order for exit doors to be considered remote from each other, they must comply with all of the following:
(i) Both of the required doors must not be in the same room or in a group of rooms which are not defined by fixed walls.
(ii) Single wide units. Doors may not be less than 12 ft. c-c from each other as measured in any straight line direction regardless of the length of path of travel between doors.
(iii) Double wide units. Doors may not be less than 20 ft. c-c from each other as measured in any straight line direction regardless of the length of path of travel between doors.
(iv) One of the required exit doors must be accessible from the doorway of each bedroom without traveling more than 35 feet. The travel distance to the exit door must be measured on the floor or other walking surface along the center-line of the natural and unobstructed path of travel starting at the center of the bedroom door, curving around any corners or permanent obstructions with a one-foot clearance from, and ending at, the center of the exit door.
(b) Door design and construction. (1) Exterior swinging doors shall be constructed in accordance with § 3280.405 the “Standard for Swinging Exterior Passage Doors for Use in Manufactured Homes”. Exterior sliding glass doors shall be constructed in accordance with § 3280.403 the “Standard for Windows and Sliding Glass Doors Used in Manufactured Homes”.
(2) All exterior swinging doors must provide a minimum 28-inch wide × 74-inch high clear opening. Door seals are permitted to reduce the opening, either vertically or horizontally, a maximum of one inch. All exterior sliding glass doors must provide a minimum 28-inch wide × 72-inch high clear opening.
(3) Each swinging exterior door other than screen or storm doors shall have a key-operated lock that has a deadlocking latch or a key-operated dead bolt with a passage latch. Locks shall not require the use of a key for operation from the inside.
(4) All exterior doors, including storm and screen doors, opening outward shall be provided with a safety door check.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 50 FR 9269, Mar. 7, 1985; 78 FR 73981, Dec. 9, 2013]
§ 3280.106
Exit facilities; egress windows and devices.
(a) Every room designed expressly for sleeping purposes, unless it has an exit door (see § 3280.105), shall have at least one outside window or approved exit device which meets the requirements of § 3280.404, the “Standard for Egress Windows and Devices for Use in Manufactured Homes.”
(b) The bottom of the window opening shall not be more than 36 inches above the floor.
(c) Locks, latches, operating handles, tabs, and any other window screen or storm window devices which need to be operated in order to permit exiting, shall not be located in excess of 54 inches from the finished floor.
(d) Integral rolled-in screens shall not be permitted in an egress window unless the window is of the hinged-type.
[49 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 49 FR 36086, Sept. 14, 1984; 52 FR 4581, Feb. 12, 1987]
§ 3280.107
Interior privacy.
Bathroom and toilet compartment doors shall be equipped with a privacy lock.
§ 3280.108
Interior passage.
(a) Interior doors having passage hardware without a privacy lock, or with a privacy lock not engaged, shall open from either side by a single movement of the hardware mechanism in any direction.
(b) Each manufactured home interior door, when provided with a privacy lock, shall have a privacy lock that has an emergency release on the outside to permit entry when the lock has been locked by a locking knob, lever, button, or other locking device on the inside.
§ 3280.109
Room requirements.
(a) Every manufactured home shall have at least one living area with not less than 150 sq. ft. of gross floor area.
(b) Rooms designed for sleeping purposes shall have a minimum gross square foot floor area as follows:
(1) All bedrooms shall have at least 50 sq. ft. of floor area.
(2) Bedrooms designed for two or more people shall have 70 sq. ft. of floor area plus 50 sq. ft. for each person in excess of two.
(c) Every room designed for sleeping purposes shall have accessible clothes hanging space with a minimum inside depth of 22 inches and shall be equipped with a rod and shelf.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, and further redesignated at 58 FR 55004, Oct. 25, 1993]
§ 3280.110
Minimum room dimensions.
The gross floor area required by § 3280.110 (a) and (b) shall have no clear horizontal dimension less than 5 feet except as permitted by § 3280.102(a).
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, and further redesignated at 58 FR 55004, Oct. 25, 1993]
§ 3280.111
Toilet compartments.
Each toilet compartment must have a minimum width of 30 inches, with a minimum clear space of 21 inches in front of each toilet. A toilet located adjacent to a wall must have the center-line of the toilet located a minimum of 15 inches from the wall. A toilet located adjacent to a tub must have the center-line of the toilet located a minimum of 12 inches from the outside edge of the tub.
[78 FR 73981, Dec. 9, 2013]
§ 3280.112
Hallways.
Hallways shall have a minimum horizontal dimension of 28 inches measured from the interior finished surface to the interior finished surface of the opposite wall. When appliances are installed in a laundry area, the measurement shall be from the front of the appliance to the opposite finished interior surface. When appliances are not installed and a laundry area is provided, the area shall have a minimum clear depth of 27 inches in addition to the 28 inches required for passage. In addition, a notice of the available clearance for washer/dryer units shall be posted in the laundry area. Minor protrusions into the minimum hallway width by doorknobs, trim, smoke alarms or light fixtures are permitted.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, and further redesignated at 58 FR 55004, Oct. 25, 1993; 67 FR 12817, Mar. 19, 2002]
§ 3280.113
Glass and glazed openings.
(a) Windows and sliding glass doors. All windows and sliding glass doors shall meet the requirements of § 3280.403 the “Standard for Windows and Sliding Glass Doors Used in Manufactured Homes”.
(b) Hazardous locations requiring safety glazing. Except as provided in paragraph (d) of this section, the following locations and areas require the use of safety glazing conforming to the requirements of paragraph (c) of this section:
(1) Glazing in all entrance or exit doors;
(2) Glazing in fixed and sliding panels of sliding glass doors;
(3) Glazing in storm-type doors;
(4) Glazing in unframed side-hinged swinging doors;
(5) Glazing in doors and fixed panels less than 60 inches above the room floor level that enclose bathtubs, showers, hydromassage tubs, hot tubs, whirlpools, saunas;
(6) Glazing within 12 inches horizontally, as measured from the edge of the door in the closed position, and 60 inches vertically as measured from the room floor level, adjacent to and in the same plane of a door;
(7) Glazing within 36 inches of an interior room walking surface when the glazing meets all of the following:
(i) Individual glazed panels exceed 9 square feet in area in an exposed surface area;
(ii) The bottom edge of the exposed glazing is less than 19 inches above the room floor level; and
(iii) The top edge of the exposed glazing is greater than 36 inches above the room floor level.
(8) Glazing in rails and guardrails; and
(9) Glazing in unbacked mirrored wardrobe doors (i.e., mirrors that are not secured to a backing that is capable of being the door itself).
(c) Safety glazing material is considered to be any glazing material capable of meeting the requirements of Consumer Product Safety Commission 16 CFR part 1201, or Standard for Safety Glazing Materials used in Buildings —Safety Performance Specifications and Methods of Test, ANSI Z97.1-2004 (incorporated by reference, see § 3280.4).
(d) Glazing in the following locations is not required to meet the requirements in paragraph (b) of this section:
(1) Openings in doors through which a 3-inch sphere is unable to pass;
(2) Leaded and decorative glazed panels;
(3) Glazing in jalousie-type doors;
(4) Glazing as described in paragraph (b)(6) of this section when an intervening wall or other permanent barrier exists between the door and the glazing;
(5) Glazing as described in paragraph (b)(7) of this section when a protective bar or member is installed horizontally between 34 inches and 38 inches above the room floor level, as long as the bar or member is a minimum of 11/2 inches in height and capable of resisting a horizontal load of 50 pounds per lineal foot; and
(6) Mirrors mounted on a flush door surface or solid wall surface.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4581, Feb. 12, 1987. Redesignated at 58 FR 55004, Oct. 25, 1993; 78 FR 73981, Dec. 9, 2013]

Subpart C—Fire Safety

Source:
49 FR 32008, Aug. 9, 1984, unless otherwise noted.
§ 3280.201
Scope.
The purpose of this subpart is to set forth requirements that will assure reasonable fire safety to the occupants by reducing fire hazards and by providing measures for early detection.
§ 3280.202
Definitions.
The following definitions are applicable to subparts C, H, and I of the Standards:
Combustible material: Any material not meeting the definition of limited-combustible or non-combustible material.
Flame-spread rating: The measurement of the propagation of flame on the surface of materials or their assemblies as determined by recognized standard tests conducted as required by this subpart.
Interior finish: The surface material of walls, fixed or movable partitions, ceilings, columns, and other exposed interior surfaces affixed to the home's structure including any materials such as paint or wallpaper and the substrate to which they are applied. Interior finish does not include:
(1) Trim and sealant 2 inches or less in width adjacent to the cooking range and in furnace and water heater spaces provided it is installed in accordance with the requirements of § 3280.203(b)(3) or (4), and trim 6 inches or less in width in all other areas;
(2) Windows and frames;
(3) Single doors and frames and a series of doors and frames not exceeding 5 feet in width;
(4) Skylights and frames;
(5) Casings around doors, windows, and skylights not exceeding 4 inches in width;
(6) Furnishings which are not permanently affixed to the home's structure;
(7) Baseboards not exceeding 6 inches in height;
(8) Light fixtures, cover plates of electrical receptacle outlets, switches, and other devices;
(9) Decorative items attached to walls and partitions (i.e., pictures, decorative objects, etc.) constituting no more than 10% of the aggregate wall surface area in any room or space not more than 32 square feet in surface area, whichever is less;
(10) Plastic light diffusers when suspended from a material which meets the interior finish provisions of § 3280.203(b);
(11) Coverings and surfaces of exposed wood beams; and
(12) Decorative items including the following:
(i) Non-structural beams not exceeding 6 inches in depth and 6 inches in width and spaced not closer than 4 feet on center;
(ii) Non-structural lattice work;
(iii) Mating and closure molding; and
(iv) Other items not affixed to the home's structure.
Limited combustible: A material meeting:
(1) The definition contained in Chapter 2 of NFPA 220-1995, Standard on Types of Building Construction; or
(2) 5/16-inch or thicker gypsum board.
Noncombustible material: A material meeting the definition contained in Chapter 2 of NFPA 220-1995, Standard on Types of Building Construction.
Smoke alarm: An alarm device that is responsive to smoke.
Tactile notification appliance: A notification appliance that alerts by the sense of touch or vibration.
[58 FR 55004, Oct. 25, 1993, as amended at 67 FR 12817, Mar. 19, 2002; 70 FR 72042, Nov. 30, 2005]
§ 3280.203
Flame spread limitations and fire protection requirements.
(a) Establishment of flame spread rating. The surface flame spread rating of interior-finish material must not exceed the value shown in § 3280.203(b) when tested by Standard Test Method for Surface Burning Characteristics of Building Materials, ASTM E84-01, 2001, or Standard Method of Test of Surface Burning Characteristics of Building Materials NFPA 255, 1996, except that the surface flame spread rating of interior-finish materials required by § 3280.203(b)(5) and (6) may be determined by using the Standard Test Method for Surface Flammability of Materials Using a Radiant Heat Energy Source, ASTM E 162-94. However, the following materials need not be tested to establish their flame spread rating unless a lower rating is required by the standards in this part:
(1) Flame-spread rating—76 to 200.
(i) .035-inch or thicker high pressure laminated plastic panel countertop;
(ii) 1/4-inch or thicker unfinished plywood with phenolic or urea glue;
(iii) Unfinished dimension lumber (1-inch or thicker nominal boards);
(iv) 3/8-inch or thicker unfinished particleboard with phenolic or urea binder;
(v) Natural gum-varnished or latex- or alkyd-painted:
(A) 1/4-inch or thicker plywood, or
(B) 3/8-inch or thicker particleboard, or
(C) 1-inch or thicker nominal board;
(vi) 5/16-inch gypsum board with decorative wallpaper; and
(vii) 1/4-inch or thicker unfinished hardboard,
(2) Flame-spread rating-25 to 200,
(i) Painted metal;
(ii) Mineral-base acoustic tile;
(iii) 5/16-inch or thicker unfinished gypsum wallboard (both latex- or alkyd-painted); and
(iv) Ceramic tile.
(The above-listed material applications do not waive the requirements of § 3280.203(c) or § 3280.204 of this subpart.)
(b) Flame-spread rating requirements.
(1) The interior finish of all walls, columns, and partitions shall not have a flame spread rating exceeding 200 except as otherwise specified herein.
(2) Ceiling interior finish shall not have a flame spread rating exceeding 75.
(3) Walls adjacent to or enclosing a furnace or water heater and ceilings above them shall have an interior finish with a flame spread rating not exceeding 25. Sealants and other trim materials 2 inches or less in width used to finish adjacent surfaces within these spaces are exempt from this provision provided that all joints are completely supported by framing members or by materials having a flame spread rating not exceeding 25.
(4) Exposed interior finishes adjacent to the cooking range shall have a flame spread rating not exceeding 50, except that backsplashes not exceeding 6 inches in height are exempted. Adjacent surfaces are the exposed vertical surfaces between the range top height and the overhead cabinets and/or ceiling and within 6 horizontal inches of the cooking range. (Refer also to § 3280.204(a), Kitchen Cabinet Protection.) Sealants and other trim materials 2 inches or less in width used to finish adjacent surfaces are exempt from this provision provided that all joints are completely supported by a framing member.
(5) Kitchen cabinet doors, countertops, backsplashes, exposed bottoms, and end panels shall have a flame spread rating not to exceed 200. Cabinet rails, stiles, mullions, and top strips are exempted.
(6) Finish surfaces of plastic bathtubs, shower units, and tub or shower doors shall not exceed a flame spread rating of 200.
(c) Fire protective requirements.
(1) Materials used to surface the following areas shall be of limited combustible material (e.g., 5/16-inch gypsum board, etc.):
(i) The exposed wall adjacent to the cooking range (see § 3280.203(b)(4));
(ii) Exposed bottoms and sides of kitchen cabinets as required by § 3280.204;
(iii) Interior walls and ceilings enclosing furnace and/or water heater spaces; and
(iv) Combustible doors which provide interior or exterior access to furnace and/or water heater spaces. The surface may be interrupted for louvers ventilating the enclosure. However, the louvers shall not be constructed of a material of greater combustibility than the door itself (e.g., plastic louvers on a wooden door).
(2) No burner of a surface cooking unit shall be closer than 12 horizontal inches to a window or an exterior door with glazing.
[49 FR 32008, Aug. 9, 1984, as amended at 58 FR 55005, Oct. 25, 1993; 70 FR 72042, Nov. 30, 2005]
§ 3280.204
Kitchen cabinet protection.
(a) The bottom and sides of combustible kitchen cabinets over cooking ranges to a horizontal distance of 6 inches from the outside edge of the cooking range shall be protected with at least 5/16-inch thick gypsum board or equivalent limited combustible material. One-inch nominal framing members and trim are exempted from this requirement. The cabinet area over the cooking range or cooktops shall be protected by a metal hood (26-gauge sheet metal, or .017 stainless steel, or .024 aluminum, or .020 copper) with not less than a 3-inch eyebrow projecting horizontally from the front cabinet face. The 5/16-inch thick gypsum board or equivalent material which is above the top of the hood may be supported by the hood. A 3/8-inch enclosed air space shall be provided between the bottom surface of the cabinet and the gypsum board or equivalent material. The hood shall be at least as wide as the cooking range.
(b) The 3-inch metal eyebrow required by paragraph (a) of this section will project from the front and rear cabinet faces when there is no adjacent surface behind the range, or the 5/16-inch thick gypsum board or equivalent material shall be extended to cover all exposed rear surfaces of the cabinet.
(c) Alternative compliance. When all exposed surfaces along the bottoms and sides of combustible kitchen cabinets are protected as described in paragraph (a) of this section, the metal hood, the 5/16-inch thick gypsum board or equivalent material, and the 3/8-inch airspace required by paragraph (a) of this section can be omitted, provided that:
(1) A microwave oven is installed between the cabinet and the range; and
(2) The microwave oven is equivalent in fire protection to the metal range hood required by paragraph (a) of this section; and
(3) The microwave oven is certified to be in conformance with Microwave Cooking Appliances, UL 923-2002 (incorporated by reference, see § 3280.4).
(d) When a manufactured home is designed for the future installation of a cooking range, the metal hood and cabinet protection required by paragraph (a) of this section and the wall-surfacing protection behind the range required by § 3280.203 shall be installed in the factory.
(e) Vertical clearance above cooking top. Ranges shall have a vertical clearance above the cooking top of not less than 24 inches to the bottom of combustible cabinets.
[49 FR 32008, Aug. 9, 1984, as amended at 78 FR 73982, Dec. 9, 2013]
§ 3280.205
Carpeting.
Carpeting shall not be used in a space or compartment designed to contain only a furnace and/or water heater. Carpeting may be used in other areas where a furnace or water heater is installed, provided that it is not located under the furnace or water heater.
§ 3280.206
Fireblocking.
(a) General. Fireblocking must comply with the requirements of this section. The integrity of all fireblocking materials must be maintained.
(b) Fireblocking materials. Fireblocking must consist of the following materials:
(1) Minimum one inch nominal lumber, 5/16 inch thick gypsum board, or equivalent fire resistive materials; or
(2) Other Listed or Approved Materials;
(c) Fireblocking locations. (1) Fireblocking must be installed in concealed spaces of stud walls, partitions, and furred spaces at the floor and ceiling levels. Concealed spaces must not communicate between floor levels. Concealed spaces must not communicate between a ceiling level and a concealed roof area, or an attic space.
(2) Fireblocking must be installed at the interconnection of a concealed vertical space and a concealed horizontal space that occurs:
(i) Between a concealed wall cavity and the ceiling joists above; and
(ii) At soffits, drop ceilings, cover ceilings, and similar locations.
(3) Fireblocking must be installed around the openings for pipes, vents, and other penetrations in walls, floors, and ceilings of furnace and water heater spaces. Pipes, vents, and other penetrations that cannot be moved freely within their opening are considered to be fireblocked. Materials used to fireblock heat producing vent penetrations must be noncombustible or limited combustible types.
[71 FR 72042, Nov. 30, 2005]
§ 3280.207
Requirements for thermal insulating materials.
(a) General. Except for foam plastic materials and as provided in this section, exposed and concealed thermal insulating materials, including any facings, must be tested in accordance with NFPA 255-96, Standard Method of Test of Surface Burning Characteristics of Building Materials (incorporated by reference, see § 3280.4) and must have a flame spread index of 25 or less and a smoke developed index of 450 or less. The flame spread and smoke developed limitations do not apply to:
(1) Coverings and facings of insulation batts or blankets installed in concealed spaces when the facings are in substantial contact with the unexposed surface of wall, floor, or ceiling finish; or
(2) Cellulose loose-fill insulation that complies with paragraph (b) of this section.
(b) Loose-fill insulation. (1) Cellulose loose-fill insulation that is not spray-applied or self-supporting must comply with, and each package must be labeled in accordance with the Consumer Product Safety Commission requirements in 16 CFR parts 1209 and 1404.
(2) Other loose-fill insulation that cannot be mounted in the NFPA 255-96, test apparatus without a screen or other artificial support must be tested in accordance with CAN/ULC S102.2-M88, Standard Method of Test for Surface Burning Characteristics of Floor Coverings and Miscellaneous Materials and Assemblies (incorporated by reference, see § 3280.4), and must have a flame spread index of 25 or less and a smoke developed index of 450 or less.
(c) Attic locations. Exposed insulation installed on the floor or ceiling forming the lower boundary of the attic must be tested in accordance with NFPA 253-2000, Standard Method of Test for Critical Radiant Flux of Floor Covering Systems Using a Radiant Heat Energy Source (incorporated by reference, see § 3280.4) and must have a critical radiant flux of not less than 0.12 watt/cm^2.
§ 3280.208
Requirements for foam plastic thermal insulating materials.
(a) General. Foam plastic thermal insulating materials shall not be used within the cavity of walls (not including doors) or ceilings or be exposed to the interior of the home unless:
(1) The foam plastic insulating material is protected by an interior finish of 5/16-inch thick gypsum board or equivalent material for all cavities where the material is to be installed; or
(2) The foam plastic is used as a sheathing or siding backerboard, and it:
(i) Has a flame spread rating of 75 or less and a smoke-developed rating of 450 or less (not including outer covering of sheathing);
(ii) Does not exceed 3/8-inch in thickness; and
(iii) Is separated from the interior of the manufactured home by a minimum of 2 inches of mineral fiber insulation or an equivalent thermal barrier; or
(3) The foam plastic insulating material has been previously accepted by the Department for use in wall and/or ceiling cavities of manufactured homes, and it is installed in accordance with any restrictions imposed at the time of that acceptance; or
(4) The foam plastic insulating material has been tested as required for its location in wall and/or ceiling cavities in accordance with testing procedures described in the Illinois Institute of Technology Research Institute (IIT) Report, “Development of Mobile Home Fire Test Methods to Judge the Fire-Safe Performance of Foam Plastic Sheathing and Cavity Insulation, IITRI Fire and Safety Research Project J-6461, 1979” or other full-scale fire tests accepted by HUD, and it is installed in a manner consistent with the way the material was installed in the foam plastic test module. The materials must be capable of meeting the following acceptance criteria required for their location:
(i) Wall assemblies. The foam plastic system shall demonstrate equivalent or superior performance to the control module as determined by:
(A) Time to reach flashover (600 °C in the upper part of the room);
(B) Time to reach an oxygen (O2) level of 14% (rate of O2 depletion), a carbon monoxide (CO) level of 1%, a carbon dioxide (CO2) level of 6%, and a smoke level of 0.26 optical density/meter measured at 5 feet high in the doorway; and
(C) Rate of change concentration for O2, CO, CO2 and smoke measured 3 inches below the top of the doorway.
(ii) Ceiling assemblies. A minimum of three valid tests of the foam plastic system and one valid test of the control module shall be evaluated to determine if the foam plastic system demonstrates equivalent or superior performance to the control module. Individual factors to be evaluated include intensity of cavity fire (temperature-time) and post-test damage.
(iii) Post-test damage assessment for wall and ceiling assemblies. The overall performance of each total system shall also be evaluated in determining the acceptability of a particular foam plastic insulating material.
(b) All foam plastic thermal insulating materials used in manufactured housing shall have a flame spread rating of 75 or less (not including outer covering or sheathing) and a maximum smoke-developed rating of 450.
[49 FR 32008, Aug. 9, 1984, as amended at 70 FR 72043, Nov. 30, 2005. Redesignated at 78 FR 73982, Dec. 9, 2013]
§ 3280.209
Smoke alarm requirements.
(a) Labeling. Each smoke alarm required under paragraph (b) of this section must conform with the requirements of UL 217, Single and Multiple Station Smoke Alarms, dated January 4, 1999 (incorporated by reference, see § 3280.4), or UL 268, Smoke Detectors for Fire Protective Signaling Systems, dated January 4, 1999 (incorporated by reference, see § 3280.4), and must bear a label to evidence conformance.
(b) Required smoke alarm locations. (1) At least one smoke alarm must be installed in each of the following locations:
(i) To protect both the living area and kitchen space. Manufacturers are encouraged to locate the alarm in the living area remote from the kitchen and cooking appliances. A smoke alarm located within 20 feet horizontally of a cooking appliance must incorporate a temporary silencing feature or be of a photoelectric type.
(ii) In each room designed for sleeping.
(iii) On the ceiling of the upper level near the top or above each stairway, other than a basement stairway, in any multistory home completed in accordance with this part or part 3282 of this chapter. The alarm must be located so that smoke rising in the stairway cannot be prevented from reaching the alarm by an intervening door or obstruction.
(2) For each home designed to be placed over a basement, the manufacturer must provide a smoke alarm for the basement and must install at the factory an electrical junction box for the installation of this smoke alarm and for its interconnection to other smoke alarms required by this section. The instructions for installers and information for homeowners required in paragraph (f) of this section must clearly indicate that a smoke alarm should be installed and is to be located on the basement ceiling near the stairway.
(3) A smoke alarm required under this section must not be placed in a location that impairs its effectiveness or in any of the following locations:
(i) Within 3 feet horizontally from any discharge grille when a home is equipped or designed for future installation of a roof-mounted evaporative cooler or other equipment discharging conditioned air through a ceiling grille into the living space; and
(ii) In any location or environment that is prohibited by the terms of its listing, except as permitted by this section.
(c) Mounting requirements. (1) Except in rooms with peaked sloping or shed sloping ceilings with a slope of more than 1.5/12 or as permitted pursuant to paragraph (e) of this section, smoke alarms must be mounted either:
(i) On the ceiling at least 4 inches from each wall; or
(ii) On a wall with the top of the alarm not less than 4 inches below the ceiling, and not farther from the ceiling than 12 inches or the distance from the ceiling specified in the smoke alarm manufacturer's listing and instructions, whichever is less.
(2) Except as permitted pursuant to paragraph (e) of this section, in rooms with peaked sloping ceilings with a slope of more than 1.5/12, smoke alarms must be mounted on the ceiling within 3 feet, measured horizontally, from the peak of the ceiling; at least 4 inches, measured vertically, below the peak of the ceiling; and at least 4 inches from any projecting structural element.
(3) Except as permitted pursuant to paragraph (e) of this section, in rooms with shed sloping ceilings with a slope of more than 1.5/12, smoke alarms must be mounted on the ceiling within 3 feet, measured horizontally, of the high side of the ceiling, and not closer than 4 inches from any adjoining wall surface and from any projecting structural element.
(d) Connection to power source. (1) Each smoke alarm must be powered from:
(i) The electrical system of the home as the primary power source and a battery as a secondary power source; or
(ii) A battery rated for a 10-year life, provided the smoke alarm is listed for use with a 10-year battery.
(2) Each smoke alarm whose primary power source is the home electrical system must be mounted on an electrical outlet box and connected by a permanent wiring method to a general electrical circuit. More than one smoke alarm is permitted to be placed on the same electrical circuit. The wiring circuit for the alarm must not include any switches between the over-current protective device and the alarm, and must not be protected by a ground fault circuit interrupter.
(3) Smoke alarms required under this section must be interconnected such that the activation of any one smoke alarm causes the alarm to be triggered in all required smoke alarms in the home.
(e) Visible and tactile notification appliances. (1) In addition to the smoke alarms required pursuant to this section, the manufacturer must provide visible and listed tactile notification appliances if these appliances are ordered by the purchaser or retailer before the home enters the first stage of production. These appliances are required to operate from the primary power source, but are not required to operate from a secondary power source.
(2) A visible notification appliance in a room designed for sleeping must have a minimum rating of 177 candela, except that when the visible notification appliance is wall-mounted or suspended more than 24 inches below the ceiling, a minimum rating of 110 candela is permitted.
(3) A visible notification appliance in an area other than a room designed for sleeping must have a minimum rating of 15 candela.
(f) Testing and maintenance. (1) Each required smoke alarm installed at the factory must be operationally tested, after conducting the dielectric test specified in § 3280.810(a), in accordance with the alarm manufacturer's instructions. A smoke alarm that does not function as designed during the test and is not fixed so that it functions properly in the next retest must be replaced. Any replacement smoke alarm must be successfully tested in accordance with this paragraph.
(2) Home manufacturers must provide specific written instructions for installers on how to inspect and test the operation of smoke alarms during installation of the home. These instructions must indicate that any smoke alarm that does not meet the inspection or testing requirements needs to be replaced and retested.
(3) Home manufacturers must provide the homeowner with the alarm manufacturer's information describing the operation, method and frequency of testing, and proper maintenance of the smoke alarm. This information must be provided in same manner and location as the consumer manual required by § 3282.207 of this chapter, but does not have to be incorporated into the consumer manual. No dealer, distributor, construction contractor, or other person shall interfere with the distribution of this information
[67 FR 12817, Mar. 19, 2002, as amended at 67 FR 49795, July 31, 2002. Redesignated at 78 FR 73982, Dec. 9, 2013]
§ 3280.210
Fire testing.
All fire testing conducted in accordance with this subpart shall be performed by nationally recognized testing laboratories which have expertise in fire technology. In case of dispute, the Secretary shall determine if a particular agency is qualified to perform such fire tests.
[49 FR 32011, Aug. 9, 1984. Redesignated at 78 FR 73982, Dec. 9, 2013]

Subpart D—Body and Frame Construction Requirements
§ 3280.301
Scope.
This subpart covers the minimum requirements for materials, products, equipment, and workmanship needed to assure that the manufactured home will provide the following:
(a) Structural strength and rigidity;
(b) Protection against corrosion, decay, insects, rodents, and other similar destructive forces;
(c) Protection against wind hazards;
(d) Resistance to the elements; and
(e) Durability and economy of maintenance.
[78 FR 73982, Dec. 9, 2013]
§ 3280.302
Definitions.
The following definitions are applicable to subpart D only:
Anchor assembly means any device or other means designed to transfer home anchoring loads to the ground.
Anchoring equipment means ties, straps, cables, turnbuckles, chains, and other approved components, including tensioning devices that are used to secure a manufactured home to anchor assemblies.
Anchoring system means a combination of anchoring equipment and anchor assemblies that will, when properly designed and installed, resist the uplift, overturning, and lateral forces on the manufactured home and on its support and foundation system.
Diagonal tie means a tie intended to resist horizontal or shear forces, but which may resist vertical, uplift, and overturning forces.
Footing: means that portion of the support system that transmits loads directly to the soil.
Foundation system means a system of support that is capable of transferring all design loads to the ground, including elements of the support system as defined in this section, or a site-built permanent foundation that meets the requirements of 24 CFR 3282.12.
Ground anchor means a specific anchoring assembly device designed to transfer home anchoring loads to the ground.
Loads: (1) Dead load: means the weight of all permanent construction including walls, floors, roof, partition, and fixed service equipment.
(2) Live load: means the weight superimposed by the use and occupancy of the manufactured home, including wind load and snow load, but not including dead load.
(3) Wind load: means the lateral or vertical pressure or uplift on the manufactured home due to wind blowing in any direction.
Main frame: means the structural component on which is mounted the body of the manufactured home.
Pier: means that portion of the support system between the footing and manufactured home exclusive of caps and shims.
Sheathing: means material which is applied on the exterior side of a building frame under the exterior weather resistant covering.
Stabilizing devices means all components of the anchoring and support systems, such as piers, footings, ties, anchoring equipment, anchoring assemblies, or any other equipment, materials, and methods of construction that support and secure the manufactured home to the ground.
Support system: means a combination of footings, piers, caps, and shims that will, when properly installed, support the manufactured home.
Support system means any pilings, columns, footings, piers, foundation walls, shims, and any combination thereof that, when properly installed, support the manufactured home.
Tie: means straps, cable, or securing devices used to connect the manufactured home to ground anchors.
Vertical tie: means a tie intended to resist the uplifting or overturning forces.
[58 FR 55005, Oct. 25, 1993; 59 FR 15113, Mar. 31, 1994, as amended at 72 FR 59361, Oct. 19, 2007]
§ 3280.303
General requirements.
(a) Minimum requirements. The design and construction of a manufactured home shall conform with the provisions of this standard. Requirements for any size, weight, or quality of material modified by the terms of minimum, not less than, at least, and similar expressions are minimum standards. The manufacturer or installer may exceed these standards provided such deviation does not result in any inferior installation or defeat the purpose and intent of this standard.
(b) Construction. All construction methods shall be in conformance with accepted engineering practices to insure durable, livable, and safe housing and shall demonstrate acceptable workmanship reflecting journeyman quality of work of the various trades.
(c) Structural analysis. The strength and rigidity of the component parts and/or the integrated structure shall be determined by engineering analysis or by suitable load tests to simulate the actual loads and conditions of application that occur. (See subparts E and J.)
(d) [Reserved]
(e) New materials and methods. (1) Any new material or method of construction not provided for in this standard and any material or method of questioned suitability proposed for use in the manufacture of the structure shall nevertheless conform in performance to the requirements of this standard.
(2) Unless based on accepted engineering design for the use indicated, all new manufactured home materials, equipment, systems or methods of construction not provided for in this standard shall be subjected to the tests specified in paragraph (g) of this section.
(f) Allowable design stress. The design stresses of all materials shall conform to accepted engineering practice. The use of materials not certified as to strength or stress grade shall be limited to the minimum allowable stresses under accepted engineering practice.
(g) Alternative test procedures. In the absence of recognized testing procedures either in the Standards in this part or in the applicable provisions of those standards incorporated in this part by reference, the manufacturer electing this option must develop or cause to be developed testing procedures to demonstrate the structural properties and significant characteristics of the material, assembly, subassembly component, or member, except for testing methods involving one-piece metal roofing as would be required in § 3280.305(c)(1)(iii). Such testing procedures become part of the manufacturer's approved design. Such tests must be witnessed by an independent licensed professional engineer or architect or by a recognized testing organization. Copies of the test results must be kept on file by the manufactured home manufacturer.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55005, Oct. 25, 1993; 59 FR 2469, Jan. 14, 1994; 70 FR 72043, Nov. 30, 2005]
§ 3280.304
Materials.
(a) Dimension and board lumber shall not exceed 19 percent moisture content at time of installation.
(b)(1) Standards for some of the generally used materials and methods of construction are listed in the following table:

Aluminum
Aluminum Design Manual, Specifications and Guidelines for Aluminum Structures, Part 1-A, Sixth Edition, October 1994, and Part 1-B, First Edition, October 1994.

Steel
Specification for Structural Steel Buildings—Allowable Stress Design and Plastic Design—AISC-S335, 1989. The following parts of this reference standard are not applicable: 1.3.3, 1.3.4, 1.3.5, 1.3.6, 1.4.6, 1.5.1.5, 1.5.5, 1.6, 1.7, 1.8, 1.9, 1.10.4 through 1.10.7, 1.10.9, 1.11, 1.13, 1.14.5, 1.17.7 through 1.17.9, 1.19.1, 1.19.3, 1.20, 1.21, 1.23.7, 1.24, 1.25.1 through 1.25.5, 1.26.4, 2.3, 2.4, 2.8 through 2.10.
Specification for the Design of Cold-Formed Steel Structural Members—AISI-1996.
Specification for the Design of Cold-Formed Stainless Steel Structural Members—SEI/ASCE 8-02, 2002.
Standard Specifications Load Tables and Weight Tables for Steel Joists and Joist Girders, SJI, Fortieth Edition, 1994.
Structural Applications of Steel Cables for Buildings—ASCE19, 1996.
Standard Specification for Strapping, Flat Steel and Seals—ASTM D3953, 1991.

Wood and Wood Products
Basic Hardboard—ANSI/AHA A135.4-1995.
Prefinished Hardboard Paneling—ANSI/AHA A135.5-1995.
Hardboard Siding—ANSI/AHA A135.6-1998.
American National Standard for Hardwood and Decorative Plywood—ANSI/HPVA HP-1-1994 (Approved 1995).
Structural Design Guide for Hardwood Plywood Wall Panels—HPVA Design Guide HP-SG-96, 1996.
For wood products—Structural Glued Laminated Timber—ANSI/AITC A190.1-1992.
Construction and Industrial Plywood (With Typical APA Trademarks)—PS 1-95.
APA Design/Construction Guide, Residential and Commercial—APA E30-P-1996.
Design Specifications for Metal Plate and Wood Connected Trusses—TPI-85.
Design and Fabrication of All-Plywood Beams—APA H-815E (PDS Supplement #5), 1995.
Panel Design Specification—APA D410A, 2004.
Design and Fabrication of Glued Plywood-Lumber Beams, Supplement# 2—APA S 812R, 1992 (incorporated by reference, see § 3280.4).
Design and Fabrication of Plywood Curved Panels—APA-S 811M, Suppl. 1, 1990.
Design and Fabrication of Plywood Sandwich Panels, Supplement #4—APA U 814H, 1990 (incorporated by reference, see § 3280.4).
Performance Standard for Wood-Based Structural Use Panels—NIST PS 2-04, 2004 (incorporated by reference, see § 3280.4).
Design and Fabrication of Plywood Stressed-Skin Panels, Supplement 3—APA-U 813L, 1992 (incorporated by reference, see § 3280.4).
National Design Specifications for Wood Construction, 2001 Edition, with Supplement, Design Values for Wood Construction, NDS-2001, ANSI/AFPA.
Wood Structural Design Data, 1986 Edition with 1992 Revisions, AFPA.
Span Tables for Joists and Rafters—PS-20-70, 1993, AFPA.
Design Values for Joists and Rafters 1992, AFPA.
Particleboard—ANSI A208.1-1999.
Voluntary Specifications for Aluminum, Vinyl (PVC) and Wood Windows and Glass Doors—ANSI/AAMA/NWWDA 101/I.S.2-97.
Standard Test Methods for Puncture and Stiffness of Paperboard, and Corrugated and Solid Fiberboard—ASTM D781, 1973.
Standard Test Methods for Direct Moisture Content Measurement of Wood and Wood-Base Materials—ASTM D 4442-92 (Re-approved 1997), 1997.
Standard Test Methods for Use and Calibration of Hand-Held Moisture Meters—ASTM D4444, 1992.
Engineered Wood Construction Guide—APA E30R 2001 (incorporated by reference, see § 3280.4).
Medium Density Fiberboard (MDF) For Interior Applications—ANSI A208.2-2002 (incorporated by reference, see § 3280.4).

Other
Standard Specification for Gypsum Wallboard—ASTM C 36/C 36M-99, 1999.

Fasteners
National Evaluation Report, Power Driven Staples, Nails, and Allied Fasteners for Use in All Types of Building Construction—NER-272, 1997.

Unclassified
Minimum Design Loads for Buildings and Other Structures—ASCE 7-1988.
Standard for Safety Glazing Materials used in Buildings—Safety Performance Specifications and Methods of Test, ANSI Z97.1-2004 (incorporated by reference, see § 3280.4).
(2) Materials and methods of construction utilized in the design and construction of manufactured homes which are covered by the standards in the following table, or any applicable portion thereof shall comply with these requirements.
(3) Engineering analysis and testing methods contained in these references shall be utilized to judge conformance with accepted engineering practices required in § 3280.303(c).
(4) Materials and methods of installation conforming to these standards shall be considered acceptable when installed in conformance with the requirements of this part.
(5) Materials meeting the standards (or the applicable portion thereof) are considered acceptable unless otherwise specified herein or unless substantial doubt exists as to conformance.
(c) Wood products shall be identified as complying with the appropriate standards.
[40 FR 58752, Dec. 18, 1975, as amended at 42 FR 961, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55006, Oct. 25, 1993; 59 FR 15113, Mar. 31, 1994; 70 FR 72043, Nov. 30, 2005; 78 FR 73982, Dec. 9, 2013]
§ 3280.305
Structural design requirements.
(a) General. Each manufactured home shall be designed and constructed as a completely integrated structure capable of sustaining the design load requirements of this standard, and shall be capable of transmitting these loads to stabilizing devices without exceeding the allowable stresses or deflections. Roof framing shall be securely fastened to wall framing, walls to floor structure, and floor structure to chassis to secure and maintain continuity between the floor and chassis, so as to resist wind overturning, uplift, and sliding as imposed by design loads in this part. Uncompressed finished flooring greater than 1/8 inch in thickness shall not extend beneath load-bearing walls that are fastened to the floor structure.
(b) Design loads—(1) Design dead loads. Design dead loads shall be the actual dead load supported by the structural assembly under consideration.
(2) Design live loads. The design live loads and wind and snow loads shall be as specified in this section and shall be considered to be uniformly distributed. The roof live load or snow load shall not be considered as acting simultaneously with the wind load and the roof live or snow load and floor live loads shall not be considered as resisting the overturning moment due to wind.
(3) When engineering calculations are performed, allowable unit stresses may be increased as provided in the documents referenced in § 3280.304 except as otherwise indicated in §§ 3280.304(b)(1) and 3280.306(a).
(4) Whenever the roof slope does not exceed 20 degrees, the design horizontal wind loads required by § 3280.305(c)(1) may be determined without including the vertical roof projection of the manufactured home. However, regardless of the roof slope of the manufactured home, the vertical roof projection shall be included when determining the wind loading for split level or clerestory-type roof systems.
(c) Wind, snow, and roof loads—(1) Wind loads—design requirements. (i) Standard wind loads (Zone I). When a manufactured home is not designed to resist the wind loads for high-wind areas (Zone II or Zone III) specified in paragraph (c)(1)(ii) of this section, the manufactured home and each of its wind-resisting parts and portions must be designed for horizontal wind loads of not less than 15 psf and a net uplift roof load of not less than 9 psf. The net uplift roof load must not be reduced by the dead load of the roof structure for the purposes of engineering design or structural load testing.
(ii) Wind loads for high wind areas (Zone II and Zone III). When designed for high wind areas (Zone II and Zone III), the manufactured home, each of its wind resisting parts (including, but not limited to, shear walls, diaphragms, ridge beams, and their fastening and anchoring systems), and its components and cladding materials (including, but not limited to, roof trusses, wall studs, exterior sheathing, roofing and siding materials, exterior glazing, and their connections and fasteners) shall be designed by a Professional Engineer or Architect to resist:
(A) The design wind loads for Exposure C specified in ANSI/ASCE 7-88, “Minimum Design Loads for Buildings and Other Structures,” for a fifty-year recurrence interval, and a design wind speed of 100 mph, as specified for Wind Zone II, or 110 mph, as specified for Wind Zone III (Basic Wind Zone Map); or
(B) The wind pressures specified in the following table:
Table of Design Wind Pressures
Element | Wind zone II design wind speed 100 MPH | Wind zone III design wind speed 110 MPH
Anchorage for lateral and vertical stability (See § 3280.306(a)):
Net Horizontal Drag ^{1 2}: | ^3 ±39 PSF | ^3 ±47 PSF
Uplift ^4: | ^5 −27 PSF | −32 PSF
Main wind force resisting system:
Shearwalls, Diaphragms and their Fastening and Anchorage Systems ^{1 2} | ±39 PSF | ±47 PSF
Ridge beams and other Main Roof Support Beams (Beams supporting expanding room sections, etc.) | −30 PSF | −36 PSF
Components and cladding:
Roof trusses ^4 in all areas; trusses shall be doubled within 3′-0′ from each end of the roof | ^5 −39 PSF | ^5 −47 PSF
Exterior roof coverings, sheathing and fastenings ^4,^6,^7 in all areas except the following | ^5 −39 PSF | ^5 −47 PSF
Within 3′-0′ from each gable end (overhang at end wall) of the roof or endwall if no overhang is provided ^4,^6,^7 | ^5 −73 PSF | ^5 −89 PSF
Within 3′-0′ from the ridge and eave (overhang at sidewall) or sidewall if no eave is provided ^4,^6,^7 | ^5 −51 PSF | ^5 −62 PSF
Eaves (Overhangs at Sidewalls) ^4,^6,^7 | ^5 −51 PSF | ^5 −62 PSF
Gables (Overhangs at Endwalls) ^4,^6,^7 | ^5 −73 PSF | ^5 −89 PSF
Wall studs in sidewalls and endwalls, exterior windows and sliding glass doors (glazing and framing), exterior coverings, sheathing and fastenings ^8:
Within 3′-0′ from each corner of the sidewall and endwall | ±48 PSF | ±58 PSF
All other areas | ±38 PSF | ±46 PSF
NOTES:
^1 The net horizontal drag of ±39 PSF to be used in calculating Anchorage for Lateral and Vertical Stability and for the design of Main Wind Force Resisting Systems is based on a distribution of wind pressures of + 0.8 or + 24 PSF to the windward wall and −0.5 or −15 PSF to the leeward wall.
^2 Horizontal drag pressures need not be applied to roof projections when the roof slope does not exceed 20 degrees.
^3 + sign would mean pressures are acting towards or on the structure; − sign means pressures are acting away from the structure; ±sign means forces can act in either direction, towards or away from the structure.
^4 Design values in this “Table” are only applicable to roof slopes between 10 degrees (nominal 2/12 slope) and 30 degrees.
^5 The design uplift pressures are the same whether they are applied normal to the surface of the roof or to the horizontal projection of the roof.
^6 Shingle roof coverings that are secured with 6 fasteners per shingle through an underlayment which is cemented to a 3/8” structural rated roof sheathing need not be evaluated for these design wind pressures.
^7 Structural rated roof sheathing that is at least 3/8” in thickness, installed with the long dimension perpendicular to roof framing supports, and secured with fasteners at 4” on center within 3′-0′ of each gable end or endwall if no overhang is provided and 6” on center in all other areas, need not be evaluated for these design wind pressures.
^8 Exterior coverings that are secured at 6″ o.c. to a 3/8″ structural rated sheathing that is fastened to wall framing members at 6″ on center need not be evaluated for these design wind pressures.
(iii) One-piece metal roofing capable of resisting the design wind pressures for “Components and Cladding: (Exterior roof coverings)” in the Table for Design Wind Pressures in this section is allowed to be used without structural sheathing, provided the metal roofing is tested using procedures that have been approved by HUD and that meet all requirements of §§ 3280.303(c) and (g) and 3280.401.
(2) Wind loads—zone designations. The Wind Zone and specific wind design load requirements are determined by the fastest basic wind speed (mph) within each Zone and the intended location, based on the Basic Wind Zone Map, as follows:
(i) Wind Zone I. Wind Zone I consists of those areas on the Basic Wind Zone Map that are not identified in paragraphs (c)(2)(ii) or (iii) of this section as being within Wind Zone II or III, respectively.
(ii) Wind Zone II.....100 mph. The following areas are deemed to be within Wind Zone II of the Basic Wind Zone Map:
Local governments: The following local governments listed by State (counties, unless specified otherwise):
Alabama: Baldwin and Mobile.
Florida: All counties except those identified in paragraph (c)(1)(i)(C) of this section as within Wind Zone III.
Georgia: Bryan, Camden, Chatham, Glynn, Liberty, McIntosh.
Louisiana: Parishes of Acadia, Allen, Ascension, Assumption, Calcasieu, Cameron, East Baton Rouge, East Feliciana, Evangeline, Iberia, Iberville, Jefferson Davis, LaFayette, Livingston, Pointe Coupee, St. Helena, St. James, St. John the Baptist, St. Landry, St. Martin, St. Tammany, Tangipahoa, Vermillion, Washington, West Baton Rouge, and West Feliciana.
Maine: Hancock and Washington.
Massachusetts: Barnstable, Bristol, Dukes, Nantucket, and Plymouth.
Mississippi: George, Hancock, Harrison, Jackson, Pearl River, and Stone.
North Carolina: Beaufort, Brunswick, Camden, Chowan, Columbus, Craven, Currituck, Jones, New Hanover, Onslow, Pamlico, Pasquotank, Pender, Perquimans, Tyrrell, and Washington.
South Carolina: Beaufort, Berkeley, Charleston, Colleton, Dorchester, Georgetown, Horry, Jasper, and Williamsburg.
Texas: Aransas, Brazoria, Calhoun, Cameron, Chambers, Galveston, Jefferson, Kenedy, Kleberg, Matagorda, Nueces, Orange, Refugio, San Patricio, and Willacy.
Virginia: Cities of Chesapeake, Norfolk, Portsmouth, Princess Anne, and Virginia Beach.
(iii) Wind Zone III.....110 mph. The following areas are considered to be within Wind Zone III of the Basic Wind Zone Map:
(A) States and Territories: The entire State of Hawaii, the coastal regions of Alaska (as determined by the 90 mph isotach on the ANSI/ASCE 7-88 map), and all of the U.S. Territories of American Samoa, Guam, Northern Mariana Islands, Puerto Rico, Trust Territory of the Pacific Islands, and the United States Virgin Islands.
(B) Local governments: The following local governments listed by State (counties, unless specified otherwise):
Florida: Broward, Charlotte, Collier, Dade, Franklin, Gulf, Hendry, Lee, Martin, Manatee, Monroe, Palm Beach, Pinellas, and Sarasota.
Louisiana: Parishes of Jefferson, La Fourche, Orleans, Plaquemines, St. Bernard, St. Charles, St. Mary, and Terrabonne.
North Carolina: Carteret, Dare, and Hyde.
(iv) Consideration of local requirements. For areas where wind mapping data or records or the requirements of the State or local authority indicate wind speeds in excess of those identified in this section, the Department may establish, through rulemaking, more stringent requirements for manufactured homes to be installed in such areas.
(3) Snow and roof loads. (i) Flat, curved and pitched roofs shall be designed to resist the following live loads, applied downward on the horizontal projection as appropriate for the design zone marked on the manufactured home:
Zone (see Map in § 3280.305(c)(4)) | Pounds per square foot
North Zone | 40
Middle Zone | 30
South Zone | 20
(A) North Roof Load Zone. The following counties in each of the following states are deemed to be within the North Roof Load Zone:
Maine—Aroostook, Piscataquis, Somerset, Penobscot, Waldo, Knox, Hancock, and Washington.
Alaska—All Counties
(B) Middle Roof Load Zone. The following counties in each of the following states are deemed to be within the Middle Roof Load Zone:
States | Counties | | |
South Dakota | Grant | Brookings | Hanson | Lincoln
| Codington | Miner | Minnehaha | Yankton
| Deuel | Lake | Hutchinson | Union
| Hamlin | Moody | Turner | Clay
| Kingsbury | McCook
Minnesota | Koochiching | Stearns | Renville | Sibley
| Itasca | Swift | McLeod | Nicollet
| Hubbard | Kandiyohi | Carver | Blue Earth
| Cass | Meeker | Dakota | Martin
| Crow Wing | Wright | Goodhue | Watonwan
| Aitkin | Lac qui Parle | Wabasha | Brown
| St. Louis | Chippewa | Winona | Redwood
| Lake | Yellow Medicine | Fillmore | Lyon
| Cook | Mille Lacs | Mower | Lincoln
| | Carlton | Kanabec | Olmsted | Pipestone
| Pine | Benton | Dodge | Murray
| Wadena | Isanti | Rice | Cottonwood
| Todd | Sherburne | Steele | Jackson
| Morrison | Anoka | Freeborn | Nobles
| Douglas | Chisapo | Faribault | Rock
| Grant | Washington | Waseca
| Stevens | Hennepin | Le Sueur
| Pope | Ramsey | Scott
Iowa | Hancock | Mitchell | Hamilton | Buena Vista
| Lyon | Howard | Webster | Cherokee
| Osceola | Chickasaw | Calhoun | Plymouth
| Dickinson | Butler | Sac | Sioux
| Emmet | Floyd | Ida | O'Brien
| Kossuth | Cerro Gordo | Humboldt | Clay
| Winnebago | Franklin | Pocahontas | Wright
| Worth | Hardin | Palo Alto
Wisconsin | Douglas | Oconto | Pepin | Lincoln
| Bayfield | Menominee | Pierce | Oneida
| Ashland | Langlade | Dunn | Polk
| Iron | Marathon | Eau Claire | Burnett
| Vilas | Clark | Chippewa | Washburn
| Forest | Jackson | Rusk | Sawyer
| Florence | Trempealeau | Barron | Price
| Marinette | Buffalo | Taylor | Door
| St. Croix
Michigan | Houghton | Iron | Presque Isle | Wexford
| Baraga | Dickinson | Charlevoix | Benzie
| Marquette | Menominee | Montmorency | Grand Traverse
| Alger | Delta | Alpena | Kalkaska
| Luce | Schoolcraft | Alcona | Oscoda
| Chippewa | Mackinac | Ogemaw | Otsego
| Keweenaw | Cheyboygan | Roscommon | Leelanau
| Ontonagon | Emmet | Missaukee | Antrim
| Gogebic | Crawford
New York | St. Lawrence | Herkimer | Onondaga | Genesee
| Franklin | Lewis | Madison | Orleans
| Clinton | Oswego | Cayuga | Niagara
| Essex | Jefferson | Seneca | Erie
| Hamilton | Oneida | Wayne | Wyoming
| Warren | Fulton | Ontario | Monroe
| Saratoga | Montgomery | Yates
| Washington | Schenectady | Livingston
Massachusetts | Essex
Maine | Franklin | Kennebec | Lincoln | Cumberland
| Oxford | Androscoggin | Sagadahoc | York
Montana | All Counties
Idaho | All Counties
Colorado | All Counties
Wyoming | All Counties
Utah | All Counties
Vermont | Franklin | Orleans | Caledonia | Addison
| Grand Isle | Essex | Washington | Rutland
| Lamoille | Chittenden | Orange | Windsor
New Hampshire | All Counties
(C) South Roof Load Zone. The states and counties that are not listed for the North Roof Load Zone in paragraph (c)(3)(i)(A) of this section, or the Middle Roof Load Zone in paragraph (c)(3)(i)(B) of this section, are deemed to be within the South Roof Load Zone.
(ii) Consideration of local requirements. For exposures in areas (mountainous or other) where recognized snow records, wind records, or the requirements of the State or local authority indicate significant differences from the loads stated in this paragraph (c)(3), the Department may establish, through rulemaking, more stringent requirements for manufactured homes to be installed in such areas. For snow loads, such requirements must be based on a roof snow load of 0.6 of the ground snow load for areas exposed to wind and a roof snow load of 0.8 of the ground snow load for sheltered areas.
(iii) Eaves and cornices shall be designed for a net uplift pressure of 2.5 times the design uplift wind pressure cited in § 3280.305(c)(1)(i) for Wind Zone I, and for the design pressures cited in § 3280.305(c)(1)(ii) for Wind Zones II and III.
(iv) Skylights must be capable of withstanding roof loads as specified in paragraphs (c)(3)(i) or (c)(3)(ii) of this section. Skylights must be listed and tested in accordance with AAMA 1600/I.S.7-00, 2003, Voluntary Specification for Skylights.
(4) Data plate requirements. The Data Plate posted in the manufactured home (see § 3280.5) shall designate the wind and roof load zones or, if designed for higher loads, the actual design external snow and wind loads for which the home has been designed. The Data Plate shall include reproductions of the Load Zone Maps shown in this paragraph (c)(4), with any related information. The Load Zone Maps shall be not less than either 31/2 in. by 21/4 in., or one-half the size illustrated in the Code of Federal Regulations.
(d) Design load deflection. (1) When a structural assembly is subjected to total design live loads, the deflection for structural framing members shall not exceed the following (where L equals the clear span between supports or two times the length of a cantilever):
Floor—L/240
Roof and ceiling—L/180
Headers, beams, and girders (vertical load)—L/180
Walls and partitions—L/180
(2) The allowable eave or cornice deflection for uplift is to be measured at the design uplift load of 9 psf for Wind Zone I, and at the design uplift pressure cited in paragraph (c)(1)(ii) of this section for Wind Zones II and III. The allowable deflection shall be (2 × Lc)/180, where Lc is the measured horizontal eave projection from the wall.
(e) Fastening of structural systems. (1) Roof framing must be securely fastened to wall framing, walls to floor structure, and floor structure to chassis, to secure and maintain continuity between the floor and chassis in order to resist wind overturning, uplift, and sliding, and to provide continuous load paths for these forces to the foundation or anchorage system. The number and type of fasteners used must be capable of transferring all forces between elements being joined.
(2) For Wind Zone II and Wind Zone III, roof framing members must be securely fastened at the vertical bearing points to resist design overturning, uplift, and sliding forces. When engineered connectors are not installed, roof framing members must be secured at the vertical bearing points to wall framing members (studs), and wall framing members (studs) must be secured to floor framing members, with 0.016 inch base metal, minimum steel strapping or engineered connectors, or by a combination of 0.016 inch base metal, minimum steel strapping or engineered connectors, and structural-rated wall sheathing that overlaps the roof and floor system if substantiated by structural analysis or by suitable load tests. Steel strapping or engineered connectors are to be installed at a maximum spacing of 24 inches on center in Wind Zone II, and 16 inches on center in Wind Zone III. Exception: Where substantiated by structural analysis or suitable load tests, the 0.016 inch base metal minimum steel strapping or engineered connectors may be omitted at the roof to wall and/or wall to floor connections, when structural rated sheathing that overlaps the roof and wall and/or wall and floor is capable of resisting the applicable design wind loads.
(f) Walls. The walls shall be of sufficient strength to withstand the load requirements as defined in § 3280.305(c) of this part, without exceeding the deflections as specified in § 3280.305(d). The connections between the bearing walls, floor, and roof framework members shall be fabricated in such a manner as to provide support for the material used to enclose the manufactured home and to provide for transfer of all lateral and vertical loads to the floor and chassis.
(1) Except where substantiated by engineering analysis or tests, studs shall not be notched or drilled in the middle one-third of their length.
(2) Interior walls and partitions shall be constructed with structural capacity adequate for the intended purpose and shall be capable of resisting a horizontal load of not less than five pounds per square foot. An allowable stress increase of 1.33 times the permitted published design values may be used in the design of wood framed interior partitions. Finish of walls and partitions shall be securely fastened to wall framing.
(g) Floors. (1) Floor assemblies shall be designed in accordance with accepted engineering practice standards to support a minimum uniform live load of 40 lb/ft ^2 plus the dead load of the materials. In addition (but not simultaneously), floors shall be able to support a 200-pound concentrated load on a one-inch diameter disc at the most critical location with a maximum deflection not to exceed one-eighth inch relative to floor framing. Perimeter wood joists of more than six inches depth shall be stabilized against overturning from superimposed loads as follows: at ends by solid blocking not less than two-inch thickness by full depth of joist, or by connecting to a continuous header not less than two-inch thickness and not less than the depth of the joist with connecting devices; at eight-feet maximum intermediate spacing by solid blocking or by wood cross-bridging of not less than one inch by three inches, metal cross-bridging of equal strength, or by other approved methods.
(2) Wood, wood fiber or plywood floors or subfloors in kitchens, bathrooms (including toilet compartments), laundry areas, water heater compartments, and any other areas subject to excessive moisture shall be moisture resistant or shall be made moisture resistant by sealing or by an overlay of nonabsorbent material applied with water-resistant adhesive. Use of one of the following methods would meet this requirement:
(i) Sealing the floor with a water-resistant sealer; or
(ii) Installing an overlay of a non-absorbent floor covering material applied with water-resistant adhesive; or
(iii) Direct application of a water-resistant sealer to the exposed wood floor area when covered with a non-absorbent overlay; or
(iv) The use of a non-absorbent floor covering which may be installed without a continuous application of a water-resistant adhesive or sealant when the floor covering meets the following criteria:
(A) The covering is a continuous membrane with any seams or patches seam bonded or welded to preserve the continuity of the floor covering; and
(B) The floor is protected at all penetrations in these areas by sealing with a compatible water-resistant adhesive or sealant to prevent moisture from migrating under the nonabsorbent floor covering; and
(C) The covering is fastened around the perimeter of the subfloor in accordance with the floor covering manufacturer's instructions; and,
(D) The covering is designed to be installed to prevent moisture penetration without the use of a water-resistant adhesive or sealer except as required in this paragraph (g). The vertical edges of penetrations for plumbing shall be covered with a moisture-resistant adhesive or sealant. The vertical penetrations located under the bottom plates of perimeter walls of rooms, areas, or compartments are not required to be sealed; this does not include walls or partitions within the rooms or areas.
(3) Wood panel products used as floor or subfloor materials on the exterior of the home, such as in recessed entryways, must be rated for exterior exposure and protected from moisture by sealing or applying nonabsorbent overlay with water resistant adhesive.
(4) Carpet or carpet pads shall not be installed under concealed spaces subject to excessive moisture, such as plumbing fixture spaces, floor areas under installed laundry equipment. Carpet may be installed in laundry space provided:
(i) The appliances are not provided;
(ii) The conditions of paragraph (g)(2) of this section are followed; and
(iii) Instructions are provided to remove carpet when appliances are installed.
(5) Except where substantiated by engineering analysis or tests:
(i) Notches on the ends of joists shall not exceed one-fourth the joist depth.
(ii) Holes bored in joists shall not be within 2 inches of the top or bottom of the joist, and the diameter of any such hole shall not exceed one-third the depth of the joist.
(iii) Notches in the top or bottom of the joists shall not exceed one-sixth the depth and shall not be located in the middle third of the span.
(6) Bottom board material (with or without patches) shall meet or exceed the level of 48 inch-pounds of puncture resistance as tested by the Beach Puncture Test in accordance with Standard Test Methods for Puncture and Stiffness of Paperboard, and Corrugated and Solid Fiberboard, ASTM D-781-1968 (73). The material shall be suitable for patches and the patch life shall be equivalent to the material life. Patch installation instruction shall be included in the manufactured home manufacturer's instructions.
(h) Roofs. (1) Roofs shall be of sufficient strength to withstand the load requirements as defined in § 3280.305 (b) and (c) without exceeding the deflections specified in § 3280.305(d). The connections between roof framework members and bearing walls shall be fabricated in such a manner to provide for the transfer of design vertical and horizontal loads to the bearing walls and to resist uplift forces.
(2) Roofing membranes shall be of sufficient rigidity to prevent deflection which would permit ponding of water or separation of seams due to wind, snow, ice, erection or transportation forces.
(3) Cutting of roof framework members for passage of electrical, plumbing or mechanical systems shall not be allowed except where substantiated by engineering analysis.
(4) All roof penetrations for electrical, plumbing or mechanical systems shall be properly flashed and sealed. In addition, where a metal roof membrane is penetrated, a wood backer shall be installed. The backer plate shall be not less than 5/16 inch plywood, with exterior glues, secured to the roof framing system beneath the metal roof, and shall be of a size to assure that all screws securing the flashing are held by the backer plate.
(i) Frame construction. The frame shall be capable of transmitting all design loads to stabilizing devices without exceeding the allowable load and deflections of this section. The frame shall also be capable of withstanding the effects of transportation shock and vibration without degradation as required by subpart J.
(1) [Reserved]
(2) Protection of metal frames against corrosion. Metal frames shall be made corrosion resistant or protected against corrosion. Metal frames may be protected against corrosion by painting.
(j) Welded connections. (1) All welds must be made in accordance with the applicable provisions of the Specification for Structural Steel Buildings, Allowable Stress Design and Plastic Design, AISC-S335, 1989; the Specification for the Design of Cold-Formed Steel Structural Members, AISI, 1996; and the Specification for the Design of Cold-Formed Stainless Steel Structural Members, SEI/ASCE 8-02, 2002.
(2) Regardless of the provisions of any reference standard contained in this subpart, deposits of weld slag or flux shall be required to be removed only from welded joints at the following locations:
(i) Drawbar and coupling mechanisms;
(ii) Main member splices, and
(iii) Spring hanger to main member connections.
(k) Attics. (1) For roofs with slopes 7:12 or greater, the area of the attic floor that meets the ceiling-height/living-space requirements of these construction and safety standards must be designed to resist a minimum design live load of 40 pounds per square foot (psf) in accordance with paragraph (g) of this section.
(2) For roofs with slopes less than 7:12 that contain an attic area or for portions of roofs with slopes 7:12 or greater that do meet the ceiling height/living space requirements of the standards, the attic floor must be designed for a storage live load of 20 pounds per square foot (psf).
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 44 FR 66195, Nov. 19, 1979; 52 FR 4582, Feb. 12, 1987; 58 FR 55006, Oct. 25, 1993; 59 FR 2469, Jan. 14, 1994; 59 FR 15113, 15114, Mar. 31, 1994; 62 FR 54547, Oct. 20, 1997; 70 FR 72043, Nov. 30, 2005; 71 FR 19638, Apr. 17, 2006; 78 FR 73983, Dec. 9, 2013; 80 FR 53727, Sept. 8, 2015]
§ 3280.306
Windstorm protection.
(a) Provisions for support and anchoring systems. Each manufactured home shall have provisions for support/anchoring or foundation systems that, when properly designed and installed, will resist overturning and lateral movement (sliding) of the manufactured home as imposed by the respective design loads. For Wind Zone I, the design wind loads to be used for calculating resistance to overturning and lateral movement shall be the simultaneous application of the wind loads indicated in § 3280.305(c)(1)(i), increased by a factor of 1.5. The 1.5 factor of safety for Wind Zone I is also to be applied simultaneously to both the vertical building projection, as horizontal wind load, and across the surface of the full roof structure, as uplift loading. For Wind Zones II and III, the resistance shall be determined by the simultaneous application of the horizontal drag and uplift wind loads, in accordance with § 3280.305(c)(1)(ii). The basic allowable stresses of materials required to resist overturning and lateral movement shall not be increased in the design and proportioning of these members. No additional shape or location factors need to be applied in the design of the tiedown system. The dead load of the structure may be used to resist these wind loading effects in all Wind Zones.
(1) The provisions of this section shall be followed and the support and anchoring systems shall be designed by a Registered Professional Engineer or Architect.
(2) The manufacturer of each manufactured home is required to make provision for the support and anchoring systems but is not required to provide the anchoring equipment or stabilizing devices. When the manufacturer's installation instructions provide for the main frame structure to be used as the points for connection of diagonal ties, no specific connecting devices need be provided on the main frame structure.
(b) Contents of instructions. (1) The manufacturer must provide printed instructions with each manufactured home that specify the location and required capacity of stabilizing devices on which the home's design is based. The manufacturer must identify by paint, label, decal stencil, or other means: the location of each column support pier location required along the marriage line(s) of multi-section manufactured homes; each pier location required along the perimeter of the home; each required shear wall pier support; and any other special pier support locations specified in the manufacturer's printed instructions. Such identifications must be visible after the home is installed. The manufacturer must provide drawings and specifications, certified by a registered professional engineer or architect, that indicate at least one acceptable system of anchoring, including the details or required straps or cables, their end connections, and all other devices needed to transfer the wind loads from the manufactured home to an anchoring or foundation system.
(2) For anchoring systems, the instructions shall indicate:
(i) The minimum anchor capacity required;
(ii) That anchors should be certified by a professional engineer, architect, or a nationally recognized testing laboratory as to their resistance, based on the maximum angle of diagonal tie and/or vertical tie loading (see paragraph (c)(3) of this section) and angle of anchor installation, and type of soil in which the anchor is to be installed;
(iii) That ground anchors are to be embedded below the frost line, unless the foundation system is frost-protected in accordance with §§ 3285.312(b) and 3285.404 of the Model Manufactured Home Installation Standards in this chapter.
(iv) That ground anchors must be installed to their full depth, and stabilizer plates must be installed in accordance with the ground anchor listing or certification to provide required resistance to overturning and sliding.
(v) That anchoring equipment should be certified by a registered professional engineer or architect to resist these specified forces in accordance with testing procedures in ASTM D3953-97, Standard Specification for Strapping, Flat Steel and Seals (incorporated by reference, see § 3280.4).
(c) Design criteria. The provisions made for anchoring systems shall be based on the following design criteria for manufactured homes.
(1) The minimum number of ties provided per side of each home shall resist design wind loads required in § 3280.305(c)(1).
(2) Ties shall be as evenly spaced as practicable along the length of the manufactured home, with not more than two (2) feet open-end spacing on each end.
(3) Vertical ties or straps shall be positioned at studs. Where a vertical tie and a diagonal tie are located at the same place, both ties may be connected to a single anchor, provided that the anchor used is capable of carrying both loadings, simultaneously.
(4) Add-on sections of expandable manufactured homes shall have provisions for vertical ties at the exposed ends.
(d) Requirements for ties. Manufactured homes in Wind Zone I require only diagonal ties. These ties shall be placed along the main frame and below the outer side walls. All manufactured homes designed to be located in Wind Zones II and III shall have a vertical tie installed at each diagonal tie location.
(e) Protection requirements. Protection shall be provided at sharp corners where the anchoring system requires the use of external straps or cables. Protection shall also be provided to minimize damage to siding by the cable or strap.
(f) Anchoring equipment—load resistance. Anchoring equipment shall be capable of resisting an allowable working load equal to or exceeding 3,150 pounds and shall be capable of withstanding a 50 percent overload (4,725 pounds total) without failure of either the anchoring equipment or the attachment point on the manufactured home.
(g) Anchoring equipment—weatherization. Anchoring equipment exposed to weathering shall have a resistance to weather deterioration at least equivalent to that provided by a coating of zinc on steel of not less than 0.30 ounces per square foot of surface coated, and in accordance with the following:
(1) Slit or cut edges of zinc-coated steel strapping do not need to be zinc coated.
(2) Type 1, Finish B, Grade 1 steel strapping, 11/4 inches wide and 0.035 inches in thickness, certified by a registered professional engineer or architect as conforming with ASTM D3953-97, Standard Specification for Strapping, Flat Steel and Seals (incorporated by reference, see § 3280.4).
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4583, Feb. 12, 1987; 59 FR 2473, Jan. 14, 1994; 70 FR 72045, Nov. 30, 2005; 72 FR 59362, Oct. 19, 2007; 78 FR 73983, Dec. 9, 2013]
§ 3280.307
Resistance to elements and use.
(a) Exterior coverings shall be of moisture and weather resistive materials attached with corrosion resistant fasteners to resist wind, snow and rain. Metal coverings and exposed metal structural members shall be of corrosion resistant materials or shall be protected to resist corrosion. All joints between portions of the exterior covering shall be designed, and assembled to protect against the infiltration of air and water, except for any designed ventilation of wall or roof cavity.
(b) Joints between dissimilar materials and joints between exterior coverings and frames of openings shall be protected with a compatible sealant suitable to resist infiltration of air or water.
(c) Where adjoining materials or assemblies of materials are of such nature that separation can occur due to expansion, contraction, wind loads or other loads induced by erection or transportation, sealants shall be of a type that maintains protection against infiltration or penetration by air, moisture or vermin.
(d) Exterior surfaces shall be sealed to resist the entrance of rodents.
§ 3280.308
Formaldehyde emission controls for certain wood products.
(a) Formaldehyde emission levels. All plywood and particleboard materials bonded with a resin system or coated with a surface finish containing formaldehyde shall not exceed the following formaldehyde emission levels when installed in manufactured homes:
(1) Plywood materials shall not emit formaldehyde in excess of 0.2 parts per million (ppm) as measured by the air chamber test method specified in § 3280.406.
(2) Particleboard materials shall not emit formaldehyde in excess of 0.3 ppm as measured by the air chamber test specified in § 3280.406.
(b) Product certification and continuing qualification. All plywood and particleboard materials to be installed in manufactured homes which are bonded with a resin system or coated with a surface finish containing formaldehyde, other than an exclusively phenol-formaldehyde resin system or finish, shall be certified by a nationally recognized testing laboratory as complying with paragraph (a) of this section.
(1) Separate certification shall be done for each plant where the particleboard is produced or where the plywood or particleboard is surface-finished.
(2) To certify plywood or particleboard, the testing laboratory shall witness or conduct the air chamber test specified in § 3280.406 on randomly selected panels initially and at least quarterly thereafter.
(3) The testing laboratory must approve a written quality control plan for each plant where the particleboard is produced or finished or where the plywood is finished. The quality control plan must be designed to assure that all panels comply with paragraph (a) of this section. The plan must establish ongoing procedures to identify increases in the formaldehyde emission characteristics of the finished product resulting from the following changes in production.
(i) In the case of plywood:
(A) The facility where the unfinished panels are produced is changed;
(B) The thickness of the panels is changed so that the panels are thinner; or
(C) The grooving pattern on the panels is changed so that the grooves are deeper or closer together.
(ii) In the case of particleboard:
(A) The resin formulation is changed so that the formaldehyde-to-urea ratio is increased;
(B) The amount of formaldehyde resin used is increased; or
(C) The press time is decreased.
(iii) In the case of plywood or particleboard:
(A) The finishing or top coat is changed and the new finishing or top coat has a greater formaldehyde content; or
(B) The amount of finishing or top coat used on the panels is increased, provided that such finishing or top coat contains formaldehyde.
(4) The testing laboratory shall periodically visit the plant to monitor quality control procedures to assure that all certified panels meet the standard.
(5) To maintain its certification, plywood or particleboard must be tested by the air chamber test specified in § 3280.406 whenever one of the following events occurs:
(i) In the case of particleboard, the resin formulation is changed so that the formaldehyde-to-urea ratio is increased; or
(ii) In the case of particleboard or plywood, the finishing or top coat is changed and the new finishing or top coat contains formaldehyde; or
(iii) In the case of particleboard or plywood, the testing laboratory determines that an air chamber test is necessary to assure that panels comply with paragraph (a) of this section.
(6) In the event that an air chamber test measures levels of formaldehyde from plywood or particleboard in excess of those permitted under paragraph (a) of this section, then the tested product's certification immediately lapses as of the date of production of the tested panels. No panel produced on the same date as the tested panels or on any day thereafter may be used or certified for use in manufactured homes.
(i) Provided, however, that a new product certification may be obtained by testing randomly selected panels which were produced on any day following the date of production of the tested panels. If such panels pass the air chamber test specified in § 3280.406, then the plywood or particleboard produced on that day and subsequent days may be used and certified for use in manufactured homes.
(ii) Provided further, that plywood or particleboard produced on the same day as the tested panels, and panels produced on subsequent days, if not certified pursuant to paragraph (b)(4)(i) of this section, may be used in manufactured homes only under the following circumstances:
(A) Each panel is treated with a scavenger, sealant, or other means of reducing formaldehyde emissions which does not adversely affect the structural quality of the product; and
(B) Panels randomly selected from the treated panels are tested by and pass the air chamber test specified in § 3280.406.
(c) Panel identification. Each plywood and particleboard panel to be installed in manufactured homes which is bonded or coated with a resin system containing formaldehyde, other than an exclusively phenol-formaldehyde resin system, shall be stamped or labeled so as to identify the product manufacturer, date of production and/or lot number, and the testing laboratory certifying compliance with this section.
(d) Treatment after certification. If certified plywood or particleboard subsequently is treated with paint, varnish, or any other substance containing formaldehyde, then the certification is no longer valid. In such a case, each stamp or label placed on the panels pursuant to paragraph (c) of this section must be obliterated. In addition, the treated panels may be recertified and reidentified in accordance with paragraphs (b) and (c) of this section.
[49 FR 32011, Aug. 9, 1984]
§ 3280.309
Health Notice on formaldehyde emissions.
(a) Each manufactured home shall have a Health Notice on formaldehyde emissions prominently displayed in a temporary manner in the kitchen (i.e., countertop or exposed cabinet face). The Notice shall read as follows:

Important Health Notice
Some of the building materials used in this home emit formaldehyde. Eye, nose, and throat irritation, headache, nausea, and a variety of asthma-like symptoms, including shortness of breath, have been reported as a result of formaldehyde exposure. Elderly persons and young children, as well as anyone with a history of asthma, allergies, or lung problems, may be at greater risk. Research is continuing on the possible long-term effects of exposure to formaldehyde.
Reduced ventilation resulting from energy efficiency standards may allow formaldehyde and other contaminants to accumulate in the indoor air. Additional ventilation to dilute the indoor air may be obtained from a passive or mechanical ventilation system offered by the manufacturer. Consult your dealer for information about the ventilation options offered with this home.
High indoor temperatures and humidity raise formaldehyde levels. When a home is to be located in areas subject to extreme summer temperatures, an air-conditioning system can be used to control indoor temperature levels. Check the comfort cooling certificate to determine if this home has been equipped or designed for the installation of an air-conditioning system.
If you have any questions regarding the health effects of formaldehyde, consult your doctor or local health department.
(b) The Notice shall be legible and typed using letters at least 1/4 inch in size. The title shall be typed using letters at least 3/4 inch in size.
(c) The Notice shall not be removed by any party until the entire sales transaction has been completed (refer to part 3282—Manufactured Home Procedural and Enforcement Regulations for provisions regarding a sales transaction).
(d) A copy of the Notice shall be included in the Consumer Manual (refer to part 3283—Manufactured Home Consumer Manual Requirements).
[49 FR 32012, Aug. 9, 1984, as amended at 54 FR 46049, Nov. 1, 1989; 58 FR 55007, Oct. 25, 1993]

Subpart E—Testing
§ 3280.401
Structural load tests.
Every structural assembly tested shall be capable of meeting the Proof Load Test or the Ultimate Load Test as follows:
(a) Proof load tests. Every structural assembly tested must be capable of sustaining its dead load plus superimposed live loads equal to 1.75 times the required live loads for a period of 12 hours without failure. Tests must be conducted with loads applied and deflections recorded in 1/4 design live load increments at 10-minute intervals until 1.25 times design live load plus dead load has been reached. Additional load shall then be applied continuously until 1.75 times design live load plus dead load has been reached. Assembly failure shall be considered as design live load deflection (or residual deflection measured 12 hours after live load removal) that is greater than the limits set in § 3280.305(d), rupture, fracture, or excessive yielding. Design live load deflection criteria do not apply when the structural assembly being evaluated does not include structural framing members. An assembly to be tested shall be of the minimum quality of materials and workmanship of the production. Each test assembly, component, or subassembly shall be identified as to type and quality or grade of material. All assemblies, components, or subassemblies qualifying under this test shall be subject to a continuing qualification testing program acceptable to HUD.
(b) Ultimate load tests. Ultimate load tests must be performed on a minimum of three assemblies or components to generally evaluate the structural design. Every structural assembly or component tested must be capable of sustaining its total dead load plus the design live load increased by a factor of safety of at least 2.5. A factor of safety greater than 2.5 shall be used when required by an applicable reference standard in § 3280.304(b)(1). Tests shall be conducted with loads applied and deflections recorded in 1/4 design live load increments at 10-minute intervals until 1.25 times design live load plus dead load has been reached. Additional loading shall then be applied continuously until failure occurs, or the total of the factor of safety times the design live load plus the dead load is reached. Assembly failure shall be considered as design live load deflection greater than the limits set in § 3280.305(d), rupture, fracture, or excessive yielding. Design live load deflection criteria do not apply when the structural assembly being evaluated does not include structural framing members. Assemblies to be tested shall be representative of average quality or materials and workmanship of the production. Each test assembly, component, or subassembly shall be identified as to type and quality or grade of material. All assemblies, components, or subassemblies qualifying under this test shall be subject to a periodic qualification testing program acceptable to HUD.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55007, Oct. 25, 1993; 70 FR 72045, Nov. 30, 2005]
§ 3280.402
Test procedures for roof trusses.
(a) Roof load tests. This section provides the roof truss test procedure for vertical loading conditions. Where roof trusses act as support for other members, have eave or cornice projections, or support concentrated loads, roof trusses must also be tested for those conditions. These test procedures are required for new truss designs in all three wind zones and for existing truss designs used in Wind Zones II and III.
(b) General. Trusses must be tested in a truss test fixture that replicates the design loads, and actual support points, and does not restrain horizontal movement. When tested singly or in groups of two or more trusses, trusses shall be mounted on supports and positioned as intended to be installed in the manufactured home in order to give the required clear span distance (L) and eave or cornice distance (Lo), if applicable, as specified in the design.
(l) When trusses are tested singly, trusses shall be positioned in a test fixture, with supports properly located and the roof loads evenly applied. See Figure 3280.402(b)(1).
(2) When tested in groups of two or more, the top chords are permitted to be sheathed with nominal 1/4-inch × 12-inch plywood strips. The plywood strips shall be at least long enough to cover the top chords of the trusses at the designated design truss spacing. Adjacent plywood strips shall be separated by at least 1/8-inch. The plywood strips shall be nailed with 4d nails or equivalent staples no closer than 8 inches on center along the top chord. The bottom chords of the adjacent trusses shall be permitted to be one of the following:
(i) Unbraced; or
(ii) Laterally braced together (not cross-braced) with 1-inch × 2-inch stripping no closer than 24 inches on center, nailed with only one 8d nail at each truss. See Figure 3280.402(b)(2).
(c) Measuring and loading methods. Deflections must be measured at the free end of an eave or cornice projection and at least at the truss mid-span and quarter points. Scissors or other unique truss configurations are to be measured at as many additional bottom chord panel points as necessary to obtain an accurate representation of the deflected shape of the truss so as to be able to locate and record the point(s) of maximum deflection. Deflections must be read and recorded relative to a fixed reference datum. Deflections must be read and recorded to the nearest 1/32-inch. Dead load must be applied to the top and bottom chord, and live load must be applied to the top chord through a suitable hydraulic, pneumatic, or mechanical system or weights to simulate design loads. Load unit weights for uniformly distributed top chord loads must be separated so that arch action does not occur and be spaced not more than 12 inches on center so as to simulate uniform loading. Bottom chord loading must be spaced as uniformly as practical. Truss gravity loads must be calculated based on the overall truss length (horizontal projection), including eave or cornice projections.
(d) Testing procedures. Either the testing method in paragraph (d)(1) or (d)(2) of this section may be used, however, the testing method in paragraph (d)(3) of this section must be used, to test trusses to establish compliance with the provisions of these standards.
(1) Proof load truss test procedure. At least three average quality/consecutively tested trusses must pass all requirements of the test, for initial qualification of the truss design. All tests for initial qualification of the truss designs evaluated by this procedure must be certified by a Registered Engineer or Architect, or by a nationally recognized testing laboratory. An in-house quality control and follow-up testing program (see paragraphs (e) and (f) of this section) must be approved prior to entering production of any truss design evaluated by this procedure.
(i) Dead load. Measure and record initial elevation of the truss or trusses in the test position at no load. Apply to the top and bottom chords of the truss dead loads that are representative of the actual weights of materials to be supported by the truss. However, the dead load may only be applied as indicated in paragraph (e)(4) of this section for ongoing follow-up testing. Dead loads to be applied to the truss test assembly are permitted to include only the weights of materials supported by the truss and not the weight of the truss itself. However, readings from load cells (when used) on which the test truss rests must reflect the sum of the applied load plus the weight of the truss. Apply dead loads and hold for 5 minutes. Measure and record the deflections.
(ii) Live load. Maintaining the dead loads, apply live load to the top chord in approximate 1/4 live load increments until dead load plus the live load is reached. Measure and record the deflections no sooner than one minute after each 1/4 live load increment has been applied and 5 minutes after the full live load has been reached.
(iii) Initial recovery phase. Remove the design live load but not the dead load. Measure and record the deflections 5 minutes after the total live load has been removed.
(iv) Continue to load the truss to:
(A) Dead load plus 2.0 times the design live load. Maintain this loading for 6 hours and inspect the truss for failure. Failure is rupture, fracture, or excessive yielding; or
(B) Dead load plus 1.75 times the design live load. Maintain this loading for 12 hours and inspect the truss for failure. Failure is rupture, fracture, or excessive yielding.
(v) Final recovery phase. Remove 2.0 times the design live load, but not the dead load or 1.75 times the design live load, but not the dead load. Measure and record deflections within 4 hours after removing 2.0 times the design live load or 1.75 times the design live load.
(vi) Acceptance criteria. The truss design is acceptable if all of the following conditions are met:
(A) The maximum deflection between no load and dead load must be L/480 or less for simply supported clear spans and Lo/180 or less for eave and cornice projections; and
(B) The maximum deflection between dead load and design live load must be L/180 or less for simply supported clear spans and Lo/90 or less for eave and cornice projections; and
(C) After the design live load is removed, and with the dead load still applied, the maximum recovery deflection must be L/360 or less for simply supported spans and Lo/180 or less for eave and cornice projections; and
(D) The truss must maintain the overload condition for 6 hours without rupture or fracture, or excessive yielding; and
(E) After 2.0 times the design live load has been removed, and with the dead load still applied, the maximum recovery deflection must be L/180 or less for simply supported clear spans and Lo/90 or less for eave and cornice projections; and
(F) As applicable, each truss design must also meet all requirements for uplift loads required by paragraph (d)(3) of this section. For Wind Zone I uplift load requirements, see paragraph (d)(3)(i) of this section. For Wind Zones II and III uplift load requirements, see paragraph (d)(3)(ii) of this section.
(2) Ultimate load truss test procedure. (i) At least two average quality/consecutively tested trusses must pass all requirements of the test, for initial qualification of the truss design. All tests for initial qualification of the truss designs evaluated by this procedure must be certified by a Registered Engineer or Architect, or by a nationally recognized testing laboratory. An in-house quality control and follow-up testing program (see paragraph (e) and (f) of this section) must be approved prior to entering production of any truss design evaluated by this procedure.
(ii) Dead load. Measure and record initial elevation of the truss or trusses in the test position at no load. Apply to the top and bottom chords of the truss dead loads that are representative of the actual weights of materials to be supported by the truss. However, the dead load may only be applied as indicated in paragraph (e)(4) of this section for ongoing follow-up testing. Dead loads to be applied to the truss test assembly shall be permitted to include only the weights of materials supported by the truss, and not the weight of the truss itself. However, readings from load cells (when used) on which the test truss rests must reflect the sum of the applied load plus the weight of the truss. Apply dead loads and hold for 5 minutes. Measure and record the deflections.
(iii) Live load. Maintaining the dead loads, apply live load at a uniform rate to the top chord in approximate 1/4 live load increments until the dead load plus the live load is reached. Measure and record the deflections no sooner than one minute after each 1/4 live load increment has been applied and 5 minutes after the full live load has been reached.
(iv) Initial recovery phase. Remove the design live load but not the dead load. Measure and record the deflections 5 minutes after the design live load has been removed.
(v) Overload phase. After the recovery phase is completed, reapply the full live load to the truss assembly. Additional loading shall then be applied continuously until the dead load plus 2.5 times the design live load is reached. This overload condition must be maintained for at least 5 minutes.
(vi) Final recovery phase. Remove 2.5 times the design live load but not the dead load. Measure and record deflections within 4 hours after 2.5 times the design live load has been removed.
(vii) Acceptance criteria. The truss design is acceptable if all of the following conditions are met:
(A) The maximum deflection between no load and dead load must be L/480 or less for simply supported clear spans and Lo/180 or less for eave and cornice projections; and
(B) Dead load to design live load deflections shall be L/180 or less for simply supported clear spans and Lo/90 or less for eave and cornice projections; and
(C) After the design live load is removed and with the dead load still applied, the maximum recovery deflection must be L/360 or less for simply supported spans and Lo/180 or less for eave and cornice projections; and
(D) The truss shall maintain the overload condition for 5 minutes without rupture, fracture, or excessive yielding; and
(E) After 2.5 times the design live load is removed, and with the dead load still applied, the truss must recover to at least L/180 for simply supported clear spans and Lo/90 for eave and cornice within 4 hours after the total live load has been removed; and
(F) As applicable, each truss design must also meet all requirements for uplift loads in Wind Zone I or Wind Zone II and III, as required by paragraph (d)(3) of this section. For Wind Zone I uplift load requirements, see paragraph (d)(3)(i) of this section. For Wind Zones II and III uplift load requirements, see paragraph (d)(3)(ii) of this section.
(3) Uplift load tests. Each truss design must also pass all requirements of the uplift load test, as applicable, in paragraph (d)(3)(i) or (d)(3)(ii) and paragraphs (d)(3)(iii) and (d)(3)(iv) of this section.
(i) Wind Zone I uplift load test. Where there are engineered connectors between the top chord and web members of the truss, such as metal connector plates or wood gussets or their equivalents, uplift testing in Wind Zone I is at the discretion of the Registered Engineer or Architect or nationally recognized testing laboratory certifying the truss design. When testing is deemed necessary by the Registered Engineer or Architect or nationally recognized testing laboratory certifying the truss design, a minimum of one average quality uplift load test is to be conducted for each such truss design and must pass all requirements of the test for initial qualification of the truss design. The net uplift load for trusses designed for use in Wind Zone I is 9 psf for the clear span of the truss and 22.5 psf for eave or cornice projections.
(ii) Wind Zones II and III uplift loads test. This test is required for all trusses designed for use in Wind Zones II and III. A minimum of three average quality/consecutive uplift load tests are to be conducted for each truss design when tested in the inverted position and a minimum of two average quality/consecutive uplift load tests are to be conducted for trusses in the upright position. The trusses must pass all requirements of the test for initial qualification of the truss design. The uplift load for trusses designed to be used in Wind Zones II and III for the clear span or eave cornice projections is to be determined by subtracting the dead load applied to the truss from the uplift load provided in the Table of Design Wind Pressures in § 3280.305(c)(1)(ii)(B).
(iii) Trusses designed for use in Wind Zone I, when tested (see paragraph (d)(3)(i) of this section), must be tested in either the inverted position to 2.5 times the net wind uplift load or in the upright position to 1.75 times the net wind uplift load. Trusses designed for use in Wind Zones II and III (see paragraph (d)(3)(ii) of this section) must be tested to 2.0 times the uplift load minus the dead load in the inverted position and to 1.75 times the uplift load minus the dead load in the upright position. See Figure 3280.402(b)(3).
(iv) The following describes how to conduct the uplift test with the truss in the upright position. Similar procedures must be used if conducting the test in the inverted position.
(A) Place the truss in the test fixture and position as it is intended to be installed in the manufactured home. See Figure 3280.402(b)(3).
(B) Position the load measurement devices to register the wind uplift loads that will be applied to the top chord of the truss. The uplift loads shall be applied through tension devices not wider than one inch and spaced not greater than approximately 12 inches on center and shall be applied as uniform as possible, so as to simulate uniform loading. Gravity and wind uplift load tests may be performed on the same truss in this single setup mode. For the wind uplift test, it is permissible to stabilize the bottom chord of the truss in the test fixture to simulate ceiling materials or purlin supports. Measure and record the initial elevation of the bottom chord of the truss in the test position at the mid-span and quarter points of the truss, and at the free end of an eave or cornice projection greater than 12 inches. Scissors or other unique truss configurations are to be measured at as many additional bottom chord panel points as necessary to obtain an accurate representation of the deflected shape of the truss, so as to be able to locate and record the point(s) of maximum deflection. Eave or cornice projection loads are applied separately for eaves or cornice projections greater than 12 inches. For eave or cornice projections greater than 12 inches, the additional required load must be applied to the eave simultaneously with the main body load. For eave or cornice projections of 12 inches or less, add the additional required load to the main body load and apply it to the entire top chord.
(C) Measure and record the deflection 5 minutes after the net uplift load has been applied. Design load deflection shall be L/180 or less for a simply supported clear span and Lo/90 or less for eave or cornice projections.
(D) For trusses tested in the upright position, continue to load the truss to 1.75 times the net uplift load in paragraph (d)(3)(i) of this section for Wind Zone I and 1.75 times the uplift load in paragraph (d)(3)(ii) for Wind Zones II and III, and maintain the load for one minute. For trusses tested in the inverted position, continue to load the truss to 2.50 times the net uplift load in paragraph (d)(3)(i) for Wind Zone I and to 2.0 times the uplift load minus the dead load in paragraph (d)(3)(ii) for Wind Zones II and III, and maintain the full load for one minute. Regardless of the test position of the truss, upright or inverted, trusses must maintain the overload for the specified time period without rupture, fracture, or excessive yielding.
(e) Follow-up testing. Follow-up testing procedures must include the following:
(1) All trusses qualifying under these test procedures must be subject to a quality control and follow-up testing program.
(i) Manufacturers of listed or labeled trusses must follow an in-house quality control program with follow-up testing approved by a nationally recognized testing program as specified in paragraph (e)(3) of this section. The in-house quality control program must include, at a minimum, procedures for quality of materials including, but not limited to, grade(s) of materials, allowable splits, knots, and other applicable lumber qualities; workmanship including, but not limited to, plate placement and embedment tolerances; other manufacturing tolerances; description and calibration of test equipment; truss retesting criteria; and procedures in the event of noncomplying results.
(ii) Those home manufacturers producing trusses for their own use, and which are not listed or labeled, must have an in-house quality control program (see paragraph (i) of this section) that includes follow-up testing, as specified in this section, and is approved by their Design Approval Primary Inspection Agency (DAPIA).
(2) Truss designs that are qualified but not in production are not subject to follow-up testing until produced. When the truss design is brought into production, a follow-up test is to be performed if the truss design has been out of production for more than 6 months.
(3) The frequency of truss manufacturer's quality control follow-up testing for trusses must be at least:
(i) One test for the first 100 trusses produced, with a subsequent test for every 2,500 trusses for trusses qualified under the proof load truss test procedure or inverted uplift test procedure for trusses used in Wind Zones II and III or once every 6 months, whichever is more frequent, for every truss design produced; or
(ii) One test for every 4,000 trusses produced for trusses qualified under the ultimate load truss test procedure or upright uplift test procedure for trusses used in Wind Zones II and III or once every 6 months, whichever is more frequent, for every truss design produced.
(4) For follow-up testing only, the full dead load may be applied to the top chord of the truss, when the bottom chord dead load is 5 psf or less.
[78 FR 4065, Jan. 18, 2013]
§ 3280.403
Requirements for windows, sliding glass doors, and skylights.
(a) Scope. This section establishes the requirements for prime windows and sliding glass doors, except that windows used in an entry door are components of the door and are excluded from these requirements.
(b)(1) Standard. All primary windows and sliding glass doors shall comply with AAMA 1701.2-95, Voluntary Standard Primary Window and Sliding Glass Door for Utilization in Manufactured Housing, except the exterior and interior pressure tests must be conducted at the design wind loads required for components and cladding specified in § 3280.305(c)(1).
(2) All skylights must comply with AAMA/WDMA/CSA/101/I.S.2/A440-08: North American Fenestration Standard/Specifications for Windows, Doors and Skylights (incorporated by reference, see § 3280.4). Skylights must withstand the roof loads for the applicable Roof Load Zone specified in § 3280.305(c)(3), and the following wind loads:
(i) For Wind Zone I, the wind loads specified in § 3280.305(c)(1)(i); and
(ii) For Wind Zones II and III, the wind loads specified for exterior roof coverings, sheathing, and fastenings in § 3280.305(c)(1)(ii).
(c) Installation. All primary windows, sliding glass doors, and skylights must be installed in a manner that allows proper operation and provides protection against the elements, as required by § 3280.307.
(d) Glass. (1) Safety glazing materials, where used shall meet Standard for Safety Glazing Materials used in Buildings—Safety Performance Specifications and Methods of Test, ANSI Z97.1-2004 (incorporated by reference, see § 3280.4).
(2) Sealed insulating glass, where used, must meet all performance requirements for Class C in accordance with ASTM E 774-97, Standard Specification for the Classification of the Durability of Sealed Insulating Glass Units. The sealing system must be qualified in accordance with ASTM E 773-97, Standard Test Methods for Accelerated Weathering of Sealed Insulating Glass Units. Each glass unit must be permanently identified with the name of the insulating glass manufacturer.
(e) Certification. All primary windows and sliding glass doors to be installed in manufactured homes must be certified as complying with AAMA 1701.2-95. This certification must be based on tests conducted at the design wind loads specified in § 3280.305(c)(1).
(1) All such windows and doors must show evidence of certification by affixing a quality certification label to the product in accordance with ANSI Z34.1-1993, Third-Party Certification Programs for Products, Processes, and Services.
(2) In determining certifiability of the products, an independent quality assurance agency shall conduct pre-production specimen tests in accordance with AAMA 1701.2-95. Further, such agency must inspect the product manufacturer's facility at least twice per year.
(3) All skylights installed in manufactured homes must be certified as complying with AAMA/WDMA/CSA 101/I.S.2/A440-08: North American Fenestration Standard/Specifications for Windows, Doors, and Skylights (incorporated by reference, see § 3280.4). This certification must be based on applicable loads specified in paragraph (b) of this section.
(f) Protection of primary window and sliding glass door openings in high wind areas. For homes designed to be located in Wind Zones II and III, manufacturers shall design exterior walls surrounding the primary window and sliding glass door openings to allow for the installation of shutters or other protective covers, such as plywood, to cover these openings. Although not required, the Department encourages manufacturers to provide the shutters or protective covers and to install receiving devices, sleeves, or anchors for fasteners to be used to secure the shutters or protective covers to the exterior walls. If the manufacturer does not provide shutters or other protective covers to cover these openings, the manufacturer must provide to the homeowner instructions for at least one method of protecting primary window and sliding glass door openings. This method must be capable of resisting the design wind pressures specified in § 3280.305 without taking the home out of conformance with the standards in this part. These instructions must be included in the printed instructions that accompany each manufactured home. The instructions shall also indicate whether receiving devices, sleeves, or anchors, for fasteners to be used to secure the shutters or protective covers to the exterior walls, have been installed or provided by the manufacturer.
[52 FR 4583, Feb. 12, 1987, as amended at 52 FR 35543, Sept. 22, 1987; 58 FR 55009, Oct. 25, 1993; 59 FR 2474, Jan. 14, 1994; 70 FR 72046, Nov. 30, 2005; 78 FR 73983, Dec. 9, 2013]
§ 3280.404
Standard for egress windows and devices for use in manufactured homes.
(a) Scope and purpose. The purpose of this section is to establish the requirements for the design, construction, and installation of windows and approved devices intended to be used as an emergency exit during conditions encountered in a fire or similar disaster.
(b) Performance. Egress windows including auxiliary frame and seals, if any, shall meet all requirements of AAMA 1701.2-95, Voluntary Standard Primary Window and Sliding Glass Door for Utilization in Manufactured Housing and AAMA Standard 1704-1985, Voluntary Standard Egress Window Systems for Utilization in Manufactured Housing, except the exterior and interior pressure tests for components and cladding must be conducted at the design wind loads required by § 3280.305(c)(1).
(c) Installation. (1) The installation of egress windows or devices shall be installed in a manner which allows for proper operation and provides protection against the elements. (See § 3280.307.)
(2) An operational check of each installed egress window or device must be made at the manufactured home factory. All egress windows and devices must be capable of being opened to the minimum required dimensions by normal operation of the window without binding or requiring the use of tools. Any window or device failing this check must be repaired or replaced. A repaired window must conform to its certification. Any repaired or replaced window or device must pass the operational check.
(3) Windows that require the removal of the sash to meet egress size requirements are prohibited.
(d) Operating instructions. Operating instructions shall be affixed to each egress window and device and carry the legend “Do Not Remove.”
(e) Certification of egress windows and devices. Egress windows and devices shall be listed in accordance with the procedures and requirements of AAMA Standard 1704-1985. As of January 17, 1995, this certification must be based on tests conducted at the design wind loads specified in § 3280.305(c)(1).
(f) Protection of egress window openings in high wind areas. For homes designed to be located in Wind Zones II and III, manufacturers shall design exterior walls surrounding the egress window openings to allow for the installation of shutters or other protective covers, such as plywood, to cover these openings. Although not required, the Department encourages manufacturers to provide the shutters or protective covers and to install receiving devices, sleeves, or anchors for fasteners to be used to secure the shutters or protective covers to the exterior walls. If the manufacturer does not provide shutters or other protective covers to cover these openings, the manufacturer must provide to the homeowner instructions for at least one method of protecting egress window openings. This method must be capable of resisting the design wind pressures specified in § 3280.305 without taking the home out of conformance with the standards in this part. These instructions must be included in the printed instructions that accompany each manufactured home. The instructions shall also indicate whether receiving devices, sleeves, or anchors, for fasteners to be used to secure the shutters or protective covers to the exterior walls, have been installed or provided by the manufacturer.
[52 FR 4583, Feb. 12, 1987, as amended at 59 FR 2474, Jan. 14, 1994; 70 FR 72046, Nov. 30, 2005; 78 FR 73983, Dec. 9, 2013]
§ 3280.405
Standard for swinging exterior passage doors for use in manufactured homes.
(a) Introduction. This standard applies to all exterior passage door units, excluding sliding doors and doors used for access to utilities and compartments. This standard applies only to the door frame consisting of jambs, head and sill and the attached door or doors.
(b) Performance requirements. The design and construction of exterior door units must meet all requirements of AAMA 1702.2-95, Voluntary Standard Swinging Exterior Passage Door for Utilization in Manufactured Housing.
(c) Materials and methods. Any material or method of construction shall conform to the performance requirements as outlined in paragraph (b) of this section. Plywood shall be exterior type and preservative treated in accordance with NWWDA I.S.4-81, Water Repellent Preservative Non-Pressure Treatment for Millwork.
(d) Exterior doors. All swinging exterior doors shall be installed in a manner which allows proper operation and provides protection against the elements (see § 3280.307).
(e) Certification. All swinging exterior doors to be installed in manufactured homes must be certified as complying with AAMA 1702.2-95, Voluntary Standard Swinging Exterior Passage Door for Utilization in Manufactured Housing.
(1) All such doors must show evidence of certification by affixing a quality certification label to the product in accordance with ANSI Z34.1-1993, Third Party Certification Programs for Products, Processes, and Services.
(2) In determining certifiability of the products, an independent quality assurance agency must conduct a pre-production specimen test in accordance with AAMA 1702.2-95, Voluntary Standard Swinging Exterior Passage Door for Utilization in Manufactured Housing.
(f) Protection of exterior doors in high wind areas. For homes designed to be located in Wind Zones II and III, manufacturers shall design exterior walls surrounding the exterior door openings to allow for the installation of shutters or other protective covers, such as plywood, to cover these openings. Although not required, the Department encourages manufacturers to provide the shutters or protective covers and to install receiving devices, sleeves, or anchors for fasteners to be used to secure the shutters or protective covers to the exterior walls. If the manufacturer does not provide shutters or other protective covers to cover these openings, the manufacturer must provide to the homeowner instructions for at least one method of protecting exterior door openings. This method must be capable of resisting the design wind pressures specified in § 3280.305 without taking the home out of conformance with the standards in this part. These instructions must be included in the printed instructions that accompany each manufactured home. The instructions shall also indicate whether receiving devices, sleeves, or anchors, for fasteners to be used to secure the shutters or protective covers to the exterior walls, have been installed or provided by the manufacturer.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4583, Feb. 12, 1987; 52 FR 35543, Sept. 22, 1987; 58 FR 55009, Oct. 25, 1993; 59 FR 2474, Jan. 14, 1994; 70 FR 72046, Nov. 30, 2005]
§ 3280.406
Air chamber test method for certification and qualification of formaldehyde emission levels.
(a) Preconditioning. Preconditioning of plywood or particleboard panels for air chamber tests shall be initiated as soon as practicable but not in excess of 30 days after the plywood or particleboard is produced or surface-finished, whichever is later, using randomly selected panels.
(1) If preconditioning is to be initiated more than two days after the plywood or particleboard is produced or surface-finished, whichever is later, the panels must be dead-stacked or air-tight wrapped until preconditioning is initiated.
(2) Panels selected for testing in the air chamber shall not be taken from the top or bottom of the stack.
(b) Testing. Testing must be conducted in accordance with the Standard Test Method for Determining Formaldehyde Levels from Wood Products Under Defined Test Conditions Using a Large Chamber, ASTM E 1333-96, with the following exceptions:
(1) The chamber shall be operated indoors.
(2) Plywood and particleboard panels shall be individually tested in accordance with the following loading ratios:
(i) Plywood—0.29 Ft2/Ft3, and
(ii) Particleboard—0.13 Ft2/Ft3.
(3) Temperature to be maintained inside the chamber shall be 77° plus or minus 2 °F.
(4) The test concentration (C) shall be standardized to a level (CO) at a temperature (t O) of 77 °F and 50% relative humidity (HO) by the following formula:
C = CO × [1 + Ax (H − HO)] × e−R(1 / t − 1 / t O)
where:
C = Test formaldehyde concentration
CO = Standardized formaldehyde concentration
e = Natural log base
R = Coefficient of temperature (9799)
t = Actual test condition temperature (^O K)
t O = Standardized temperature (^O K)
A = Coefficient of humidity (0.0175)
H = Actual relative humidity (%)
HO = Standardized relative humidity (%)
The standardized level (CO) is the concentration used to determine compliance with § 3280.308(a).
(5) The air chamber shall be inspected and recalibrated at least annually to insure its proper operation under test conditions.
[49 FR 32012, Aug. 9, 1984, as amended at 58 FR 55009, Oct. 25, 1993; 70 FR 72046, Nov. 30, 2005]

Subpart F—Thermal Protection
§ 3280.501
Scope.
This subpart sets forth the requirements for condensation control, air infiltration, thermal insulation and certification for heating and comfort cooling.
§ 3280.502
Definitions.
(a) The following definitions are applicable to subpart F only:
(1) Pressure envelope means that primary air barrier surrounding the living space which serves to limit air leakage. In construction using ventilated cavities, the pressure envelope is the interior skin.
(2) Thermal envelope area means the sum of the surface areas of outside walls, ceiling and floor, including all openings. The wall area is measured by multiplying outside wall lengths by the inside wall height from floor to ceiling. The floor and ceiling areas are considered as horizontal surfaces using exterior width and length.
§ 3280.503
Materials.
Materials used for insulation shall be of proven effectiveness and adequate durability to assure that required design conditions concerning thermal transmission are attained.
§ 3280.504
Condensation control and installation of vapor retarders.
(a) Ceiling vapor retarders. (1) In Uo Value Zones 2 and 3, ceilings must have a vapor retarder with a permeance of not greater than 1 perm (as measured by ASTM E 96-95 Standard Test Methods for Water Vapor Transmission of Materials) (incorporated by reference, see § 3280.4) installed on the living space side of the roof cavity.
(2) For manufactured homes designed for Uo Value Zone 1, the vapor retarder may be omitted.
(b) Exterior walls. (1) Exterior walls must have a vapor retarder with a permeance no greater than 1 perm (dry cup method) installed on the living space side of the wall; or
(2) Unventilated wall cavities must have an external covering and/or sheathing that forms the pressure envelope. The covering and/or sheathing must have a combined permeance of not less than 5.0 perms. In the absence of test data, combined permeance is permitted to be computed using the following formula: P total = (1/[(1/P1) + (1/P2)]), where P1 and P2 are the permeance values of the exterior covering and sheathing in perms. Formed exterior siding applied in sections with joints not caulked or sealed, are not considered to restrict water vapor transmission; or
(3) Wall cavities must be constructed so that ventilation is provided to dissipate any condensation occurring in these cavities; or
(4) Homes manufactured to be sited in “humid climates” or “fringe climates” as shown on the Humid and Fringe Climate Map in this paragraph are permitted to have a vapor retarder specified in paragraph (b)(1) of this section installed on the exterior side of the wall insulation or be constructed with an external covering and sheathing with a combined permeance of not greater than 1.0 perms, provided the interior finish and interior wall panel materials have a combined permeance of not less than 5.0 perms. The following need not meet the minimum combined permeance rating of not less than 5.0 perms for interior finish or wall panel materials:
(i) Kitchen back splash materials, less than 50 square feet in area installed around countertops, sinks, and ranges;
(ii) Bathroom tub areas, shower compartments;
(iii) Cabinetry and built-in furniture;
(iv) Trim materials;
(v) Hardboard wall paneling of less than 50 square feet in area under chair rails.
(5) The following areas of local governments (counties or similar areas, unless otherwise specified), listed by state are deemed to be within the humid and fringe climate areas shown on the Humid and Fringe Climate Map in paragraph (b)(4) of this section, and the vapor retarder or construction methods specified in paragraph (b)(4) of this section may be applied to homes built to be sited within these jurisdictions:

Alabama
Baldwin, Barbour, Bullock, Butler, Choctaw, Clarke, Coffee, Conecuh, Covington, Crenshaw, Dale, Escambia, Geneva, Henry, Houston, Lowndes, Marengo, Mobile, Monroe, Montgomery, Pike, Washington, Wilcox.

Florida
All counties and locations within the State of Florida.

Georgia
Appling, Atkinson, Bacon, Baker, Ben Hill, Berrien, Brantley, Brooks, Bryan, Calhoun, Camden, Charlton, Chatham, Clay, Clinch, Coffee, Colquitt, Cook, Crisp, Decatur, Dougherty, Early, Echols, Effingham, Evans, Glynn, Wayne, Grady, Irwin, Jeff Davis, Lanier, Lee, Liberty, Long, Lowndes, McIntosh, Miller, Mitchell, Pierce, Quitman, Randolph, Seminole, Tattnall, Terrell, Thomas, Tift, Turner, Ware, Worth.

Hawaii
All counties and locations within the State of Hawaii.

Louisiana
All counties and locations within the State of Louisiana.

Mississippi
Adams, Amite, Claiborne, Clarke, Copiah, Covington, Forrest, Franklin, George, Greene, Hancock, Harrison, Hinds, Issaquena, Jackson, Jasper, Jefferson, Jefferson Davis, Jones, Lamar, Lawrence, Lincoln, Marion, Pearl River, Perry, Pike, Rankin, Simpson, Smith, Stone, Walthall, Warren, Wayne, Wilkinson.

North Carolina
Brunswick, Carteret, Columbus, New Hanover, Onslow, Pender.

South Carolina
Jasper, Beaufort, Colleton, Dorchester, Charleston, Berkeley, Georgetown, Horry.

Texas
Anderson, Angelina, Aransas, Atascosa, Austin, Bastrop, Bee, Bexar, Brazoria, Brazos, Brooks, Burleson, Caldwell, Calhoun, Cameron, Camp, Cass, Chambers, Cherokee, Colorado, Comal, De Witt, Dimmit, Duval, Falls, Fayette, Fort Bend, Franklin, Freestone, Frio, Galveston, Goliad, Gonzales, Gregg, Grimes, Guadalupe, Hardin, Harris, Harrison, Hays, Henderson, Hidalgo, Hopkins, Houston, Jackson, Jasper, Jefferson, Jim Hogg, Jim Wells, Karnes, Kaufman, Kennedy, Kinney, Kleberg, La Salle, Lavaca, Lee, Leon, Liberty, Limestone, Live Oak, Madison, Marion, Matagorda, Maverick, McMullen, Medina, Milam, Montgomery, Morris, Nacogdoches, Navarro, Newton, Nueces, Orange, Panola, Polk, Rains, Refugio, Robertson, Rusk, Sabine, San Augustine, San Jacinto, San Patricio, Shelby, Smith, Starr, Titus, Travis, Trinity, Tyler, Upshur, Uvalde, Val Verde, Van Zandt, Victoria, Walker, Waller, Washington, Webb, Wharton, Willacy, Williamson, Wilson, Wood, Zapata, Zavala.
(c) Liquid applied vapor retarders. Each liquid applied vapor retarder must be tested by a nationally recognized testing agency for use on the specific substrate to which it is applied. The test report must include the perm rating, as measured by ASTM E 96-95, Standard Test Methods for Water Vapor Transmission of Materials, and associated application rate for each specific substrate.
(d) Attic or roof ventilation. (1) Attic and roof cavities shall be vented in accordance with one of the following:
(i) A minimum free ventilation area of not less than 1/300 of the attic or roof cavity floor area. At least 50 percent of the required free ventilation area shall be provided by ventilators located in the upper portion of the space to be ventilated. At least 40 percent shall be provided by eave, soffit or low gable vents. The location and spacing of the vent openings and ventilators shall provide cross-ventilation to the entire attic or roof cavity space. A clear air passage space having a minimum height of 1 inch shall be provided between the top of the insulation and the roof sheathing or roof covering. Baffles or other means shall be provided where needed to insure the 1 inch height of the clear air passage space is maintained.
(ii) A mechanical attic or roof ventilation system may be installed instead of providing the free ventilation area when the mechanical system provides a minimum air change rate of 0.02 cubic feet per minute (cfm) per sq. ft. of attic floor area. Intake and exhaust vents shall be located so as to provide air movement throughout space.
(2) Single section manufactured homes constructed with metal roofs and having no sheathing or underlayment installed, are not required to be provided with attic or roof cavity ventilation provided that the air leakage paths from the living space to the roof cavity created by electrical outlets, electrical junctions, electrical cable penetrations, plumbing penetrations, flue pipe penetrations and exhaust vent penetrations are sealed.
(3) Parallel membrane roof section of a closed cell type construction are not required to be ventilated.
(4) The vents provided for ventilating attics and roof cavities shall be designed to resist entry of rain and insects.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55009, Oct. 25, 1993; 70 FR 72046, Nov. 30, 2005; 71 FR 19639, Apr. 17, 2006; 78 FR 73984, Dec. 9, 2013]
§ 3280.505
Air infiltration.
(a) Envelope air infiltration. The opaque envelope shall be designed and constructed to limit air infiltration to the living area of the home. Any design, material, method or combination thereof which accomplishes this goal may be used. The goal of the infiltration control criteria is to reduce heat loss/heat gain due to infiltration as much as possible without impinging on health and comfort and within the limits of reasonable economics.
(1) Envelope penetrations. Plumbing, mechanical and electrical penetrations of the pressure envelope not exempted by this part, and installations of window and door frames shall be constructed or treated to limit air infiltration. Penetrations of the pressure envelope made by electrical equipment, other than distribution panel boards and cable and conduit penetrations, are exempt from this requirement. Cable penetrations through outlet boxes are considered exempt.
(2) Joints between major envelope elements. Joints not designed to limit air infiltration between wall-to-wall, wall-to-ceiling and wall-to-floor connections shall be caulked or otherwise sealed. When walls are constructed to form a pressure envelope on the outside of the wall cavity, they are deemed to meet this requirement.
§ 3280.506
Heat loss/heat gain.
The manufactured home heat loss/heat gain shall be determined by methods outlined in §§ 3280.508 and 3280.509. The Uo (Coefficient of heat transmission) value zone for which the manufactured home is acceptable and the lowest outdoor temperature to which the installed heating equipment will maintain a temperature of 70 F shall be certified as specified in § 3280.510 of this subpart. The Uo value zone shall be determined from the map in figure 506.
(a) Coefficient of heat transmission. The overall coefficient of heat transmission (Uo) of the manufactured home for the respective zones and an indoor design temperature of 70 F, including internal and external ducts, and excluding infiltration, ventilation and condensation control, shall not exceed the Btu/(hr.) (sq. ft.) (F) of the manufactured home envelope are as tabulated below:
Uo value zone | Maximum coefficient of heat transmission
1 | 0.116 Btu/(hr.) (sq. ft.) (F).
2 | 0.096 Btu/(hr.) (sq. ft.) (F).
3 | 0.079 Btu/(hr.) (sq. ft.) (F).
(b) To assure uniform heat transmission in manufactured homes, cavities in exterior walls, floors, and ceilings shall be provided with thermal insulation.
(c) Manufactured homes designed for Uo Value Zone 3 shall be factory equipped with storm windows or insulating glass.
[58 FR 55009, Oct. 25, 1993; 59 FR 15113, Mar. 31, 1994]
§ 3280.507
Comfort heat gain.
Information necessary to calculate the home cooling load shall be provided as specified in this part.
(a) Transmission heat gains. Homes complying with this section shall meet the minimum heat loss transmission coefficients specified in § 3280.506(a).
§ 3280.508
Heat loss, heat gain and cooling load calculations.
(a) Information, values and data necessary for heat loss and heat gain determinations must be taken from the 1997 ASHRAE Handbook of Fundamentals, Inch-Pound Edition, chapters 22 through 27. The following portions of those chapters are not applicable:
23.1 Steel Frame Construction
23.2 Masonry Construction
23.3 Foundations and Floor Systems
23.15 Pipes
23.17 Tanks, Vessels, and Equipment
23.18 Refrigerated Rooms and Buildings
24.18 Mechanical and Industrial Systems
25.19 Commercial Building Envelope Leakage
27.9 Calculation of Heat Loss from Crawl Spaces
(b) The calculation of the manufactured home's transmission heat loss coefficient (Uo) must be in accordance with the fundamental principles of the 1997 ASHRAE Handbook of Fundamentals, Inch-Pound Edition, and, at a minimum, must address all the heat loss or heat gain considerations in a manner consistent with the calculation procedures provided in the document, Overall U-values and Heating/Cooling Loads—Manufactured Homes—February 1992-PNL 8006, HUD User No. 0005945.
(c) Areas where the insulation does not fully cover a surface or is compressed shall be accounted for in the U-calculation (see § 3280.506). The effect of framing on the U-value must be included in the Uo calculation. Other low-R-value heat-flow paths (“thermal shorts”) shall be explicitly accounted for in the calculation of the transmission heat loss coefficient if in the aggregate all types of low-R-value paths amount to more than 1% of the total exterior surface area. Areas are considered low-R-value heat-flow paths if:
(1) They separate conditioned and unconditioned space; and
(2) They are not insulated to a level that is at least one-half the nominal insulation level of the surrounding building component.
(d) High efficiency heating and cooling equipment credit. The calculated transmission heat loss coefficient (Uo) used for meeting the requirement in § 3280.506(a) may be adjusted for heating and cooling equipment above that required by the National Appliance Energy Conservation Act of 1987 (NAECA) by applying the following formula:
Uo adjusted = Uo standard × [1 + (0.6) (heating efficiency increase factor) + (cooling multiplier) (cooling efficiency increase factor)]
where:
Uo standard = Maximum Uo for Uo Zone required by § 3280.506(a)
Uo adjusted = Maximum Uo standard adjusted for high efficiency HVAC equipment
Heating efficiency increase factor = The increase factor in heating equipment efficiency measured by the Annual Fuel Utilization Efficiency (AFUE), or the Heating Seasonal Performance Factor (HSPF) for heat pumps, above that required by NAECA (indicated as “NAECA” in formula). The formula is heating efficiency increase factor = AFUE (HSPF) home − AFUE (or HSPF) NAECA divided by AFUE (HSPF) NAECA.
Cooling efficiency increase factor = the increase factor in the cooling equipment efficiency measured by the Seasonal Energy Efficiency Ratio (SEER) above that required by NAECA.
The formula being cooling equipment = SEER home—SEER NAECA divided by SEER NAECA.
The cooling multiplier for the Uo Zone is from the following table:
Uo zone | Cooling multiplier (Cm)
1 | 0.60 (Florida only).
1 | 0.20 (All other locations).
2 | 0.07.
3 | 0.03.
(e) U values for any glazing (e.g., windows, skylights, and the glazed portions of any door) must be based on tests using AAMA 1503.1-1988, Voluntary Test Method for Thermal Transmittance and Condensation Resistance of Windows, Doors, and Glazed Wall Sections, or the National Fenestration Rating Council 100, 1997 Edition, Procedure for Determining Fenestration Product U-factors. In the absence of tests, manufacturers are to use the residential window U values contained in Chapter 29, Table 5 of the 1997 ASHRAE Handbook of Fundamentals, Inch-Pound Edition. In the event that the classification of the window type is indeterminate, the manufacturer must use the classification that gives the higher U value. Where a composite of materials from two different product types is used, the product is to be assigned the higher U value. For the purpose of calculating Uo values, storm windows are treated as an additional pane.
(f) Annual energy used based compliance. As an alternative, homes may demonstrate compliance with the annual energy used implicit in the coefficient of heat transmission (Uo) requirement. The annual energy use determination must be based on generally accepted engineering practices. The general requirement is to demonstrate that the home seeking compliance approval has a projected annual energy use, including both heating and cooling, less than or equal to a similar “base case” home that meets the standard. The energy use for both homes must be calculated based on the same assumptions; including assuming the same dimensions for all boundaries between conditioned and unconditioned spaces, site characteristics, usage patterns and climate.
[58 FR 55011, Oct. 25, 1993, as amended at 70 FR 72047, Nov. 30, 2005]
§ 3280.509
Criteria in absence of specific data.
In the absence of specific data, for purposes of heat-loss/gain calculation, the following criteria shall be used:
(a) Infiltration heat loss. In the absence of measured infiltration heat loss data, the following formula shall be used to calculate heat loss due to infiltration and intermittently operated fans exhausting to the outdoors. The perimeter calculation shall be based on the dimensions of the pressure envelope.
Infiltration Heat-Loss = 0.7 (T) (ft. of perimeter), BTU/hr.
where: T = 70 minus the heating system capacity certification temperature stipulated in the Heating Certificate, in F.
(b) Framing areas.
Wall | 15 percent of wall area less windows and doors.
Floor and Ceiling | 10 percent of the area.
(c) Insulation compression. Insulation compressed to less than nominal thickness and loose-fill insulation in sloping cavities must have its nominal R-values reduced in compressed areas in accordance with the following table:
Table to Paragraph (c)—Effect of Insulation Compression and Restriction on R-Values
Original thickness (%) | Non-uniform (a) restriction | Batt (%) | Blown (%) | Uniform (b) compression batt (%)
0 | 20 | 15 | 0
1 | 26 | 21 | 1
2 | 32 | 25 | 2
3 | 36 | 28 | 4
4 | 38 | 30 | 5
5 | 41 | 32 | 7
6 | 43 | 33 | 8
7 | 45 | 35 | 10
8 | 46 | 36 | 11
9 | 48 | 38 | 13
10 | 49 | 39 | 14
11 | 51 | 40 | 15
12 | 52 | 42 | 17
13 | 53 | 43 | 18
14 | 54 | 44 | 20
15 | 55 | 45 | 21
16 | 57 | 46 | 22
17 | 58 | 47 | 24
18 | 59 | 48 | 25
19 | 59 | 49 | 26
| 20 | 60 | 50 | 28
21 | 61 | 51 | 29
22 | 62 | 52 | 30
23 | 63 | 52 | 31
24 | 64 | 53 | 33
25 | 65 | 54 | 34
26 | 65 | 55 | 35
27 | 66 | 56 | 36
28 | 67 | 57 | 37
29 | 68 | 57 | 39
30 | 68 | 58 | 40
31 | 69 | 59 | 41
32 | 70 | 60 | 42
33 | 70 | 60 | 43
34 | 71 | 61 | 44
35 | 72 | 62 | 45
36 | 72 | 63 | 47
37 | 73 | 63 | 48
38 | 74 | 64 | 49
39 | 74 | 65 | 50
40 | 75 | 65 | 51
41 | 75 | 66 | 52
42 | 76 | 67 | 53
43 | 76 | 68 | 54
44 | 77 | 68 | 55
45 | 78 | 69 | 56
46 | 78 | 70 | 57
47 | 79 | 70 | 58
48 | 79 | 71 | 59
49 | 80 | 71 | 60
50 | 80 | 72 | 61
51 | 81 | 73 | 62
52 | 81 | 73 | 63
53 | 82 | 74 | 64
54 | 82 | 75 | 65
55 | 83 | 75 | 65
56 | 83 | 76 | 66
57 | 84 | 76 | 67
58 | 84 | 77 | 68
59 | 84 | 78 | 69
60 | 85 | 78 | 70
61 | 85 | 79 | 71
62 | 86 | 79 | 72
63 | 86 | 80 | 73
64 | 87 | 81 | 74
65 | 87 | 81 | 74
66 | 88 | 82 | 75
67 | 88 | 82 | 76
68 | 88 | 83 | 77
69 | 89 | 84 | 78
70 | 89 | 84 | 78
71 | 90 | 85 | 79
72 | 90 | 85 | 80
73 | 90 | 86 | 81
74 | 91 | 86 | 82
75 | 91 | 87 | 82
76 | 92 | 87 | 83
77 | 92 | 88 | 84
78 | 92 | 89 | 85
79 | 93 | 89 | 85
80 | 93 | 90 | 86
81 | 93 | 90 | 87
82 | 94 | 91 | 88
83 | 94 | 91 | 88
84 | 95 | 92 | 89
85 | 95 | 92 | 90
86 | 95 | 93 | 91
87 | 96 | 93 | 91
88 | 96 | 94 | 92
89 | 96 | 94 | 93
90 | 97 | 95 | 93
91 | 97 | 95 | 94
92 | 97 | 96 | 95
93 | 98 | 96 | 95
94 | 98 | 97 | 96
95 | 98 | 97 | 97
96 | 99 | 98 | 97
97 | 99 | 98 | 98
98 | 99 | 99 | 99
99 | 100 | 99 | 99
100 | 100 | 100 | 100
Note: To use this table, first compute the restricted insulation thickness as a fraction of the uncompressed (full) insulation thickness. Then look up the R-value remaining from the appropriate column (Non-uniform Restriction, Batt Non-uniform Restriction, Blown or Uniform Compression, Batt). Example: Assume a section of loose-fill ceiling insulation went from R-25 insulation at a height of 10 inches to a minimum height of 2 inches at the edge of the ceiling. The ratio of minimum to full thickness is 0.20 (2 divided by 10). Look up 0.20 (20 percent), read across to column 3 (Non-uniform Restriction, Blown), and read 50 percent. Therefore, the R-value of the loose-fill insulation over the restricted area would be R-12.5 (50 percent of 25).
(a) Non-uniform restriction is that which occurs between non-parallel planes, such as in the ceiling near the eaves.
(b) Uniform compression is compression between parallel planes, such as that which occurs in a wall.
(d) Air supply ducts within floor cavity. Air supply ducts located within a floor cavity shall be assumed to be heating or cooling the floor cavity to living space temperatures unless the duct is structurally isolated by the framing system or thermally insulated from the rest of the floor cavity with a thermal insulation at least equal to ­R-4.
(e) Air supply ducts within ceiling cavity. Where supply ducts are located in ceiling cavities, the influence of the duct on cavity temperatures shall be considered in calculating envelope heat loss or heat gain.
(f) The supply duct loss (and/or heat gain where applicable—See § 3280.511) shall be calculated using the actual duct surface area and the actual thickness of insulation between the duct and outside of the manufactured home. If there is an air space of at least 1/2 inch between the duct and the insulation, heat loss/gain need not be calculated if the cavity in which the duct is located is assumed to be at living space temperature. The average temperature inside the supply duct, including ducts installed outside the manufactured home, shall be assumed to be 130 F for purposes of calculation of heat loss and 60 F for heat gain.
(g) Return air cavities. Cavities used as return air plenums shall be considered to be at living space temperature.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 78 FR 73984, Dec. 9, 2013]
§ 3280.510
Heat loss certificate.
The manufactured home manufacturer shall permanently affix the following “Certificate” to an interior surface of the home that is readily visible to the homeowner. The “Certificate” shall specify the following:
(a) Heating zone certification. The design zone at which the manufactured home heat loss complies with § 3280.506(a).
(b) Outdoor certification temperature. The lowest outdoor temperature at which the installed heating equipment will maintain a 70 °F temperature inside the home without storm sash or insulating glass for Zones 1 and 2, and with storm sash or insulating glass for Zone 3 and complying with § 3280.508 and § 3280.509.
(c) Operating economy certification temperature. The temperature to be specified for operating economy and energy conservation shall be 20 °F or 30% of the design temperature difference, whichever is greater, added to the temperature specified as the heating system capacity certification temperature without storm windows or insulating glass in Zones 1 and 2 and with storm windows or insulating glass in Zone 3. Design temperature difference is 70° minus the heating system capacity certification temperature in degrees Fahrenheit.

HEATING CERTIFICATE
Home Manufacturer
Plant Location
Home Model

(Include Uo Value Zone Map)
This manufactured home has been thermally insulated to conform with the requirements of the Federal Manufactured Home Construction and Safety Standards for all locations within Uo Value Zone __.
Heating Equipment Manufacturer
Heating Equipment Model
The above heating equipment has the capacity to maintain an average 70F temperature in this home at outdoor temperatures of [see paragraph (b) of this section] F. To maximize furnace operating economy and to conserve energy, it is recommended that this home be installed where the outdoor winter design temperature (97 1/2%) is not higher than [see paragraph (c) of this section] F degrees Fahrenheit.
The above information has been calculated assuming a maximum wind velocity of 15 MPH at standard atmospheric pressure.
(d) The following additional statement must be provided on the heating certificate and data plate required by § 3280.5 when the home is built with a vapor retarder of not greater than one perm (dry cup method) on the exterior side of the insulation: “This home is designed and constructed to be sited only in humid or fringe climate regions as shown on the Humid and Fringe Climate Map.” A reproduction of the Humid and Fringe Climate Map in § 3280.504 is to be provided on the heating certificate and data plate. The map must be not less than 31/2 inch × 21/4 inch in size and may be combined with the Uo Value Zone Map for Manufactured Housing in § 3280.506.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55011, Oct. 25, 1993; 70 FR 72048, Nov. 30, 2005]
§ 3280.511
Comfort cooling certificate and information.
(a) The manufactured home manufacturer shall permanently affix a “Comfort Cooling Certificate” to an interior surface of the home that is readily visible to the home owner. This certificate may be combined with the heating certificate required in § 3280.510. The manufacturer shall comply with one of the following three alternatives in providing the certificate and additional information concerning the cooling of the manufactured home:
(1) Alternative I. If a central air conditioning system is provided by the home manufacturer, the heat gain calculation necessary to properly size the air conditioning equipment shall be in accordance with procedures outlined in chapter 22 of the 1989 ASHRAE Handbook of Fundamentals, with an assumed location and orientation. The following shall be supplied in the Comfort Cooling Certificate:
Air Conditioner Manufacturer
Air Conditioner Model
Certified Capacity ___ BTU/Hr. in accordance with the appropriate Air Conditioning and Refrigeration Institute Standards
The central air conditioning system provided with this home has been sized, assuming an orientation of the front (hitch) end of the home facing ___ and is designed on the basis of a 75 °F indoor temperature and an outdoor temperature of _ °F dry bulb and _ °F wet bulb.

Example Alternate I

COMFORT COOLING CERTIFICATE
Manufactured Home Mfg
Plant Location
Manufactured Home Model
Air Conditioner Manufacturer
Certified Capacity ___ BTU/Hr. in accordance with the appropriate Air Conditioning and Refrigeration Institute Standards.
The central air conditioning system provided with this home has been sized assuming an orientation of the front (hitch end) of the home facing ___. On this basis, the system is designed to maintain an indoor temperature of 75 °F when outdoor temperatures are _ °F dry bulb and _ °F wet bulb.
The temperature to which this home can be cooled will change depending upon the amount of exposure of the windows to the sun's radiant heat. Therefore, the home's heat gains will vary dependent upon its orientation to the sun and any permanent shading provided. Information concerning the calculation of cooling loads at various locations, window exposures and shadings are provided in chapter 22 of the 1989 edition of the ASHRAE Handbook of Fundamentals.
(2) Alternative 2. For each home suitable for a central air cooling system, the manufacturer shall provide the following statement: “This air distribution system of this home is suitable for the installation of a central air conditioning system.”

Example Alternate 2

COMFORT COOLING CERTIFICATE
Manufactured Home Manufacturer
Plant Location
Manufactured Home Model
This air distribution system of this home is suitable for the installation of central air conditioning.
The supply air distribution system installed in this home is sized for Manufactured Home Central Air Conditioning System of up to ___ B.T.U./Hr. rated capacity which are certified in accordance with the appropriate Air Conditioning and Refrigeration Institute Standards. When the air circulators of such air conditioners are rated at 0.3 inch water column static pressure or greater for the cooling air delivered to the manufactured home supply air duct system.
Information necessary to calculate cooling loads at various locations and orientations is provided in the special comfort cooling information provided with this manufactured home.
(3) Alternative 3. If the manufactured home is not equipped with an air supply duct system, or if the manufacturer elects not to designate the home as being suitable for the installation of a central air conditioning system, the manufacturer shall provide the following statement: “This air distribution system of this home has not been designed in anticipation of its use with a central air conditioning system.”

Example Alternate 3

COMFORT COOLING CERTIFICATE
Manufactured Home Mfg
Plant Location
Manufactured Home Model
The air distribution system of this home has not been designed in anticipation of its use with a central air conditioning system.
(b) For each home designated as suitable for central air conditioning the manufacturer shall provide the maximum central manufactured home air conditioning capacity certified in accordance with the ARI Standard 210/240-89 Unitary Air-Conditioning and Air-Source Heat Pump Equipment and in accordance with § 3280.715(a)(3). If the capacity information provided is based on entrances to the air supply duct at other than the furnace plenum, the manufacturer shall indicate the correct supply air entrance and return air exit locations.
(c) Comfort cooling information. For each manufactured home designated, either “suitable for” or “provided with” a central air conditioning system, the manufacturer shall provide comfort cooling information specific to the manufactured home necessary to complete the cooling load calculations. The comfort cooling information shall include a statement to read as follows:
To determine the required capacity of equipment to cool a home efficiently and economically, a cooling load (heat gain) calculation is required. The cooling load is dependent on the orientation, location and the structure of the home. Central air conditioners operate most efficiently and provide the greatest comfort when their capacity closely approximates the calculated cooling load. Each home's air conditioner should be sized in accordance with chapter 22 of the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Handbook of Fundamentals, 1989 Edition, once the location and orientation are known.

Information Provided by the Manufacturer Necessary To Calculate Sensible Heat Gain
Walls (without windows and doors) | U
Ceilings and roofs of light color | U
Ceilings and roofs of dark color | U
Floors | U
Air ducts in floor | U
Air ducts in ceiling | U
Air ducts installed outside the home | U
Information necessary to calculate duct areas.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55012, Oct. 25, 1993]

Subpart G—Plumbing Systems
§ 3280.601
Scope.
Subpart G of this standard covers the plumbing materials, fixtures, and equipment installed within or on manufactured homes. It is the intent of this subpart to assure water supply, drain, waste and vent systems which permit satisfactory functioning and provide for health and safety under all conditions of normal use.
§ 3280.602
Definitions.
The following definitions are applicable to subpart G only:
Accessible, when applied to a fixture, connection, appliance or equipment, means having access thereto, but which may require removal of an access panel or opening of a door.
Air gap (water distribution system) means the unobstructed vertical distance through the free atmosphere between the lowest opening from any pipe or faucet supplying water to a tank, plumbing fixture, water supplied appliances, or other device and the flood level rim of the receptacle.
Backflow means the flow of water or other liquids, mixtures, or substances into the distributing pipes of a potable supply of water from any source or sources other than its intended sources.
Backflow connection means any arrangement whereby backflow can occur.
Backflow preventer means a device or means to prevent backflow.
Branch means any part of the piping system other than a riser, main or stack.
Common vent means a vent connecting at the junction of fixture drains and serving as a vent for more than one fixture.
Continuous vent means a vertical vent that is a continuation of the drain to which it connects.
Continuous waste means a drain from two or more fixtures connected to a single trap.
Critical level means a point established by the testing laboratory (usually stamped on the device by the manufacturer) which determines the minimum elevation above the flood level rim of the fixture or receptacle served on which the device may be installed. When a backflow prevention device does not bear a critical level marking, the bottom of the vacuum breaker, combination valve, or of any such approved or listed device shall constitute the critical level.
Cross connection means any physical connection or arrangement between two otherwise separate systems or sources, one of which contains potable water and the other either water, steam, gas or chemical of unknown or questionable safety whereby there may be a flow from one system or source to the other, the direction of flow depending on the pressure differential between the two systems.
Developed length means that length of pipe measured along the center line of the pipe and fittings.
Diameter, unless otherwise specifically stated, means the nominal (inside) diameter designated commercially.
Drain means a pipe that carries waste, water, or water-borne waste in a drainage system.
Drain connector means the removable extension, consisting of all pipes, fittings and appurtenances, from the drain outlet to the drain inlet serving the manufactured home.
Drain outlet means the lowest end of the main or secondary drain to which a sewer connection is made.
Drainage system means all piping within or attached to the structure that conveys sewage or other liquid waste to the drain outlet, not including the drain connector.
Fixture drain means the drain from the trap of a fixture to the junction of that drain with any other drain pipe.
Fixture supply means the water supply pipe connecting a fixture to a branch water supply pipe or directly to a main water supply pipe.
Flood-level means the level in the receptacle over which water would overflow to the outside of the receptacle.
Flooded means the condition which results when the liquid in a container or receptacle rises to the flood-level.
Flush tank means that portion of a water closet that is designed to contain sufficient water to adequately flush the fixture.
Flush valve means a device located at the bottom of a flush tank for flushing a water closet.
Flushometer tank: means a device integrated within an air accumulator vessel which is designed to discharge a predetermined quantity of water to fixtures for flushing purposes.
Flushometer valve means a device which discharges a predetermined quantity of water to a fixture for flushing purposes and is closed by direct water pressure.
Grade means the fall (slope) of a pipe in reference to a horizontal plane expressed in inches per foot length.
Horizontal branch means any pipe extending laterally, which receives the discharge from one or more fixture drains and connects to the main drain.
Horizontal pipe means any pipe or fitting which makes an angle of not more than 45 degrees with the horizontal.
Individual vent means a pipe installed to vent a fixture drain.
Inlet coupling means the terminal end of the water system to which the water service connection is attached. It may be a swivel fitting or threaded pipe end.
Main means the principal artery of the system to which branches may be connected.
Main drain means the lowest pipe of a drainage system which receives sewage from all the fixtures within a manufactured home and conducts these wastes to the drain outlet.
Main vent means the principal artery of the venting system to which vent branches may be connected.
Mechanical trap vent device means a device that automatically opens to admit air to a fixture drain above the connection of the trap arm so as to prevent siphonage, and closes tightly when the pressure within the drainage system is equal to or greater than atmospheric pressure, so as to prevent the escape of gases from the drainage system into the manufactured home.
Offset means a combination of pipe and/or fittings that brings one section of the pipe out of line but into a line parallel with the other section.
Pitch. See Grade.
Plumbing appliance: means any one of a special class of plumbing fixture which is intended to perform a special plumbing function. Its operation and/or control may be dependent upon one or more energized components, such as motors, control, heating elements, or pressure or temperature-sensing elements. Such fixture may operate automatically through one or more of the following actions: A time cycle, a temperature range, a pressure range, a measured volume or weight, or the fixture may be manually adjusted or controlled by the user or operator.
Plumbing appurtenance: means a manufactured device, or a prefabricated assembly, or an on-the-job assembly of component parts, and which is an adjunct to the basic piping system and plumbing system and plumbing fixtures. An appurtenance demands no additional water supply, nor does it add any discharge load to a fixture or the drainage system.
Plumbing fixtures means receptacles, devices, or appliances which are supplied with water or which receive liquid or liquid-borne wastes for discharge into the drainage system.
Plumbing system means the water supply and distribution pipes; plumbing fixtures, faucets and traps; soil, waste and vent pipes; and water-treating or water-using equipment.
Primary vent. See main vent.
Relief vent means an auxiliary vent which permits additional circulation of air in or between drainage and vent systems.
Secondary vent means any vent other than the main vent or those serving each toilet.
Sewage means any liquid waste containing animal or vegetable matter in suspension or solution, and may include liquids containing chemicals in solution.
Siphonage means the loss of water seal from fixture traps resulting from partial vacuum in the drainage system which may be of either of the following two types, or a combination of the two:
(a) Self-siphonage resulting from vacuum in a fixture drain generated solely by the discharge of the fixture served by that drain, or,
(b) Induced siphonage resulting from vacuum in the drainage system generated by the discharge of one or more fixtures other than the one under observation.
Trap means a fitting or device designed and constructed to provide a liquid seal that will prevent the back passage of air without materially affecting the flow of liquid waste through it.
Trap arm means the portion of a fixture drain between a trap and its vent.
Trap seal means the vertical depth of liquid that a trap will retain.
Vacuum breaker. See backflow preventer.
Vent cap means the device or fitting which protects the vent pipe from foreign substance with an opening to the atmosphere equal to the area of the vent it serves.
Vent system means that part of a piping installation which provides circulation of air within a drainage system.
Vertical pipe means any pipe or fitting which makes an angle of not more than 45 degrees with the vertical.
Water closet drain means that part of the drainage piping which receives the discharge from each individual water closet.
Water connection means the fitting or point of connection for the manufactured home water distribution system designed for connection to a water supply.
Water connector means the removable extension connecting the manufactured home water distribution system to the water supply.
Water distribution system means potable water piping within or permanently attached to the manufactured home.
Wet vent means a vent which also serves as a drain for one or more fixtures.
Wet vented drainage system means the specially designed system of drain piping that also vents one or more plumbing fixtures by means of a common waste and vent pipe.
Whirlpool bathtub means a plumbing appliance consisting of a bathtub fixture which is equipped and fitted with a circulation piping system, pump, and other appurtenances and is so designed to accept, circulate, and discharge bathtub water upon each use.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4584, Feb. 12, 1987; 52 FR 47553, Dec. 15, 1987; 58 FR 55012, Oct. 25, 1993; 78 FR 73984, Dec. 9, 2013]
§ 3280.603
General requirements.
(a) Minimum requirements. Any plumbing system installed in a manufactured home shall conform, at least, with the provisions of this subpart.
(1) General. The plumbing system shall be of durable material, free from defective workmanship, and so designed and constructed as to give satisfactory service for a reasonable life expectancy.
(2) Conservation. Each water closet must not use more than 1.6 gallons of water per flush.
(3) Connection to drainage system. All plumbing, fixtures, drains, appurtenances, and appliances designed or used to receive or discharge liquid waste or sewage shall be connected to the manufactured home drainage system in a manner provided by this standard.
(4) Workmanship. All design, construction, and workmanship shall be in conformance with accepted engineering practices and shall be of such character as to secure the results sought to be obtained by this standard.
(5) Components. Plumbing materials, devices, fixtures, fittings, equipment, appliances, appurtenance, and accessories intended for use in or attached to a manufactured home shall conform to one of the applicable standards referenced in § 3280.604. Where an applicable standard is not referenced, or an alternative recognized standard is utilized, the plumbing component shall be listed by a nationally recognized testing laboratory, inspection agency or other qualified organization as suitable for the intended use.
(6) Prohibited fittings and practices. (i) Drainage or vent piping shall not be drilled and tapped for the purpose of making connections.
(ii) Except as specifically provided elsewhere in this standard, vent pipes shall not be used as waste or drain pipes.
(iii) Fittings, connections, devices, or methods of installation that obstruct or retard the flow of sewage, or air in the drainage or venting systems in an amount greater than the normal frictional resistance to flow shall not be used unless their use is acceptable in this standard or their use is accepted as having a desirable and acceptable function of ultimate benefit to the proper and continued functioning of the plumbing system.
(iv) Cracks, holes, or other imperfections in materials shall not be concealed by welding, brazing, or soldering or by paint, wax, tar, or other leak-sealing or repairing agents.
(v) Piping, fixtures or equipment shall be located so as not to interfere with the normal use or with the normal operation and use of windows, doors or other required facilities.
(vi) Galvanized pipe shall not be bent or welded.
(7) Alignment of fittings. All valves, pipes, and fittings shall be installed in correct relationship to the direction of flow.
(b) Protective requirements. (1) Cutting structural members. Structural members shall not be unnecessarily or carelessly weakened by cutting or notching.
(2) Exposed piping. All piping, pipe threads, hangers, and support exposed to the weather, water, mud, and road hazard, and subject to damage therefrom, shall be painted, coated, wrapped, or otherwise protected from deterioration.
(3) Road damage. Pipes, supports, drains, outlets, or drain hoses shall not extend or protrude in a manner where they could be unduly subjected to damage during transit.
(4) Freezing. All piping and fixtures subject to freezing temperatures shall be insulated or protected to prevent freezing, under normal occupancy. The manufacturer shall provide:
(i) Written installation instructions for the method(s) required for compliance to this section;
(ii) A statement in the installation instructions required by § 3280.306(b), stating that if the heat tape or pipe heating cable is used, it must be listed for use with manufactured homes.
(iii) A receptacle outlet complying with § 3280.806(d)(10).
(5) All piping, except the fixture trap, shall be designed to allow drainage.
(6) Rodent resistance. All exterior openings around piping and equipment shall be sealed to resist the entrance of rodents.
(7) Piping and electrical wiring shall not pass through the same holes in walls, floors or roofs. Plastic piping shall not be exposed to heat in excess of manufacturers recommendation or radiation from heat producing appliances.
[40 FR 58752, Dec. 18, 1975, as amended at 42 FR 54383, Oct. 5, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55012, Oct. 25, 1993; 78 FR 73985, Dec. 9, 2013]
§ 3280.604
Materials.
(a) Minimum standards. Materials, devices, fixtures, fittings, equipment, appliances, appurtenances and accessories shall conform to one of the standards in the following table and be free from defects. Where an appropriate standard is not indicated in the table or a standard not indicated in the table is preferred, the item may be used if it is listed. A listing is also required when so specified in other sections of this subpart.
(b) Where more than one standard is referenced for a particular material or component, compliance with only one of those standards is acceptable. Exceptions:
(1) When one of the reference standards requires evaluation of chemical, toxicity or odor properties which are not included in the other standard, then conformance to the applicable requirements of each standard shall be demonstrated;
(2) When a plastic material or component is not covered by the Standards in the following table, it must be certified as non-toxic in accordance with ANSI/NSF 61-2001, Drinking water system components—Health effects.

Ferrous Pipe and Fittings
Gray Iron Threaded Fittings—ANSI/ASME B16.4-1992.
Malleable Iron Threaded Fittings—ANSI/ASME B16.3-1992.
Material and Property Standard for Special Cast Iron Fittings—IAPMO PS 5-84.
Welding and Seamless Wrought Steel Pipe—ANSI/ASME B36.10-1979.
Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless—ASTM A53-93.
Pipe Threads, General Purpose (Inch)—ANSI/ASME B1.20.1-1983.
Standard Specification for Cast Iron Soil Pipe and Fittings—ASTM A74-92.
Standard Specification for Hubless Cast Iron Soil Pipe and Fittings for Sanitary and Storm Drain, Waste, and Vent Piping Applications—CISPI-301-90.

Nonferrous Pipe and Fittings
Standard Specification for Seamless Copper Pipe, Standard Sizes—ASTM B42-93.
Standard Specification for General Requirements for Wrought Seamless Copper and Copper-Alloy Tube—ASTM B251-93.
Standard Specification for Seamless Copper Water Tube—ASTM B88-93.
Standard Specification for Copper Drainage Tube (DWV)—ASTM B306-92.
Wrought Copper and Copper Alloy Solder-Joint Pressure Fitting—ASME/ANSI B16.22-1989.
Wrought Copper and Wrought Copper Alloy Solder-Joint Drainage Fittings-DWV—ASME/ANSI B16.29-1986.
Cast Copper Alloy Solder-Joint Pressure Fittings—ANSI B16.18-1984.
Cast Copper Alloy Solder-Joint Drainage Fittings-DWV—ASME B16.23-1992.
Cast Copper Alloy Fittings for Flared Copper Tubes—ASME/ANSI B16.26-1988.
Standard Specification for Seamless Red Brass Pipe, Standard Sizes—ASTM B43-91.
Cast Bronze Threaded Fittings, Classes 125 and 250—ANSI/ASME B16.15-1985.

Plastic Pipe and Fittings
Standard Specification Acrylonitrile-Butadiene-Styrene (ABS) Schedule 40 Plastic Drain, Waste, and Vent Pipe and Fittings—ASTM D2661-91.
Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic Drain, Waste, and Vent Pipe and Fittings—ASTM D2665-91b.
Standard Specification for Drain, Waste, and Vent (DWV) Plastic Fittings Patterns—ASTM D3311-92.
Standard Specification for Acrylonitrile-Butadiene-Styrene (ABS) Schedule 40, Plastic Drain, Waste, and Vent Pipe With a Cellular Core—ASTM F628-91.
Standard Specification for Chlorinated Poly (Vinyl Chloride) (CPVC) Plastic Hot- and Cold-Water Distribution Systems—ASTM D2846-92.
Standard Specification for Polybutylene (PB) Plastic Hot- and Cold-Water Distribution Systems—ASTM D3309-92a.
Plastic Piping Components and Related Materials—ANSI/NSF 14-1990.
Standard Specification for Crosslinked Polyethylene (PEX) Tubing—ASTM F876-10 (incorporated by reference, see § 3280.4).
Standard Specification for Crosslinked Polyethylene (PEX) Plastic Hot- and Cold-Water Distribution Systems—ASTM F877-07 (incorporated by reference, see § 3280.4).

Miscellaneous
Standard Specification for Rubber Gaskets for Cast Iron Soil Pipe and Fittings, ASTM C564-97 (incorporated by reference, see § 3280.4).
Backflow Valves—ANSI A112.14.1-1975.
Plumbing Fixture Setting Compound—TTP 1536A-1975.
Material and Property Standard for Cast Brass and Tubing P-Traps—IAPMO PS 2-89.
Relief Valves for Hot Water Supply Systems, ANSI Z21.22-1999 (incorporated by reference, see § 3280.4).
Standard Specification for Solvent Cement for Acrylonitrile-Butadiene-Styrene (ABS) Plastic Pipe and Fittings—ASTM D2235-88.
Standard Specification for Solvent Cements for Poly (Vinyl Chloride) (PVC) Plastic Piping Systems—ASTM D2564-91a.
Specification for Neoprene Rubber Gaskets for HUB and Spigot Cast Iron Soil Pipe and Fittings—CISPI-HSN-85.
Plumbing System Components for Manufactured Homes and Recreational Vehicles—ANSI/NSF 24-1988.
Material and Property Standard for Diversion Tees and Twin Waste Elbow—IAPMO PS 9-84.
Material and Property Standard for Flexible Metallic Water Connectors—IAPMO PS 14-89.
Material and Property Standard for Dishwasher Drain Airgaps—IAPMO PS 23-89.
Material and Property Standards for Backflow Prevention Assemblies—IAPMO PS 31-91.
Performance Requirements for Air Admittance Valves for Plumbing Drainage Systems, Fixture and Branch Devices—ASSE Standard #1051, 1990 Revised: 1996/ANSI 1998.
Drinking Water System Components-Health Effects—ANSI/NSF 61-2001.

Plumbing Fixtures
Plumbing Fixtures (General Specifications)—FS WW-P-541E/GEN-1980.
Vitreous China Plumbing Fixtures—ANSI/ASME A112.19.2(M)-1990.
Enameled Cast Iron Plumbing Fixtures—ANSI/ASME A112.19.1M-1987.
Porcelain Enameled Formed Steel Plumbing Fixtures—ANSI/ASME A112.19.4(M)-1984.
Plastic Bathtub Units with Addenda Z124.1a-1990 and Z124.16-1991—ANSI Z124.1-1987.
Standard for Porcelain Enameled Formed Steel Plumbing Fixtures—IAPMO TSC 22-85.
Plastic Shower Receptors and Shower Stalls with Addendum Z124.2a-1990—ANSI Z124.2-1987.
Stainless Steel Plumbing Fixtures (Designed for Residential Use)—ANSI/ASME A112.19.3M-1987.
Material and Property Standard for Drains for Prefabricated and Precast Showers—IAPMO PS 4-90.
Plastic Lavatories with Addendum Z124.3a-1990—ANSI Z124.3-1986.
Standard for Safety Glazing Materials used in Buildings—Safety Performance Specifications and Methods of Test, ANSI Z97.1-2004 (incorporated by reference, see § 3280.4).
Water Heater Relief Valve Drain Tubes—ASME A112.4.1-1993.
Flexible Water Connectors—ASME A112.18.6-1999.
Performance Requirements for Backflow Protection Devices and Systems in Plumbing Fixture Fittings—ASME A112.18.3M-1996.
Non-Vitreous Ceramic Plumbing Fixtures—ASME A112.19.9M-1991.
Dual Flush Devices for Water Closets—ASME A119.19.10-1994.
Deck Mounted Bath/Shower Transfer Valves with Integral Backflow Protection—ASME A112.18.7-1999.
Plastic Fittings for Connecting Water Closets to the Sanitary Drainage System—ASME A112.4.3-1999.
Hydraulic Performance Requirements for Water Closets and Urinals, ASME A112.19.6-1995.
Plumbing Fixture Fittings—ASME/ANSI A112.18.1M-1989.
Trim for Water Closet, Bowls, Tanks, and Urinals—ANSI A112.19.5-1979.
Plastic Water Closets, Bowls, and Tanks with Addenda Z124.4a-1990—ANSI Z124.4-1986.
ANSI Z124.5, Plastic Toilet (Water Closets) Seats, 1997.
ANSI Z124.7, Prefabricated Plastic Spa Shells, 1997.
Whirlpool Bathtub Appliances—ASME/ANSI A112.19.7M-1987.
ANSI Z-124.9, Plastic Urinal Fixtures, 1994.
Performance Requirements for Individual Thermostatic Pressure Balancing and Combination Control for Bathing Facilities—ASSE 1016-1988 (ANSI 1990).
Performance Requirements for Pressurized Flushing Devices (Flushometers) for Plumbing Fixtures—ASSE 1037-1990 (ANSI-1990).
Performance Requirements for Water Closet Flush Tank Fill Valves (Ballcocks)—ASSE 1002 Revision 5-1986 (ANSI/ASSE-1979).
Performance Requirements for Hand-held Showers—ASSE 1014-1989 (ANSI-1990).
Hydrants for Utility and Maintenance Use—ANSI/ASME A112.21.3M-1985.
Performance Requirements for Home Laundry Equipment—ASSE 1007-1986.
Performance Requirements for Hot Water Dispensers, Household Storage Type Electrical—ASSE 1023, (ANSI/ASSE-1979).
Plumbing Requirements for Residential Use (Household) Dishwashers—ASSE 1006, (ASSE/ANSI-1986).
Performance Requirements for Household Food Waste Disposer Units—ASSE 1008-1986.
Performance Requirements for Temperature Activated Mixing Valves for Primary Domestic Use—ASSE 1017-1986.
Water Hammer Arresters—ANSI A112.26.1-1969 (R 1975).
Suction Fittings for Use in Swimming Pools, Wading Pools, Spas, Hot Tubs, and Whirlpool Bathtub Appliances—ASME/ANSI A112.19.8M-1989.
Air Gaps in Plumbing Systems—ASME A112.1.2-1991.
Performance Requirements for Diverters for Plumbing Faucets with Hose Spray, Anti-Siphon Type, Residential Applications—ASSE 1025 (ANSI/ASSE-1978).
Performance Requirements for Pipe Applied Atmospheric Type Vacuum Breakers—ASSE 1001 (ASSE/ANSI-1990).
Performance Requirements for Hose Connection Vacuum Breakers—ASSE 1011-1981 (ANSI-1982).
Performance Requirements for Wall Hydrants, Frost Proof Automatic Draining, Anti-Backflow Types—ANSI/ASSE 1019-1978.
Performance Requirements for Automatic Compensating Values for Individual Shower and Tub/Shower Combinations, approved January 2005 ASSE 1016-2005 (incorporated by reference, see § 3280.4).
Performance Requirements for Water Temperature Limiting Devices, approved February 2004, ASSE 1070-2004 (incorporated by reference, see § 3280.4).
[58 FR 55013, Oct. 25, 1993, as amended at 70 FR 72048, Nov. 30, 2005; 78 FR 73985, Dec. 9, 2013; 79 FR 31863, June 3, 2014]
§ 3280.605
Joints and connections.
(a) Tightness. Joints and connections in the plumbing system shall be gastight and watertight for the pressures required under testing procedures.
(b) Assembling of pipe. All joints and connections shall be correctly assembled for tightness. Pipe threads shall be fully engaged with the threads of the fitting. Plastic pipe and copper tubing shall be inserted to the full depth of the solder cup or welding sockets of each fitting. Pipe threads and slip joints shall not be wrapped with string, paper, putty, or similar fillers.
(c) Threaded joints. Threads for screw pipe and fittings shall conform to the approved or listed standard. Pipe ends shall be reamed out to size of bore. All burrs, chips, cutting oil and foreign matter shall be removed. Pipe joint cement or thread lubricant shall be of approved type and applied to male threads only.
(d) Solder joints. Solder joints for tubing shall be made with approved or listed solder type fittings. Surfaces to be soldered shall be cleaned bright. The joints shall be properly fluxed with noncorrosive paste type flux and, for manufactured homes to be connected to a public water system, made with solder having not more than 0.2 percent lead.
(e) Plastic pipe, fittings and joints. Plastic pipe and fittings shall be joined by installation methods recommended by the manufacturer or in accordance with the provisions of a recognized, approved, or listed standard.
(f) Union joints. Metal unions in water piping shall have metal-to-metal ground seats.
(g) Flared joints. Flared joints for soft-copper water tubing shall be made with approved or listed fittings. The tubing shall be expanded with a proper flaring tool.
(h) Cast iron soil pipe joints. Approved or listed cast iron pipe may be joined as follows:
(1) Approved or listed hub-less pipe and fittings must be permitted to be joined with listed couplings or adapters, per the manufacturer's recommendations.
(2) Hub and plain-end soil pipe may be joined by compression fittings per the manufacturer's recommendation.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 53 FR 23611, June 23, 1988; 78 FR 73985, Dec. 9, 2013]
§ 3280.606
Traps and cleanouts.
(a) Traps—(1) Traps required. Each plumbing fixture, except listed toilets, shall be separately trapped by approved water seal “P” traps. All traps shall be effectively vented.
(2) Combination Fixtures. For the purposes of drainage and ventilation requirements, a two- or three-compartment sink, up to three single sinks, or up to three lavatories may be connected to one “P” trap and considered as a single fixture, so long as the sinks and lavatories are in the same room, have waste outlets not more than 30 inches apart, and have flood level rims at the same level. The “P” trap must be installed at the center fixture when three such fixtures are installed.
(3) Prohibited traps. A trap which depends for its seal upon concealed interior partitions shall not be used. Full “S” traps, bell traps, drum traps, crown-vented traps, and running traps are prohibited. Fixtures shall not be double-trapped.
(4) Material and design. Each trap shall be self-cleaning with a smooth and uniform interior waterway. Traps shall be manufactured of cast iron, cast brass, or drawn brass tubing of not less than No. 20 Brown and Sharpe gage, or approved or listed plastic, or other approved or listed material. Union joints for a trap shall be beaded to provide a shoulder for the union nut. Each trap shall have the manufacturer's name stamped or cast in the body of the trap, and each tubing trap shall show the gage of the tubing.
(5) Trap seal. Each “P” trap shall have a water seal of not less than 2 inches and not more than 4 inches and shall be set true to its seal.
(6) Size. Traps shall be not less than 11/4 inches in diameter. A trap shall not be larger than the waste pipe to which it is connected.
(7) Location. Each trap shall be located as close to its vent and to its fixture outlet as structural conditions will permit.
(8) Length of tailpiece. The vertical distance from a trap to the fixture outlet shall not exceed 24 inches.
(9) Installation. (i) Grade of trap arm. The piping between a “P” trap and the fixture tee or the vented waste line shall be graded 1/4 inch per foot towards the vent and in no event shall have a slope greater than its diameter. The vent opening at fixture tees shall not be below the weir of the “P” trap outlet.
(ii) Trap arm offset. The piping between the “P” trap and vent may change direction or be offset horizontally with the equivalent of no more than 180 degrees total change in direction with a maximum of 90 degrees by any one fitting.
(iii) Concealed traps. Traps with mechanical joints shall be accessible for repair and inspection.
(iv) Removability of traps, etc. Traps shall be designed and installed so the “U” bend is removable without removing the strainers from the fixture. Continuous waste and tail pieces which are permanently attached to the “U” bend shall also be removable without removing the strainer from the fixture.
(b) Cleanout openings—(1) Location of cleanout fittings. (i) Cleanouts shall be installed if the drainage system cannot be cleaned through fixtures, drains, or vents. Cleanouts shall also be provided when fittings of more than 45 degrees are used to affect an offset except where long turn ells are used which provide sufficient “sweep” for cleaning.
(ii) A full size cleanout shall be installed at the upper end of any section of drain piping which does not have the required minimum slope of 1/4 inch per foot grade.
(iii) A cleaning tool shall not be required to pass through more than 360 degrees of fittings, excluding removable “P” traps, to reach any part of the drainage system. Water closets may be removed for drainage system access.
(2) Access to cleanouts. Cleanouts shall be accessible through an unobstructed minimum clearance of 12 inches directly in front of the opening. Each cleanout fitting shall open in a direction opposite to the flow or at right angles to the pipe. Concealed cleanouts that are not provided with access covers shall be extended to a point above the floor or outside of the manufactured home, with pipe and fittings installed, as required, for drainage piping without sags and pockets.
(3) Material. Plugs and caps shall be brass or approved or listed plastic, with screw pipe threads.
(4) Design. Cleanout plugs shall have raised heads except that plugs at floor level shall have counter-sunk slots.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55014, Oct. 25, 1993; 78 FR 73985, Dec. 9, 2013]
§ 3280.607
Plumbing fixtures.
(a) General requirements—(1) Quality of fixtures. Plumbing fixtures shall have smooth impervious surfaces, be free from defects and concealed fouling surfaces, be capable of resisting road shock and vibration, and shall conform in quality and design to listed standards. Fixtures shall be permanently marked with the manufacturer's name or trademark.
(2) Strainers. The waste outlet of all plumbing fixtures, other than toilets, shall be equipped with a drain fitting that will provide an adequate unobstructed waterway.
(3) Fixture Connections. Fixture tailpieces and continuous wastes in exposed or accessible locations must be of not less than No. 20 Brown and Sharpe gauge seamless drawn-brass tubing or other approved pipe or tubing materials. Inaccessible fixture connections must be constructed according to the requirements for drainage piping. The diameter of each fixture tailpiece, continuous waste, or waste and overflow must be not less than:
(i) 11/2 inches, for sinks of two or more compartments, dishwashers, clothes washing machines, laundry tubs, bathtubs, and showers; and
(ii) Not less than 11/4 inches for lavatories or single compartment sinks having a 2-inch maximum drain opening.
(4) Concealed connections. Concealed slip joint connections shall be provided with adequately sized unobstructed access panels and shall be accessible for inspection and repair.
(5) Directional fitting. An approved or listed “Y” or other directional-type branch fitting shall be installed in every tailpiece or continuous waste that receives the discharge from food waste disposal units, dishwashing, or other force-discharge fixture or appliance. (See also § 3280.607(b)(4)(ii).)
(6) Water conservation. All lavatory faucets, showerheads, and sink faucets must not exceed a flow of 2.5 gallons per minute (gpm).
(b) Fixtures—(1) Spacing. All plumbing fixtures shall be so installed with regard to spacing as to be reasonably accessible for their intended use.
(2) Water closets. (i) Water closets shall be designed and manufactured according to approved or listed standards and shall be equipped with a water flushing device capable of adequately flushing and cleaning the bowl at each operation of the flushing mechanism.
(ii) Water closet flushing devices shall be designed to replace the water seal in the bowl after each operation. Flush valves, flushometer valves, flushometer tanks and ballcocks shall operate automatically to shut off at the end of each flush or when the tank is filled to operating capacity.
(iii) All water closets must be low consumption (1.6 gallons per flush (gpf)) closets.
(iv) Flush tanks shall be fitted with an overflow pipe large enough to prevent flooding at the maximum flow rate of the ball cock. Overflow pipes shall discharge into the toilet, through the tank.
(v) Floor Connection. Water closets must be securely bolted to an approved flange or other approved fitting that is secured to the floor by means of corrosion-resistant screws. The bolts must be of solid brass or other corrosion-resistant material and must not be less than 1/4 inch in diameter. A watertight seal must be made between the water closet and flange or other approved fitting by use of a gasket, sealing compound, or listed connector device.
(vi) Floor connection. Water closets shall be securely bolted to an approved flange or other approved fitting which is secured to the floor by means of corrosion-resistant screws. The bolts shall be of solid brass or other corrosion-resistant material and shall be not less than one-fourth inch in diameter. A watertight seal shall be made between the water closet and flange or other approved fitting by use of a gasket or sealing compound.
(3) Shower compartment. (i) Each compartment stall shall be provided with an approved watertight receptor with sides and back extending at least 1 inch above the finished dam or threshold. In no case shall the depth of a shower receptor be less than 2 inches or more than 9 inches measured from the top of the finished dam or threshold to the top of the drain. The wall area shall be constructed of smooth, noncorrosive, and nonabsorbent waterproof materials to a height not less than 6 feet above the bathroom floor level. Such walls shall form a watertight joint with each other and with the bathtub, receptor or shower floor. The floor of the compartment shall slope uniformly to the drain at not less than one-fourth nor more than one-half inch per foot.
(ii) The joint around the drain connection shall be made watertight by a flange, clamping ring, or other approved listed means.
(iii) Shower doors and tub and shower enclosures shall be constructed so as to be waterproof and, if glazed, glazing shall comply with the Standard for Safety Glazing Materials used in Buildings—Safety Performance Specifications and Methods of Test, ANSI Z97.1-2004 (incorporated by reference, see § 3280.4).
(iv) Prefabricated plumbing fixtures shall be approved or listed.
(v) Shower and tub-shower combination valves must be balanced pressure, thermostatic, or combination mixing valves that conform to the requirements of ASSE 1016-2005, Performance Requirements for Automatic Compensating Valves for Individual Shower and Tub/Shower Combinations (incorporated by reference, see § 3280.4). Such valves must be equipped with handle position stops that are adjustable in accordance with the valve manufacturer's instructions and to a maximum setting of 120 °F. Hot water supplied to bathtubs and whirlpool bathtubs are to be limited to a temperature of not greater than 120 °F by a water temperature limiting device that conforms to the requirements of ASSE 1070-2004, Performance Requirements for Water Temperature Limiting Devices (incorporated by reference, see § 3280.4).
(4) Dishwashing machines. (i) A dishwashing machine must discharge its waste through a fixed air gap installed above the machine, through a high loop as specified by the dishwashing machine manufacturer, or into an open standpipe receptor with a height greater than the washing compartment of the machine. When a standpipe is used, it must be at least 18 inches, but not more than 30 inches, above the trap weir. The drain connections from the air gap or high loop are permitted to connect to an individual trap to a directional fitting installed in the sink tailpiece or to an opening provided on the inlet side of a food waste disposal unit.
(ii) Drain from a dishwashing machine shall not be connected to a sink tailpiece, continuous waste line, or trap on the discharge side of a food waste disposal unit.
(5) Clothes washing machines. (i) Clothes washing machines shall drain either into a properly vented trap, into a laundry tub tailpiece with watertight connections, into an open standpipe receptor, or over the rim of a laundry tub.
(ii) Standpipes must be either 11/2 inch diameter minimum nominal iron pipe size, 11/2 inch diameter nominal brass tubing of not less than No. 20 Brown and Sharp gauge, or 11/2 inch diameter approved plastic materials. Receptors must discharge into a vented trap or must be connected to a laundry tub appliance by means of an approved or listed directional fitting. Each standpipe must extend not less than 18 inches or more than 42 inches above its trap and must terminate in an accessible location no lower than the top of the clothes washing machine. A removable, tight-fitting cap or plug must be installed on the standpipe when the clothes washer is not provided.
(iii) Clothes washing machine drain shall not be connected to the tailpiece, continuous waste, or trap of any sink or dishwashing machine.
(c) Installation—(1) Access. Each plumbing fixture and standpipe receptor shall be located and installed in a manner to be accessible for usage, cleaning, repair and replacement. Access to diverter valves and other connections from the fixture hardware is not required.
(2) Alignment. Fixtures shall be set level and in true alignment with adjacent walls. Where practical, piping from fixtures shall extend to nearest wall.
(3) Brackets. Wall-hung fixtures shall be rigidly attached to walls by metal brackets or supports without any strain being transmitted to the piping connections. Flush tanks shall be securely fastened to toilets or to the wall with corrosive-resistant materials.
(4) Tub supports. Bathtub rims at wall shall be supported on metal hangers or on end-grain wood blocking attached to the wall unless otherwise recommended by the manufacturer of the tub.
(5) Fixture fittings. Faucets and diverters shall be installed so that the flow of hot water from the fittings corresponds to the left-hand side of the fitting.
(6) Hydromassage bathtub—(i) Access panel. A door or panel of sufficient size must be installed to provide access to the pump for repair or replacement.
(ii) Piping drainage. The circulation pump must be accessibly located above the crown weir of the trap. The pump drain line must be properly sloped to drain the volute after fixture use.
(iii) Piping. Hydromassage bathtub circulation piping must be installed to be self-draining.
(iv) Electrical. Wiring must comply with Articles 680.70, 680.71, and 680.72 of the National Electrical Code, NFPA No. 70-2005.
[40 FR 58752, Dec. 18, 1975, as amended at 42 FR 961, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4586, Feb. 12, 1987; 58 FR 55014, Oct. 25, 1993; 70 FR 72049, Nov. 30, 2005; 71 FR 19639, Apr. 17, 2006; 78 FR 73985, Dec. 9, 2013; 79 FR 31863, June 3, 2014]
§ 3280.608
Hangers and supports.
(a) Strains and stresses. Piping in a plumbing system shall be installed without undue strains and stresses, and provision shall be made for expansion, contraction, and structural settlement.
(b) Piping supports. Piping shall be secured at sufficiently close intervals to keep the pipe in alignment and carry the weight of the pipe and contents. Unless otherwise stated in the standards for specific materials shown in the table in § 3280.604(a), or unless specified by the pipe manufacturer, plastic drainage piping shall be supported at intervals not to exceed 4 feet and plastic water piping shall be supported at intervals not to exceed 3 feet.
(c) Hangers and anchors. (1) Hangers and anchors shall be of sufficient strength to support their proportional share of the pipe alignments and prevent rattling.
(2) Piping shall be securely attached to the structure by hangers, clamps, or brackets which provide protection against motion, vibration, road shock, or torque in the chassis.
(3) Hangers and straps supporting plastic pipe shall not compress, distort, cut or abrade the piping and shall allow free movement of the pipe.
§ 3280.609
Water distribution systems.
(a) Water supply—(1) Supply piping. Piping systems shall be sized to provide an adequate quantity of water to each plumbing fixture at a flow rate sufficient to keep the fixture in a clean and sanitary condition without any danger of backflow or siphonage. (See table in § 3280.609(f)(1)). The manufacturer shall include in his written installation instructions that the manufactured home has been designed for an inlet water pressure of 80 psi, and a statement that when the manufactured home is to be installed in areas where the water pressure exceeds 80 psi, a pressure reducing valve should be installed.
(2) Hot water supply. Each manufactured home equipped with a kitchen sink, and bathtub and/or shower shall be provided with a hot water supply system including a listed water heater.
(b) Water outlets and supply connections—(1) Water connection. Each manufactured home with a water distribution system shall be equipped with a 3/4 inch threaded inlet connection. This connection shall be tagged or marked “Fresh Water Connection” (or marked “Fresh Water Fill”). A matching cap or plug shall be provided to seal the water inlet when it is not in use, and shall be permanently attached to the manufactured home or water supply piping. When a master cold water shutoff full flow valve is not installed on the main feeder line in an accessible location, the manufacturer's installation instructions shall indicate that such a valve is to be installed in the water supply line adjacent to the home. When a manufactured home includes expandable rooms or is composed of two or more units, fittings or connectors designed for such purpose shall be provided to connect any water piping. When not connected, the water piping shall be protected by means of matching threaded caps or plugs.
(2) Prohibited connections. (i) The installation of potable water supply piping or fixture or appliance connections shall be made in a manner to preclude the possibility of backflow.
(ii) No part of the water system shall be connected to any drainage or vent piping.
(3) Rim outlets. The outlets of faucets, spouts, and similar devices shall be spaced at least 1 inch above the flood level of the fixture.
(4) Appliance connections. Water supplies connected to clothes washing or dishwashing machines shall be protected by an approved or listed fixed air gap provided within the appliance by the manufacturer.
(5) Flushometer valves or manually operated flush valves. An approved or listed vacuum breaker shall be installed and maintained in the water supply line on the discharge side of a water closet flushometer valve or manually operated flush valve. Vacuum breakers shall have a minimum clearance of 6 inches above the flood level of the fixture to the critical level mark unless otherwise permitted in their approval.
(6) Flush tanks. Water closet flush tanks shall be equipped with an approved or listed anti-siphon ball cock which shall be installed and maintained with its outlet or critical level mark not less than 1 inch above the full opening of the overflow pipe.
(7) Hose bibbs. When provided, all exterior hose bibbs and laundry sink hose connections must be protected by a listed nonremovable backflow prevention device. This requirement is not applicable to hose connections provided for automatic washing machines with built-in backflow prevention or water heater drain valves.
(8) Flushometer tanks. Flushometer tanks must be equipped with an approved air gap or vacuum breaker assembly that is located above the flood-level rim above the fixture.
(c) Water heater safety devices—(1) Relief valves. (i) All water heaters shall be installed with approved and listed fully automatic valve or valves designed to provide temperature and pressure relief.
(ii) Any temperature relief valve or combined pressure and temperature relief valve installed for this purpose shall have the temperature sensing element immersed in the hottest water within the upper 6 inches of the tank. It shall be set to start relieving at a pressure of 150 psi or the rated working pressure of the tank whichever is lower and at or below a water temperature of 210 °F.
(iii) Relief valves shall be provided with full-sized drains, with cross sectional areas equivalent to that of the relief valve outlet, which shall be directed downward and discharge beneath the manufactured home. Drain lines shall be of a material listed for hot water distribution and shall drain fully by gravity, shall not be trapped, and shall not have their outlets threaded, and the end of the drain shall be visible for inspection.
(d) Materials—(1) Piping material. Water pipe shall be of standard weight brass, galvanized wrought iron, galvanized steel, Type K, L or M copper tubing, approved or listed plastic or other approved or listed material.
(i) Plastic piping. All plastic water piping and fittings in manufactured homes must be listed for use with hot water.
(ii) [Reserved]
(2) Fittings. Appropriate fittings shall be used for all changes in size and where pipes are joined. The material and design of fittings shall conform to the type of piping used. Special consideration shall be given to prevent corrosion when dissimilar metals are joined.
(i) Fittings for screw piping shall be standard weight galvanized iron for galvanized iron and steel pipe, and of brass for brass piping. They shall be installed where required for change in direction, reduction of size, or where pipes are joined together.
(ii) Fittings for copper tubing shall be cast brass or drawn copper (sweat-soldered) or shall be approved or listed fittings for the purpose intended.
(3) Prohibited material. Used piping materials shall not be permitted. Those pipe dopes, solder, fluxes, oils, solvents, chemicals, or other substances that are toxic, corrosive, or otherwise detrimental to the water system shall not be used. In addition, for those manufactured homes to be connected to a public water system, all water piping shall be lead-free (as defined in section 109(c)(2) of the Safe Drinking Water Act Amendments of 1986) with solders and flux containing not more than 0.2 percent lead and pipes and pipe fittings containing not more than 8.0 percent lead.
(e) Installation of piping—(1) Minimum requirement. All piping equipment, appurtenances, and devices shall be installed in workmanlike manner and shall conform with the provisions and intent of this standard.
(2) Screw pipe. Iron pipe-size brass or galvanized iron or steel pipe fittings shall be joined with approved or listed standard pipe threads fully engaged in the fittings. Pipe ends shall be reamed to the full bore of the pipe. Pipe-joint compound shall be insoluble in water, shall be nontoxic and shall be applied to male threads only.
(3) Solder fittings. Joints in copper water tubes shall be made by the appropriate use of approved cast brass or wrought copper fittings, properly soldered together. The surface to be soldered shall be thoroughly cleaned bright mechanically. The joints shall be properly fluxed and made with a solder that contains no more than 0.2 percent lead.
(4) Flared fittings. A flaring tool shall be used to shape the ends of flared tubing to match the flare of fittings.
(5) Plastic pipe and fittings. Plastic pipe and fittings shall be joined by installation methods recommended by the manufacturer or in accordance with provisions of a listed standard.
(f) Size of water supply piping—(1) Minimum size. The size of water supply piping and branch lines shall not be less than sizes shown in the following table:
Minimum Size Tubing and Pipe for Water Distribution Systems
Number of fixtures | Tubing (nominal) | Diameter (inches) | Outer diameter (inches) | Pipe iron pipe size (inches)
1 | *1/4 | 3/8 | 1/2
2 | 3/8 | 1/2 | 1/2
3 | 1/2 | 5/8 | 1/2
4 | 1/2 | 5/8 | 1/2
5 or more | 3/4 | 7/8 | 3/4
*6 ft maximum length.
Exceptions to table: 3/8 inch nominal diameter or 1/2 inch OD minimum size for clothes washing or dishwashing machines, unless larger size is recommended by the fixture manufacturer. 1/2 inch nominal diameter or 5/8 inch OD minimum size for flushometer or metering type valves unless otherwise specified in their listing. No galvanized screw piping shall be less than 1/2 inch iron pipe size.
(2) Sizing procedure. Both hot and cold water piping systems shall be computed by the following method:
(i) Size of branch. Start at the most remote outlet on any branch of the hot or cold water piping and progressively count towards the water service connection, computing the total number of fixtures supplied along each section of piping. Where branches are joined together, the number of fixtures on each branch shall be totalled so that no fixture is counted twice. Following down the left-hand column of the preceding table a corresponding number of fixtures will be found. The required pipe or tubing size is indicated in the other columns on the same line.
(ii) A water heater, food waste disposal unit, evaporative cooler or ice maker shall not be counted as a water-using fixture when computing pipe sizes.
(g) Line valves. Valves, when installed in the water supply distribution system (except those immediately controlling one fixture supply) and when fully opened, shall have a cross-sectional area of the smallest orifice or opening, through which the water flows, at least equal to the cross-sectional area of the nominal size of the pipe in which the valve is installed.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4586, Feb. 12, 1987; 53 FR 23611, June 23, 1988; 58 FR 55014, Oct. 25, 1993; 78 FR 73986, Dec. 9, 2013]
§ 3280.610
Drainage systems.
(a) General. (1) Each fixture directly connected to the drainage system shall be installed with a water seal trap (§ 3280.606(a)).
(2) The drainage system shall be designed to provide an adequate circulation of air in all piping with no danger of siphonage, aspiration, or forcing of trap seals under conditions of ordinary use.
(b) Materials—(1) Pipe. Drainage piping must be standard weight galvanized steel, brass, copper tube DWV, listed Scheduled 40 ABS plastic, listed Scheduled 40 PVC plastic, cast iron, or other listed or approved materials.
(2) Fittings. Drainage fittings shall be recessed drainage pattern with smooth interior waterways of the same diameter as the piping and shall be of a material conforming to the type of piping used. Drainage fittings shall be designed to provide for a 1/4 inch per foot grade in horizontal piping.
(i) Fittings for screw pipe shall be cast iron, malleable iron, brass, or listed plastic with standard pipe threads.
(ii) Fittings for copper tubing shall be cast brass or wrought copper.
(iii) Socket-type fittings for plastic piping shall comply with listed standards.
(iv) Brass or bronze adaptor or wrought copper fittings shall be used to join copper tubing to threaded pipe.
(c) Drain outlets. (1) Each manufactured home shall have only one drain outlet.
(2) Clearance from drain outlet. The drain outlet shall be provided with a minimum clearance of 3 inches in any direction from all parts of the structure or appurtenances and with not less than 18 inches unrestricted clearance directly in front of the drain outlet.
(3) Drain connector. The drain connector shall not be smaller than the piping to which it is connected and shall be equipped with a water-tight cap or plug matching the drain outlet. The cap or plug shall be permanently attached to the manufactured home or drain outlet.
(4) The drain outlet and drain connector shall not be less than 3 inches inside diameter.
(5) Preassembly of drain lines. Section(s) of the drain system, designed to be located underneath the home, are not required to be factory installed when the manufacturer designs the system for site assembly and also provides all materials and components, including piping, fittings, cement, supports, and instructions necessary for proper site installation.
(d) Fixture connections. Drainage piping shall be provided with approved or listed inlet fittings for fixture connections, correctly located according to the size and type of fixture to be connected.
(1) Water closet connection. The drain connection for each water closet shall be 3 inches minimum inside diameter and shall be fitted with an iron, brass, or listed plastic floor flange adaptor ring securely screwed, soldered or otherwise permanently attached to the drain piping, in an approved manner and securely fastened to the floor.
(2) [Reserved]
(e) Size of drainage piping. Fixture drains must be sized as follows:
(1) Fixture drains serving a single lavatory must be a minimum of 11/4 inches in diameter.
(2) Fixture drains serving two or three fixtures must be a minimum of 11/2 inches in diameter.
(3) Fixture drains serving four or more fixtures that are individually vented must be a minimum of 2 inches in diameter.
(4) Fixture drains for water closets must be a minimum of 3 inches in diameter.
(f) Wet-vented drainage system. Plumbing fixture traps may connect into a wet-vented drainage system which shall be designed and installed to accommodate the passage of air and waste in the same pipe.
(1) Horizontal piping. All parts of a wet-vented drainage system, including the connected fixture drains, shall be horizontal except for wet-vented vertical risers which shall terminate with a 11/2 inch minimum diameter continuous vent. Where required by structural design, wet-vented drain piping may be offset vertically when other vented fixture drains or relief vents are connected to the drain piping at or below the vertical offsets.
(2) Size. A wet-vented drain pipe shall be 2 inches minimum diameter and at least one pipe size larger than the largest connected trap or fixture drain. Not more than three fixtures may connect to a 2-inch diameter wet-vented drain system.
(3) Length of trap arm. Fixture traps shall be located within the distance given in § 3280.611(c)(5). Not more than one trap shall connect to a trap arm.
(g) Offsets and branch fittings—(1) Changes in direction. Changes in direction of drainage piping shall be made by the appropriate use of approved or listed fittings, and shall be of the following angles: 111/4, 221/2, 45, 60, or 90 degrees; or other approved or listed fittings or combinations of fittings with equivalent radius or sweep.
(2) Horizontal to vertical. Horizontal drainage lines, connecting with a vertical pipe shall enter through 45-degree “Y” branches, 60-degree “Y” branches, long-turn “TY” branches, sanitary “T” branches, or other approved or listed fittings or combination of fittings having equivalent sweep. Fittings having more than one branch at the same level shall not be used, unless the fitting is constructed so that the discharge from any one branch cannot readily enter any other branch. However, a double sanitary “T” may be used when the drain line is increased not less than two pipe sizes.
(3) Horizontal to horizontal and vertical to horizontal. Horizontal drainage lines connecting with other horizontal drainage lines or vertical drainage lines connected with horizontal drainage lines shall enter through 45-degree “Y” branches, long-turn “TY” branches, or other approved or listed fittings or combination of fittings having equivalent sweep.
(h) Grade of horizontal drainage piping. Except for fixture connections on the inlet side of the trap, horizontal drainage piping shall be run in practical alignment and have a uniform grade of not less than 1/4 inch per foot toward the manufactured home drain outlet. Where it is impractical, due to the structural features or arrangement of any manufactured home, to obtain a grade of 1/4 inch per foot, the pipe or piping may have a grade of not less than 1/8 inch per foot, when a full size cleanout is installed at the upper end.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4586, Feb. 12, 1987; 58 FR 55015, Oct. 25, 1993; 78 FR 73986, Dec. 9, 2013]
§ 3280.611
Vents and venting.
(a) General. Each plumbing fixture trap shall be protected against siphonage and back pressure, and air circulation shall be ensured throughout all parts of the drainage system by means of vents installed in accordance with the requirements of this section and as otherwise required by this standard.
(b) Materials—(1) Pipe. Vent piping must be standard weight galvanized steel, brass, copper tube DWV, listed Scheduled 40 ABS plastic, listed Scheduled 40 PVC plastic, cast iron, or other listed or approved materials.
(2) Fittings. Appropriate fittings shall be used for all changes in direction or size and where pipes are joined. The material and design of vent fittings shall conform to the type of piping used.
(i) Fittings for screw pipe shall be cast iron, malleable iron, plastic, or brass, with standard pipe threads.
(ii) Fittings for copper tubing shall be cast brass or wrought copper.
(iii) Fittings for plastic piping shall be made to approved applicable standards.
(iv) Brass adaptor fittings or wrought copper shall be used to join copper tubing to threaded pipe.
(v) Listed rectangular tubing may be used for vent piping only providing it has an open cross section at least equal to the circular vent pipe required. Listed transition fittings shall be used.
(c) Size of vent piping—(1) Main vent. The drain piping for each toilet shall be vented by a 11/2 inch minimum diameter vent or rectangular vent of venting cross section equivalent to or greater than the venting cross section of a 11/2 inch diameter vent, connected to the toilet drain by one of the following methods:
(i) A 11/2 inch diameter (min.) individual vent pipe or equivalent directly connected to the toilet drain within the distance allowed in § 3280.611(c)(5), for 3-inch trap arms undiminished in size through the roof,
(ii) A 11/2 inch diameter (min.) continuous vent or equivalent, indirectly connected to the toilet drain piping within the distance allowed in § 3280.611(c)(5) for 3 inch trap arms through a 2-inch wet vented drain that carries the waste of not more than one fixture, or,
(iii) Two or more vented drains when at least one is wet-vented, or 2-inch diameter (minimum), and each drain is separately connected to the toilet drain. At least one of the drains shall connect within the distance allowed in § 3280.611(c)(5) for 3-inch trap arms.
(2) Vent pipe areas. Each individually vented fixture with a 11/2 inch or smaller trap shall be provided with a vent pipe equivalent in area to a 11/4 inch nominal pipe size. The main vent, toilet vent and relief vent, and the continuous vent of wet-vented systems shall have an area equivalent to 11/2 inch nominal pipe size.
(3) Common vent. When two fixture traps located within the distance allowed from their vent have their trap arms connected separately at the same level into an approved double fitting, an individual vent pipe may serve as a common vent without any increase in size.
(4) Intersecting vents. Where two or more vent pipes are joined together, no increase in size shall be required; however, the largest vent pipe shall extend full size through the roof.
(5) Distance of fixture trap from vent shall not exceed the values given in the following table:
Maximum Distance of Fixtures From Vent Trap
Size of fixture drain (inches) | Distance trap to vent
11/4 | 4 ft. 6 in.
11/2 | 4 ft 6 in.
2 | 5 ft.
3 | 6 ft.
(d) Mechanical Vents. Where mechanical vents are used as a secondary vent system for plumbing fixtures that are protected by traps, the mechanical vents must comply with paragraphs (d)(1) or (2) of this section.
(1) Spring-operated mechanical (anti-siphon) vents must comply with the following:
(i) No more than two fixtures individually protected by the spring-operated mechanical vent may be drained by a common 11/2 inch diameter drain.
(ii) The drain size for three or more fixtures individually protected by a spring-operated mechanical vent must be at least 2 inches in diameter.
(iii) Spring-operated mechanical vents are restricted to venting fixtures with 11/2 inch traps.
(iv) A spring-operated mechanical vent must be installed in a location that allows a free flow of air and is accessible for inspection, maintenance, and replacement. The sealing function must be at least 6 inches above the top of the trap arm.
(v) Materials for the spring-operated mechanical vents must be as follows:
(A) Cap and housing must be listed acrylonitrile-butadiene-styrene, DWV grade;
(B) Stem must be DWV grade nylon or acetal;
(C) Spring must be stainless steel wire, Type 302; and
(D) Sealing disc must be either:
(1) Neoprene, conforming to CISPI-HSN-85, Specification for Neoprene Rubber Gaskets for HUB and Spigot Cast Iron Soil Pipe and Fittings (incorporated by reference, see § 3280.4), and to ASTM C564-97, Standard Specification for Rubber Gaskets for Cast Iron Soil Pipe and Fittings (incorporated by reference, see § 3280.4); or
(2) Other material, conforming to ASTM C920-02, Standard Specification for Elastomeric Joint Sealants (incorporated by reference, see § 3280.4), and to ASTM D4635-01, Standard Specification for Polyethylene Films Made from Low-Density Polyethylene for General Use and Packaging Applications (incorporated by reference, see § 3280.4).
(2) Gravity-operated mechanical (air admittance valves) vents must comply with the following:
(i) Where installed to vent any fixture, the drain system must have a minimum 11/2 inch diameter vent that terminates outside the manufactured home.
(ii) Where gravity-operated mechanical vent devices terminate in the attic cavity, the following requirements must be met:
(A) The attic cavity must be accessible;
(B) The sealing device must be installed a minimum of 6 inches above the insulation materials; and
(C) The attic must be vented in accordance with § 3280.504(c)(1)(i);
(3) Mechanical vents must be installed in accordance with the vent manufacturer's instructions.
(e) Grade and connections—(1) Horizontal vents. Each vent shall extend vertically from its fixture “T” or point of connection with the waste piping to a point not less than 6 inches above the extreme flood level of the fixture it is venting before offsetting horizontally or being connected with any other vent pipe. Vents for horizontal drains shall connect above the centerline of the drain piping ahead (downstream) of the trap. Where required by structural conditions, vent piping may offset below the rim of the fixture at the maximum angle or height possible.
(f) Vent terminal. Vents must terminate through the roof or wall, or to a mechanical vent device in accordance with paragraph (d) of this section.
(1) Roof extension. Each vent pipe must extend through its flashing and terminate vertically. Vents that extend through the roof must extend undiminished in size, not less than 2 inches above the roof. Vent openings must be at least 3 feet away from any motor-driven air intake that opens into any habitable area.
(2) Wall extensions. Extensions through exterior walls must terminate downward, have a screen to prevent entrance of birds and rodents, and be located as follows:
(i) Extensions must not be located beneath a door, window, or other opening;
(ii) Extensions must be a minimum of 10 feet above the finished floor;
(iii) Extensions must be located a minimum of 2 feet above any building opening that is within 10 feet horizontally of any extension; and
(iv) Extensions must not terminate under an overhang with soffit vents.
(3) Flashing. The opening around each vent pipe shall be made watertight by an adequate flashing or flashing material.
(g) Vent caps. Vent caps, if provided, shall be of the removable type (without removing the flashing from the roof). When vent caps are used for roof space ventilation and the caps are identical to vent caps used for the plumbing system, plumbing system caps shall be identified with permanent markings.
[40 FR 58752, Dec. 18, 1975, as amended at 42 FR 961, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55015, Oct. 25, 1993; 78 FR 73986, Dec. 9, 2013]
§ 3280.612
Tests and inspection.
(a) Water system. All water piping in the water distribution system shall be subjected to a pressure test. The test shall be made by subjecting the system to air or water at 100 psi for 15 minutes without loss of pressure.
(b) Drainage and vent system and plumbing fixtures. The waste and vent system shall be tested by one of the three following alternate methods for evidence or indication of leakage:
(1) Water test. Before plumbing fixtures are connected, all of the openings into the piping shall be plugged and the entire piping system subjected to a static water test for 15 minutes by filling it with water to the top of the highest vent opening. There shall be no evidence of leakage.
(2) Air test. After all fixtures have been installed, the traps filled with water, and the remaining openings securely plugged, the entire system shall be subjected to a 2-inch (manometer) water column air pressure test. If the system loses pressure, leaks may be located with smoke pumped into the system, or with soap suds spread on the exterior of the piping (Bubble test).
(3) Flood level test. The manufactured home shall be in a level position, all fixtures shall be connected, and the entire system shall be filled with water to the rim of the water closet bowl. (Tub and shower drains shall be plugged). After all trapped air has been released, the test shall be sustained for not less than 15 minutes without evidence of leaks. Then the system shall be unplugged and emptied. The waste piping above the level of the water closet bowl shall then be tested and show no indication of leakage when the high fixtures are filled with water and emptied simultaneously to obtain the maximum possible flow in the drain piping.
(c) Fixture test. The plumbing fixtures and connections shall be subjected to a flow test by filling them with water and checking for leaks and retarded flow while they are being emptied.
(d) Shower compartments. Shower compartments and receptors shall be tested for leaks prior to being covered by finish material. Each pan shall be filled with water to the top of the dam for not less than 15 minutes without evidence of leakage.
[40 FR 58752, Dec. 18, 1975, as amended at 42 FR 961, Jan. 4, 1977; 42 FR 54383, Oct. 5, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55015, Oct. 25, 1993]

Subpart H—Heating, Cooling and Fuel Burning Systems
§ 3280.701
Scope.
Subpart H of this standard covers the heating, cooling and fuel burning equipment installed within, on, or external to a manufactured home.
§ 3280.702
Definitions.
The definitions in this subpart apply to subpart H only.
Accessible, when applied to a fixture, connection, appliance or equipment, means having access thereto, but which may require the removal of an access panel, door or similar obstruction.
Air conditioner blower coil system means a comfort cooling appliance where the condenser section is placed external to the manufactured home and evaporator section with circulating blower attached to the manufactured home air supply duct system. Provision must be made for a return air system to the evaporator/blower section. Refrigerant connection between the two parts of the system is accomplished by tubing.
Air conditioner split system means a comfort cooling appliance where the condenser section is placed external to the manufactured home and the evaporator section incorporated into the heating appliance or with a separate blower/coil section within the manufactured home. Refrigerant connection between the two parts of the system is accomplished by tubing.
Air conditioning condenser section means that portion of a refrigerated air cooling or (in the case of a heat pump) heating system which includes the refrigerant pump (compressor) and the external heat exchanger.
Air conditioning evaporator section means a heat exchanger used to cool or (in the case of a heat pump) heat air for use in comfort cooling (or heating) the living space.
Air conditioning self contained system means a comfort cooling appliance combining the condenser section, evaporator and air circulating blower into one unit with connecting ducts for the supply and return air systems.
Air duct means conduits or passageways for conveying air to or from heating, cooling, air conditioning or ventilation equipment, but not including the plenum.
Automatic pump (oil lifter) means a pump, not an integral part of the oil-burning appliance, that automatically pumps oil from the supply tank and delivers the oil under a constant head to an oil-burning appliance.
Btu. British thermal units means the quantity of heat required to raise the temperature of one pound of water one degree Fahrenheit.
Btuh means British thermal units per hour.
Burner means a device for the final conveyance of fuel or a mixture of fuel and air to the combustion zone.
Central air conditioning system means either an air conditioning split system or an external combination heating/cooling system.
Class 0 air ducts and air connectors means air ducts and air connectors having a fire hazard classification of zero when tested in accordance with UL 181-2003, Factory-Made Air Ducts and Air Connectors (incorporated by reference, see § 3280.4).
Class 1 air ducts and air connectors means air ducts and air connectors having a flame spread rating of not over 25 without evidence of continued progressive combustion and a smoke developed rating of not over 50 when tested in accordance with UL 181-2003, Standard for Safety Factory-Made Air Ducts and Air Connectors (incorporated by reference, see § 3280.4).
Clearance means the distance between the appliance, chimney, vent, chimney or vent connector or plenum and the nearest surface.
Combination space heating and water heating appliance means a listed unit that is designed to provide space heating and water heating from a single primary energy source.
Connector-Gas appliance: means a flexible or semi-rigid connector used to convey fuel gas between a gas outlet and a gas appliance.
Direct-vent system means a system or method of construction where all air for combustion is derived directly from the outside atmosphere and all flue gases are discharged to the outside atmosphere.
Direct-vent system appliance means an appliance that is installed with a direct vent system.
External combination heating/cooling system means a comfort conditioning system placed external to the manufactured home with connecting ducts to the manufactured home for the supply and return air systems.
Factory-built fireplace means a hearth, fire chamber and chimney assembly composed of listed factory-built components assembled in accordance with the terms of listing to form a complete fireplace.
Fireplace stove means a chimney connected solid fuel-burning stove having part of its fire chamber open to the room.
Fuel gas piping system means the arrangement of piping, tubing, fittings, connectors, valves and devices designed and intended to supply or control the flow of fuel gas to the appliance(s).
Fuel oil piping system means the arrangement of piping, tubing, fittings, connectors, valves and devices designed and intended to supply or control the flow of fuel oil to the appliance(s).
Gas clothes dryer means a device used to dry wet laundry by means of heat derived from the combustion of fuel gases.
Gas refrigerator means a gas-burning appliance which is designed to extract heat from a suitable chamber.
Gas supply connection means the terminal end or connection to which a gas supply connector is attached.
Gas supply connector, manufactured home means a listed flexible connector designed for connecting the manufactured home to the gas supply source.
Gas vents means factory-built vent piping and vent fittings listed by an approved testing agency, that are assembled and used in accordance with the terms of their listings, for conveying flue gases to the outside atmosphere.
(1) Type B gas vent means a gas vent for venting gas appliances with draft hoods and other gas appliances listed for use with Type B gas vents.
(2) Type BW gas vent means a gas vent for venting listed gas-fired vented wall furnaces.
Heat producing appliance means all heating and cooking appliances and fuel burning appliances.
Heating appliance means an appliance for comfort heating, domestic water heating, or a combination of comfort heating and domestic water heating.
Liquefied petroleum gases. The terms Liquefied petroleum gases, LPG and LP-Gas as used in this standard shall mean and include any material which is composed predominantly of any of the following hydrocarbons, or mixtures of them: propane, propylene butanes (normal butane or isobutane), and butylenes.
Plenum means an air compartment which is part of an air-distributing system, to which one or more ducts or outlets are connected.
(1) Furnace supply plenum is a plenum attached directly to, or an integral part of, the air supply outlet of the furnace.
(2) Furnace return plenum is a plenum attached directly to, or an integral part of, the return inlet of the furnace.
Quick-disconnect device means a hand-operated device which provides a means for connecting and disconnecting a gas supply or connecting gas systems and which is equipped with an automatic means to shut off the gas supply when the device is disconnected.
Readily accessible means direct access without the necessity of removing any panel, door, or similar obstruction.
Roof jack means that portion of a manufactured home heater flue or vent assembly, including the cap, insulating means, flashing, and ceiling plate, located in and above the roof of a manufactured home.
Sealed combustion system appliance means an appliance which by its inherent design is constructed so that all air supplied for combustion, the combustion system of the appliance, and all products of combustion are completely isolated from the atmosphere of the space in which it is installed.
Water heater means an appliance for heating water for domestic purposes.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4586, Feb. 12, 1987; 58 FR 55015, Oct. 25, 1993; 78 FR 73987, Dec. 9, 2013]
§ 3280.703
Minimum standards.
Heating, cooling and fuel burning appliances and systems in manufactured homes shall be free of defects, and shall conform to applicable standards in the following table unless otherwise specified in this standard. (See § 3280.4) When more than one standard is referenced, compliance with any one such standard shall meet the requirements of this standard.

Appliances
Heating and Cooling Equipment, Second Edition, with 1999 revisions—UL 1995, 1995.
Liquid Fuel-Burning Heating Appliances for Manufactured Homes and Recreational Vehicles, Seventh Edition, with 1997 revisions—UL 307A-1995.
Fixed and Location-Dedicated Electric Room Heaters, Second Edition, with 1998 revisions—UL 2021-1997.
Electric Baseboard Heating Equipment, Fourth Edition, with 1998 revisions—UL 1042-1994.
Electric Central Air Heating Equipment—UL 1096-Fourth Edition-1986 with revisions July 16, 1986, and January 30, 1988.
Gas Burning Heating Appliances for Manufactured Homes and Recreational Vehicles, Fourth Edition, with 1998 revisions—UL 307B-1995.
Gas Clothes Dryers Volume 1, Type 1 Clothes Dryers—ANSI Z21.5.1-/CSA 7.1-M99—1999 with Addendum Z21.5.1a-1999.
Gas Fired Absorption Summer Air Conditioning Appliances—ANSI Z21.40.1/CGA 2.91-M961996.
Gas-Fired Central Furnaces (Except Direct Vent System Central Furnaces)—ANSI Z21.47-1990 with Addendum Z21.47a-1990 and Z21.47b-1992.
Decorative Gas Appliances for Installation in Solid Fuel Burning Fireplaces—RADCO DS-010-91 (incorporated by reference, see § 3280.4).
Household Cooking Gas Appliances—ANSI Z21.1-2000.
Refrigerators Using Gas Fuel—ANSI Z21.19-1990, with Addendum ANSI Z21.19a-1992 and Z21.19b-1995.
Gas Water Heaters—Volume 1, Storage Water Heaters with Input Ratings of 75,000 BTU per hour or Less—ANSI Z21.10.1-1998 with Addendum Z21.10.1a-2000.
Household Electric Storage Tank Water Heaters, Tenth Edition—UL 174-1996, with 1997 revisions.

Ferrous Pipe and Fittings
Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless—ASTM A53-93.
Standard Specification for Electric-Resistance-Welded Coiled Steel Tubing for Gas and Fuel Oil Lines—ASTM A539-1999.
Pipe Threads, General Purpose (Inch)—ANSI/ASME B1.20.1-1983.
Welding and Seamless Wrought Steel Pipe—ANSI/ASME B36.10-1979.

Nonferrous Pipe, Tubing, and Fittings
Standard Specification for Seamless Copper Water Tube—ASTM B88-93.
Standard Specification for Seamless Copper Tube for Air Conditioning and Refrigeration Field Service—ASTM B280-95a.
Connectors for Gas Appliances—ANSI Z21.24/CGA 6.10-M97-1997.
Manually Operated Gas Valves for Appliances, Appliance Connector Valves and Hose End Valves—ANSI Z21.15/CGA 9.1-M97-1997.
Standard for Gas Supply Connectors for Manufactured Homes—IAPMO TSC 9-1997.
Standard Specification for General Requirements for Wrought Seamless Copper and Copper-Alloy Tubes—ASTM B251-93.
Standard Specification for Seamless Copper Pipe, Standard Sizes—ASTM B42-93.

Miscellaneous
Factory-Made Air Ducts and Air Connectors, UL 181, Ninth Edition, April 4, 1996, with revisions through May 15, 2003 (incorporated by reference, see § 3280.4).
Standard for Safety Closure Systems for use with Rigid Air Ducts and Air Connectors, UL 181A, 1994, with 1998 revisions.
Standard for Safety Closure Systems for use with Flexible Air Ducts and Air Connectors, First Edition—UL 181B, 1995, with 1998 revisions.
Tube Fittings for Flammable and Combustible Fluids, Refrigeration Service, and Marine Use, Sixth Edition—UL 109-1997, with 2001 revisions.
Pigtails and Flexible Hose Connectors for LP-Gas, Seventh Edition—UL 569, 1995 with 2001 revisions.
Roof Jacks for Manufactured Homes and Recreational Vehicles, Eighth Edition—UL 311, 1994, with 1998 revisions.
Relief Valves for Hot Water Supply Systems, ANSI Z21.22-1999, (incorporated by reference, see § 3280.4).
Automatic Gas Ignition Systems and Components—ANSI Z21.20 with Addendum Z21.20a-2000.
Automatic Valves for Gas Appliances—ANSI Z21.21/CSA 6.5-2000.
Gas Appliance Thermostats—ANSI Z21.23-93 (incorporated by reference, see § 3280.4).
Gas Vents, Ninth Edition—UL 441, 1996 with 1999 revisions.
Standard for the Installation of Oil-Burning Equipment, NFPA 31-01 (incorporated by reference, see § 3280.4).
National Fuel Gas Code—NFPA 54-2002/ANSI Z223.1-2002.
Warm Air Heating and Air Conditioning Systems, NFPA 90B, 1996 Edition.
Liquefied Petroleum Gas Code, NFPA 58-2001 Edition.
Flares for Tubing—SAE-J533b-1992.
Factory-Built Chimneys for Residential Type and Building Heating Appliances, Ninth Edition—UL 103, 1995, with 1999 revisions.
Factory-Built Fireplaces, Seventh Edition—UL 127-1996, with 1999 revisions.
Solid-Fuel Type Room Heaters, Fifth Edition—UL 1482, 1995, with 2000 revisions.
Fireplace Stoves, Eight Edition, with 2000 revisions—UL 737, 1996.
Unitary Air-Conditioning and Air-Source Heat Pump Equipment—ANSI/ARI 210/240-89.
AGA Requirements for Gas Connectors for Connection of Fixed Appliances for Outdoor Installation, Park Trailers, and Manufactured (Mobile) Homes to the Gas Supply—No. 3-87.
[58 FR 55015, Oct. 25, 1993, as amended at 70 FR 72046, Nov. 30, 2005; 78 FR 73987, Dec. 9, 2013]
§ 3280.704
[Reserved]
§ 3280.705
Gas piping systems.
(a) General. The requirements of this section shall govern the installation of all fuel gas piping attached to any manufactured home. The gas piping supply system shall be designed for a pressure not exceeding 14 inch water column (1/2 psi) and not less than 7 inch water column (1/4 psi). The manufacturer shall indicate in his written installation instructions the design pressure limitations for safe and effective operation of the gas piping system. None of the requirements listed in this section shall apply to the piping supplied as a part of an appliance. All exterior openings around piping, ducts, plenums or vents shall be sealed to resist the entrance of rodents.
(b) Materials. All materials used for the installation, extension, alteration, or repair of any gas piping system shall be new and free from defects or internal obstructions. It shall not be permissible to repair defects in gas piping or fittings. Inferior or defective materials shall be removed and replaced with acceptable material. The system shall be made of materials having a melting point of not less than 1,450 F, except as provided in § 3280.705(e). They shall consist of one or more of the materials described in § 3280.705(b) (1) through (4).
(1) Steel or wrought-iron pipe shall comply with ANSI Standard B36.10-1979, Welded and Seamless Wrought Steel Pipe. Threaded brass pipe in iron pipe sizes may be used. Threaded brass pipe shall comply with ASTM B43-91, Standard Specification for Seamless Red Brass Pipe, Standard Sizes.
(2) Fittings for gas piping shall be wrought iron, malleable iron, steel, or brass (containing not more than 75 percent copper).
(3) Copper tubing must be annealed type, Grade K or L, conforming to the Standard Specification for Seamless Copper Water Tube, ASTM B88-93, or must comply with the Standard Specification for Seamless Copper Tube for Air Conditioning and Refrigeration Service, ASTM B280-1995. Copper tubing must be internally tinned.
(4) Steel tubing must have a minimum wall thickness of 0.032 inch for tubing of 1/2 inch diameter and smaller and 0.049 inch for diameters 1/2 inch and larger. Steel tubing must be in accordance with ASTM Standard Specification for Electric-Resistance-Welded Coiled Steel Tubing for Gas and Fuel Oil Lines, ASTM A539-1999, and must be externally corrosion protected.
(5) Corrugated stainless steel tubing (CSST) systems must be listed and installed in accordance with ANSI/IAS LC-1-1997, Fuel Gas Piping Systems Using Corrugated Stainless Steel Tubing (CSST) (incorporated by reference, see § 3280.4), and the requirements of this section.
(c) Piping design. Each manufactured home requiring fuel gas for any purpose shall be equipped with a natural gas piping system acceptable for LP-gas. Where fuel gas piping is to be installed in more than one section of an expandable or multiple unit home, the design and construction of the crossover(s) shall be as follows:
(1) All points of crossover shall be readily accessible from the exterior of the home.
(2) The connection(s) between units must be made with a connector(s) listed for exterior use or direct plumbing sized in accordance with § 3280.705(d). A shutoff valve of the non-displaceable rotor type conforming to ANSI Z21.15-1997, Manually Operated Gas Valves for Appliances, Appliances Connector Valves, and Hose End Valves, suitable for outdoor use must be installed at each crossover point upstream of the connection.
(3) The connection(s) may be made by a listed quick disconnect device which shall be designed to provide a positive seal of the supply side of the gas system when such device is separated.
(4) The flexible connector, direct plumbing pipe, or “quick disconnect” device shall be provided with protection from mechanical and impact damage and located to minimize the possibility of tampering.
(5) For gas line cross over connections made with either hard pipe or flexible connectors, the crossover point(s) shall be capped on the supply side to provide a positive seal and covered on the other side with a suitable protective covering.
(6) Suitable protective coverings for the connection device(s) when separated, shall be permanently attached to the device or flexible connector.
(7) When a quick disconnect device is installed, a 3 inch by 13/4 inch minimum size tag made of etched, metal-stamped or embossed brass, stainless steel, anodized or alcalde aluminum not less than 0.020 inch thick or other approved material (e.g., 0.005 inch plastic laminates) shall be permanently attached on the exterior wall adjacent to the access to the “quick disconnect” device. Each tag shall be legibly inscribed with the following information using letters no smaller than 1/4 inch high:

Do Not Use Tools To Separate the “Quick-Disconnect” Device
(d) Gas pipe sizing. Gas piping systems shall be sized so that the pressure drop to any appliance inlet connection from any gas supply connection, when all appliances are in operation at maximum capacity, is not more than 0.5 inch water column as determined on the basis of test, or in accordance with table 3280.705(d). When determining gas pipe sizing in the table, gas shall be assumed to have a specific gravity of 0.65 and rated at 1000 B.T.U. per cubic foot. The natural gas supply connection(s) shall be not less than the size of the gas piping but shall be not smaller than 3/4 inch nominal pipe size.
Table to paragraph (d)—Maximum Capacity of Different Sizes of Pipe and Tubing in Thousands of Btu/hr of Natural Gas for Gas Pressures of 0.5 psig or Less, and a Maximum Pressure Drop of 1/2 in. Water Column
ID (in.) | 10 ft | 20 ft | 30 ft | 40 ft | 50 ft | 60 ft | 70 ft | 80 ft | 90 ft | 100 ft
Iron Pipe Sizes—Length
1/4 | 43 | 29 | 24 | 20 | 18 | 16 | 15 | 14 | 13 | 12
3/8 | 95 | 65 | 52 | 45 | 40 | 36 | 33 | 31 | 29 | 27
1/2 | 175 | 120 | 97 | 82 | 73 | 66 | 61 | 57 | 53 | 50
3/4 | 360 | 250 | 200 | 170 | 151 | 138 | 125 | 118 | 110 | 103
1 | 680 | 465 | 375 | 320 | 285 | 260 | 240 | 220 | 215 | 195
EHD ^2 | ID (in.) | 10 ft | 20 ft | 30 ft | 40 ft | 50 ft | 60 ft | 70 ft | 80 ft | 90 ft | 100 ft
Corrugated Stainless Steel Tubing—Length ^1
13 | 3/8 | 31 | 21 | 17 | 14 | 13 | 12 | 11 | 10 | 10 | 9
15 | 3/8 | 42 | 30 | 24 | 20 | 18 | 16 | 15 | 14 | 13 | 12
18 | 1/2 | 79 | 56 | 45 | 39 | 36 | 33 | 30 | 28 | 27 | 25
19 | 1/2 | 91 | 64 | 52 | 45 | 40 | 36 | 35 | 32 | 31 | 29
23 | 3/4 | 155 | 111 | 92 | 80 | 72 | 65 | 60 | 58 | 55 | 52
25 | 3/4 | 184 | 132 | 108 | 93 | 84 | 77 | 71 | 66 | 62 | 60
30 | 1 | 317 | 222 | 180 | 156 | 138 | 126 | 116 | 108 | 103 | 97
31 | 1 | 368 | 258 | 209 | 180 | 161 | 147 | 135 | 127 | 120 | 113
37 | 11/4 | 598 | 426 | 350 | 304 | 273 | 250 | 231 | 217 | 205 | 195
OD (in.) | 10 ft | 20 ft | 30 ft | 40 ft | 50 ft | 60 ft | 70 ft | 80 ft | 90 ft | 100 ft
Copper Tubing—Length
1/4 | 27 | 18 | 15 | 13 | 11 | 10 | 9 | 9 | 8 | 8
3/8 | 56 | 38 | 31 | 26 | 23 | 21 | 19 | 18 | 17 | 16
1/2 | 113 | 78 | 62 | 53 | 47 | 43 | 39 | 37 | 34 | 33
3/4 | 197 | 136 | 109 | 93 | 83 | 75 | 69 | 64 | 60 | 57
1 | 280 | 193 | 155 | 132 | 117 | 106 | 98 | 91 | 85 | 81
^1 Includes losses for four 90-degree bends and two end fittings. Tubing runs with larger numbers of bend and/or fittings shall be increased by an equivalent length of tubing according to the following equation: L = 1.3 n, where L is actual length (ft) of tubing and n is the number of additional fittings and/or bends.
^2 EHD (Equivalent Hydraulic Diameter)—A measure of the hydraulic efficiency between different tubing sizes.
(e) Joints for gas pipe. All pipe joints in the piping system, unless welded or brazed, shall be threaded joints that comply with Pipe Threads, General Purpose (Inch), adopted 25 October 1984, ANSI/ASME B1.20.1-1983. Right and left nipples or couplings shall not be used. Unions, if used, shall be of ground joint type. The material used for welding or brazing pipe connections shall have a melting temperature in excess of 1,000 F.
(f) Joints for tubing. (1) Tubing joints shall be made with either a single or a double flare of 45 degrees in accordance with Flares For Tubing, SAE-J533b-1992 or with other listed vibration-resistant fittings, or joints may be brazed with material having a melting point exceeding 1,000 °F. Metallic ball sleeve compression-type tubing fittings shall not be used.
(2) Steel tubing joints shall be made with a double-flare in accordance with Flares For Tubing, SAE-J533b-1972.
(g) Pipe joint compound. Screw joints shall be made up tight with listed pipe joint compound, insoluble in liquefied petroleum gas, and shall be applied to the male threads only.
(h) Concealed tubing. (1) Copper tubing must not be run inside walls, floors, partitions, or roofs. Corrugated stainless steel tubing (CSST) may be run inside walls, floors, partitions, and roofs under the following conditions:
(i) The CSST is protected from accidental puncture by a steel strike barrier not less than 0.058 inch thick, or the barrier's equivalent, installed between the tubing and the finished wall and extending 4 inches beyond concealed penetrations of plates, firestops, and wall studs, or specified by the tubing manufacturer's instructions; and
(ii) The CSST is installed in single runs and is not rigidly secured.
(2) Where tubing passes through exterior walls, floors, partitions, or similar construction, the tubing must be protected by the use of weather-resistant grommets that snugly fit both the tubing and the hole through which the tubing passes, or protected as specified in the tubing manufacturer's instructions.
(3) Concealed joints: Piping or tubing joints must not be located in any wall, floor, partition, or similar concealed construction space.
(i) Concealed joints. Piping or tubing joints shall not be located in any floor, wall partition, or similar concealed construction space.
(j) Gas supply connections. When gas appliances are installed, at least one gas supply connection shall be provided on each home. The connection shall not be located beneath an exit door. Where more than one connection is provided, the piping system shall be sized to provide adequate capacity from each supply connection.
(k) Identification of gas supply connections. Each manufactured home shall have permanently affixed to the exterior skin at or near each gas supply connection or the end of the pipe, a tag of 3 inches by 13/4 inches minimum size, made of etched, metal-stamped or embossed brass, stainless steel, anodized or alcalde aluminum not less than 0.020 inch thick, or other approved material (e.g., 0.005 inch plastic laminates), which reads as follows. The connector capacity indicated on this tag shall be equal to or greater than the total Btuh rating of all intended gas appliances.

Combination LP-Gas and Natural Gas System
This gas piping system is designed for use of either liquefied petroleum gas or natural gas.
NOTICE: BEFORE TURNING ON GAS BE CERTAIN APPLIANCES ARE DESIGNED FOR THE GAS CONNECTED AND ARE EQUIPPED WITH CORRECT ORIFICES. SECURELY CAP THIS INLET WHEN NOT CONNECTED FOR USE.
When connecting to lot outlet, use a listed gas supply connector for mobile homes rated at ☐ 100,000 Btuh or more; ☐ 250,000 Btuh or more.
Before turning on gas, make certain all gas connections have been made tight, all appliance valves are turned off, and any unconnected outlets are capped.
After turning on gas, test gas piping and connections to appliances for leakage with soapy water or bubble solution, and light all pilots.
The connector capacity indicated on this tag shall be equal to or greater than the total Btuh rating of all intended gas appliances.
(l) LP-gas supply connectors. (1) A listed LP-Gas flexible connection conforming to UL 569-1995, Pigtails and Flexible Hose Connectors for LP Gas, or equal must be supplied when LP-Gas cylinders(s) and regulator(s) are supplied.
(2) Appliance connections. All gas burning appliances shall be connected to the fuel piping. Materials as provided in § 3280.705(b) or listed appliance connectors shall be used. Listed appliance connectors when used shall not run through walls, floors, ceilings or partitions, except for cabinetry, and shall be 3 feet or less in length or 6 feet or less for cooking appliances. Connectors of aluminum shall not be used outdoors. A manufactured home containing a combination LP-natural-gas- system may be provided with a gas outlet to supply exterior appliances when installed in accordance with the following:
(i) No portion of the completed installation shall project beyond the wall of the manufactured home.
(ii) The outlet must be provided with an approved quick-disconnect device, which must be designed to provide a positive seal on the supply side of the gas system when the appliance is disconnected. A shutoff valve of the non-displaceable rotor type conforming to ANSI Z21.15-1997, Manually Operated Gas Valves, must be installed immediately upstream of the quick-disconnect device. The complete device must be provided as part of the original installation.
(iii) Protective caps or plugs for the “quick-disconnect” device, when disconnected, shall be permanently attached to the manufactured home adjacent to the device.
(iv) A tag shall be permanently attached to the outside of the exterior wall of the manufactured home as close as possible to the gas supply connection. The tag shall indicate the type of gas and the Btuh capacity of the outlet and shall be legibly inscribed as follows:
THIS OUTLET IS DESIGNED FOR USE WITH GAS PORTABLE APPLIANCES WHOSE TOTAL INPUT DO NOT EXCEED ___ BTUH. REPLACE PROTECTIVE COVERING OVER CONNECTOR WHEN NOT IN USE.
(3) Valves. A shutoff valve must be installed in the fuel piping at each appliance inside the manufactured home structure, upstream of the union or connector in addition to any valve on the appliance and so arranged to be accessible to permit servicing of the appliance and removal of its components. The shutoff valve must be located within 6 feet of any cooking appliance and within 3 feet of any other appliance. A shutoff valve may serve more than one appliance if located as required by this paragraph (3). The shutoff valve must be of the non-displaceable rotor type and conform to ANSI Z21.15-1997, Manually Operated Gas Valves.
(4) Gas piping system openings. All openings in the gas piping system shall be closed gas-tight with threaded pipe plugs or pipe caps.
(5) Electrical ground. Gas piping shall not be used for an electrical ground.
(6) Couplings. Pipe couplings and unions shall be used to join sections of threaded piping. Right and left nipples or couplings shall not be used.
(7) Hangers and supports. All gas piping shall be adequately supported by galvanized or equivalently protected metal straps or hangers at intervals of not more than 4 feet, except where adequate support and protection is provided by structural members. Solid-iron-pipe gas supply connection(s) shall be rigidly anchored to a structural member within 6 inches of the supply connection(s).
(8) Testing for leakage. (i) Before appliances are connected, piping systems shall stand a pressure of at least six inches mercury or three PSI gage for a period of not less than ten minutes without showing any drop in pressure. Pressure shall be measured with a mercury manometer or slope gage calibrated so as to be read in increments of not greater than one-tenth pound, or an equivalent device. The source of normal operating pressure shall be isolated before the pressure tests are made. Before a test is begun, the temperature of the ambient air and of the piping shall be approximately the same, and constant air temperature be maintained throughout the test.
(ii) After appliances are connected, the piping system shall be pressurized to not less than 10 inches nor more than 14 inches water column and the appliance connections tested for leakage with soapy water or bubble solution.
[40 FR 58752, Dec. 18, 1975, as amended at 42 FR 54383, Oct. 5, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4587, Feb. 12, 1987; 58 FR 55016, Oct. 25, 1993; 70 FR 72050, Nov. 30, 2005; 78 FR 73987, Dec. 9, 2013]
§ 3280.706
Oil piping systems.
(a) General. The requirements of this section shall govern the installation of all liquid fuel piping attached to any manufactured home. None of the requirements listed in this section shall apply to the piping in the appliance(s).
(b) Materials. All materials used for the installation extension, alteration, or repair, of any oil piping systems shall be new and free from defects or internal obstructions. The system shall be made of materials having a melting point of not less than 1,450 F, except as provided in § 280.706(d) and (e). They shall consist of one or more of the materials described in § 3280.706(b) (1) through (4).
(1) Steel or wrought-iron pipe shall comply with ANSI B 36.10-1979, Welded and Seamless Wrought Steel Pipe. Threaded copper or brass pipe in iron pipe sizes may be used.
(2) Fittings for oil piping shall be wrought-iron, malleable iron, steel, or brass (containing not more than 75 percent copper).
(3) Copper tubing must be annealed type, Grade K or L conforming to the Standard Specification for Seamless Copper Water Tube, ASTM B88-93, or shall comply with ASTM B280-1995, Standard Specification for Seamless Copper Tube for Air Conditioning and Refrigeration Field Service.
(4) Steel tubing shall have a minimum wall thickness of 0.032 inch for diameters up to 1/2 inch and 0.049 inch for diameters 1/2 inch and larger. Steel tubing shall be constructed in accordance with the Specification for Electric-Resistance-Welded Coiled Steel Tubing for Gas and Field Oil Lines, ASTM, A539-90a, and shall be externally corrosion protected.
(c) Size of oil piping. The minimum size of all fuel oil tank piping connecting outside tanks to the appliance shall be no smaller than 3/8 inch OD copper tubing or 1/4 inch IPS. If No. 1 fuel oil is used with a listed automatic pump (fuel lifter), copper tubing shall be sized as specified by the pump manufacturer.
(d) Joints for oil piping. All pipe joints in the piping system, unless welded or brazed, shall be threaded joints which comply with ANSI/ASME B1.20.1-1983, Pipe Threads, General Purpose (Inch). The material used for brazing pipe connections shall have a melting temperature in excess of 1,000 F.
(e) Joints for tubing. Joints in tubing shall be made with either a single or double flare of the proper degree, as recommended by the tubing manufacturer, by means of listed tubing fittings, or brazed with materials having a melting point in excess of 1,000 F.
(f) Pipe joint compound. Threaded joints shall be made up tight with listed pipe joint compound which shall be applied to the male threads only.
(g) Couplings. Pipe couplings and unions shall be used to join sections of threaded pipe. Right and left nipples or couplings shall not be used.
(h) Grade of piping. Fuel oil piping installed in conjunction with gravity feed systems to oil heating equipment shall slope in a gradual rise upward from a central location to both the oil tank and the appliance in order to eliminate air locks.
(i) Strap hangers. All oil piping shall be adequately supported by galvanized or equivalently protected metal straps or hangers at intervals of not more than 4 feet, except where adequate support and protection is provided by structural members. Solid-iron-pipe oil supply connection(s) shall be rigidly anchored to a structural member within 6 inches of the supply connection(s).
(j) Testing Tag. A tag must be affixed to each oil-fired appliance stating: “Before setting the system in operation, tank installations and piping must be checked for oil leaks with fuel oil of the same grade that will be burned in the appliance. No other material may be used for testing fuel oil tanks and piping. Tanks must be filled to maximum capacity for the final check for oil leakage.”
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4588, Feb. 12, 1987; 58 FR 55017, Oct. 25, 1993; 70 FR 72050, Nov. 30, 2005; 78 FR 73988, Dec. 9, 2013]
§ 3280.707
Heat producing appliances.
(a) Heat-producing appliances and vents, roof jacks and chimneys necessary for their installation in manufactured homes shall be listed or certified by a nationally recognized testing agency for use in manufactured homes.
(1) A manufactured home shall be provided with a comfort heating system.
(i) When a manufactured home is manufactured to contain a heating appliance, the heating appliance shall be installed by the manufacturer of the manufactured home in compliance with applicable sections of this subpart.
(ii) When a manufactured home is manufactured for field application of an external heating or combination heating/cooling appliance, preparation of the manufactured home for this external application shall comply with the applicable sections of this part.
(2) Each gas and oil burning comfort heating appliance must have an Annual Fuel Utilization Efficiency of not less than that specified in 10 CFR part 430, Energy Conservation Program for Consumer Products: Test Procedures for Furnaces/Boilers, Vented Home Heating Equipment and Pool Heaters.
(b) Fuel-burning heat-producing appliances and refrigeration appliances, except ranges and ovens, shall be of the vented type and vented to the outside.
(c) Fuel-burning appliances shall not be converted from one fuel to another fuel unless converted in accordance with the terms of their listing and the appliance manufacturer's instructions.
(d) Performance efficiency. Each automatic storage water heater must comply with the efficiency requirements of 10 CFR part 430, Energy Conservation Program for Consumer Products: Energy Conservation Standards for Water Heaters.
(1) All automatic electric storage water heaters installed in manufactured homes shall have a standby loss not exceeding 43 watts/meter^2 (4 watts/ft^2) of tank surface area. The method of test for standby loss shall be as described in section 4.3.1 of Household Automatic Electric Storage Type Water Heaters, ANSI C72.1-1972.
(2) All gas and oil-fired automatic storage water heaters shall have a recovery efficiency, E, and a standby loss, S, as described below. The method of test of E and S shall be as described in section 2.7 of Gas Water heaters, Vol. I, Storage Water Heaters with Input/Ratings of 75,000 BTU per hour or less, ANSI Z21.10.1-1998 with addendums Z21.10.1a-2000, and Z21.10.1b-1992, except that for oil-fired units. CF = 1.0, Q = total gallons of oil consumed and H = total heating value of oil in BTU/gallon.
Storage capacity in gallons | Recovery efficiency | Standby loss
Less than 25 | At least 75 percent. | Not more than 7.5 percent.
25 up to 35 | 00 | Not more than 7 percent.
35 or more | 00 | Not more than 6 percent.
(e) Each space heating, cooling or combination heating and cooling system shall be provided with at least one readily adjustable automatic control for regulation of living space temperature. The control shall be placed a minimum of 3 feet from the vertical edge of the appliance compartment door. It shall not be located on an exterior wall or on a wall separating the appliance compartment from a habitable room.
(f) Oil-fired heating equipment. All oil-fired heating equipment must conform to Liquid Fuel-burning Heating Appliances for Manufactured Homes and Recreational Vehicles, UL 307A-1995, with 1997 revisions, and be installed in accordance with Standard for the Installation of Oil Burning Equipment, NFPA 31-01 (incorporated by reference, see § 3280.4). Regardless of the requirements of the above-referenced standards, or any other standards referenced in this part, the following are not required:
(1) External switches or remote controls which shut off the burner or the flow of oil to the burner, or
(2) An emergency disconnect switch to interrupt electric power to the equipment under conditions of excessive temperature.
[40 FR 58752, Dec. 17, 1975, as amended at 42 FR 54383, Oct. 5, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 47 FR 49391, Nov. 1, 1982; 52 FR 4588, Feb. 12, 1987; 52 FR 47553, Dec. 15, 1987; 58 FR 55017, Oct. 25, 1993; 70 FR 72050, Nov. 30, 2005; 78 FR 73988, Dec. 9, 2013]
§ 3280.708
Exhaust duct system and provisions for the future installation of a clothes dryer.
(a) Clothes dryers. (1) All gas and electric clothes dryers shall be exhausted to the outside by a moisture-lint exhaust duct and termination fitting. When the clothes dryer is supplied by the manufacturer, the exhaust duct and termination fittings shall be completely installed by the manufacturer. However, if the exhaust duct system is subject to damage during transportation, it need not be completely installed at the factory when:
(i) The exhaust duct system is connected to the clothes dryer, and
(ii) A moisture lint exhaust duct system is roughed in and installation instructions are provided in accordance with paragraph (b)(3) or (c) of this section.
(2) A clothes dryer moisture-lint exhaust duct shall not be connected to any other duct, vent or chimney.
(3) The exhaust duct shall not terminate beneath the manufactured home.
(4) Moisture-lint exhaust ducts shall not be connected with sheet metal screws or other fastening devices which extend into the interior of the duct.
(5) Moisture-lint exhaust duct and termination fittings shall be installed in accordance with the appliance manufacturer's printed instructions.
(b) Provisions for future installation of a gas clothes dryer. A manufactured home may be provided with “stubbed in” equipment at the factory to supply a gas clothes dryer for future installation by the owner provided it complies with the following provisions:
(1) The “stubbed in” gas outlet shall be provided with a shutoff valve, the outlet of which is closed by threaded pipe plug or cap;
(2) The “stubbed in” gas outlet shall be permanently labeled to identify it for use only as the supply connection for a gas clothes dryer;
(3) A moisture lint duct system consisting of a complete access space (hole) through the wall or floor cavity with a cap or cover on the interior and exterior of the cavity secured in such a manner that they can be removed by a common household tool shall be provided. The cap or cover in place shall limit air infiltration and be designed to resist the entry of water or rodents. The manufacturer is not required to provide the moisture-lint exhaust duct or the termination fitting. The manufacturer shall provide written instructions to the owner on how to complete the exhaust duct installation in accordance with provisions of § 3280.708(a)(1) through (5).
(c) Provisions for future installation of electric clothes dryers. When wiring is installed to supply an electric clothes dryer for future installation by the owner, the manufacturer shall:
(1) Provide a roughed in moisture-lint exhaust duct system consisting of a complete access space (hole) through the wall or floor cavity with a cap or cover on the interior and exterior of the cavity which are secured in such a manner that they can be removed by the use of common household tools. The cap or cover in place shall limit air filtration and be designed to resist the entry of water or rodents into the home. The manufacturer is not required to provide the moisture-lint exhaust duct or the termination fitting;
(2) Install a receptacle for future connection of the dryer;
(3) Provide written instructions on how to complete the exhaust duct installation in accordance with the provisions of paragraphs (a)(1) through (5) of this section.
[42 FR 54383, Oct. 5, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55018, Oct. 25, 1993]
§ 3280.709
Installation of appliances.
(a) The installation of each appliance shall conform to the terms of its listing and the manufacturer's instructions. The installer shall leave the manufacturer's instructions attached to the appliance. Every appliance shall be secured in place to avoid displacement. For the purpose of servicing and replacement, each appliance shall be both accessible and removable.
(b) Heat-producing appliances shall be so located that no doors, drapes, or other such material can be placed or swing closer to the front of the appliance than the clearances specified on the labeled appliances.
(c) Clearances surrounding heat producing appliances shall not be less than the clearances specified in the terms of their listings.
(1) Prevention of storage. The area surrounding heat producing appliances installed in areas with interior or exterior access shall be framed-in or guarded with noncombustible material such that the distance from the appliance to the framing or guarding material is not greater than three inches unless the appliance is installed in compliance with paragraph (c)(2), of this section. When clearance required by the listing is greater than three inches, the guard or frame shall not be closer to the appliance than the distance provided in the listing.
(2) Clearance spaces surrounding heat producing appliances are not required to be framed-in or guarded when:
(i) A space is designed specifically for a clothes washer or dryer;
(ii) Dimensions surrounding the appliance do not exceed three inches; or
(iii) The manufacturer affixes either to a side of an alcove or compartment containing the appliance, or to the appliance itself, in a clearly visible location, a 3″ × 5″ adhesive backed plastic laminated label or the equivalent which reads as follows:

“Warning”
This compartment is not to be used as a storage area. Storage of combustible materials or containers on or near any appliance in this compartment may create a fire hazard. Do not store such materials or containers in this compartment.
(d) All fuel-burning appliances, except ranges, ovens, illuminating appliances, clothes dryers, solid fuel-burning fireplaces and solid fuel-burning fireplace stoves, shall be installed to provide for the complete separation of the combustion system from the interior atmosphere of the manufactured home. Combustion air inlets and flue gas outlets shall be listed or certified as components of the appliance. The required separation may be obtained by:
(1) The installation of direct vent system (sealed combustion system) appliances, or
(2) The installation of appliances within enclosures so as to separate the appliance combustion system and venting system from the interior atmosphere of the manufactured home. There shall not be any door, removable access panel, or other opening into the enclosure from the inside of the manufactured home. Any opening for ducts, piping, wiring, etc., shall be sealed.
(e) A forced air appliance and its return-air system shall be designed and installed so that negative pressure created by the air-circulating fan cannot affect its or another appliance's combustion air supply or act to mix products of combustion with circulating air.
(1) The air circulating fan of a furnace installed in an enclosure with another fuel-burning appliance shall be operable only when any door or panel covering an opening in the furnace fan compartment or in a return air plenum or duct is in the closed position. This does not apply if both appliances are direct vent system (sealed combustion system) appliances.
(2) If a warm air appliance is installed within an enclosure to conform to § 3280.709(d)(2), each warm-air outlet and each return air inlet shall extend to the exterior of the enclosure. Ducts, if used for that purpose, shall not have any opening within the enclosure and shall terminate at a location exterior to the enclosure.
(3) Cooling coils installed as a portion of, or in connection with, any forced-air furnace shall be installed on the downstream side unless the furnace is specifically otherwise listed.
(4) An air conditioner evaporator section shall not be located in the air discharge duct or plenum of any forced-air furnace unless the manufactured home manufacturer has complied with certification required in § 3280.511.
(5) If a cooling coil is installed with a forced-air furnace, the coil shall be installed in accordance with its listing. When a furnace-coil unit has a limited listing, the installation must be in accordance with that listing.
(6) When an external heating appliance or combination cooling/heating appliance is to be field installed, the home manufacturer shall make provision for proper location of the connections to the supply and return air systems. The manufacturer is not required to provide said appliance(s). The preparation by the manufacturer for connection to the home's supply and return air system shall include all fittings and connection ducts to the main duct and return air system such that the installer is only required to provide:
(i) The appliance;
(ii) Any appliance connections to the home; and
(iii) The connecting duct between the external appliance and the fitting installed on the home by the manufacturer. The above connection preparations by the manufacturer do not apply to supply or return air systems designed only to accept external cooling (i.e., self contained air conditioning systems, etc.)
(7) The installation of a self contained air conditioner comfort cooling appliance shall meet the following requirements:
(i) The installation on a duct common with an installed heating appliance shall require the installation of an automatic damper or other means to prevent the cooled air from passing through the heating appliance unless the heating appliance is certified or listed for such application and the supply system is intended for such an application.
(ii) The installation shall prevent the flow of heated air into the external cooling appliance and its connecting ducts to the manufactured home supply and return air system during the operation of the heating appliance installed in the manufactured home.
(iii) The installation shall prevent simultaneous operation of the heating and cooling appliances.
(f) Vertical clearance above cooking top. Ranges shall have a vertical clearance above the cooking top of not less than 24 inches. (See § 3280.204).
(g) Solid fuel-burning factory-built fireplaces and fireplace stoves listed for use in manufactured homes may be installed in manufactured homes provided they and their installation conform to the following paragraphs. A fireplace or fireplace stove shall not be considered as a heating facility for determining compliance with subpart F.
(1) A solid fuel-burning fireplace or fireplace stove shall be equipped with integral door(s) or shutter(s) designed to close the fireplace or fireplace stove fire chamber opening and shall include complete means for venting through the roof, a combustion air inlet, a hearth extension, and means to securely attach the fireplace or the fireplace stove to the manufactured home structure. The installation shall conform to the following paragraphs (g)(1) (i) to (vii) inclusive:
(i) A listed factory-built chimney designed to be attached directly to the fireplace or fireplace stove shall be used. The listed factory built chimney shall be equipped with and contain as part of its listing a termination device(s) and a spark arrester(s).
(ii) A fireplace or fireplace stove, air intake assembly, hearth extension and the chimney shall be installed in accordance with the terms of their listings and their manufacturer's instructions.
(iii) The combustion air inlet shall conduct the air directly into the fire chamber and shall be designed to prevent material from the hearth dropping onto the area beneath the manufactured home.
(iv) The fireplace or fireplace stove shall not be installed in a sleeping room.
(v) Hearth extension shall be of noncombustible material not less than 3/8-inch thick. The hearth shall extend at least 16 inches in front or and at least 8 inches beyond each side of the fireplace or fireplace stove opening. Furthermore the hearth shall extend over the entire surface beneath a fireplace stove and beneath an elevated or overhanging fireplace.
(vi) The label on each solid fuel-burning fireplace and solid fuel-burning fireplace stove shall include the following wording: For use with solid fuel only.
(vii) The chimney shall extend at least three feet above the part of the roof through which it passes and at least two feet above the highest elevation of any part of the manufactured home within 10 feet of the chimney. Portions of the chimney and termination that exceed an elevation of 131/2 ft. above ground level may be designed to be removed for transporting the manufactured home.
(h) A corrosion resistant water drip collection and drain pan must be installed under each water heater that will allow water leaking from the water heater to drain to the exterior of the manufactured home, or to a drain.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 44 FR 66195, Nov. 19, 1979; 58 FR 55018, Oct. 25, 1993; 70 FR 72050, Nov. 30, 2005]
§ 3280.710
Venting, ventilation and combustion air.
(a) The venting as required by § 3280.707(b) shall be accomplished by one or more of the methods given in (a)(1) and (2) of this section:
(1) An integral vent system listed or certified as part of the appliance.
(2) A venting system consisting entirely of listed components, including roof jack, installed in accordance with the terms of the appliance listing and the appliance manufacturer's instructions.
(b) Venting and combustion air systems shall be installed in accordance with the following:
(1) Components shall be securely assembled and properly aligned at the factory in accordance with the appliance manufacturer's instructions except vertical or horizontal sections of a fuel fired heating appliance venting system that extend beyond the roof line or outside the wall line may be installed at the site. Sectional venting systems shall be listed for such applications and installed in accordance with the terms of their listings and manufacturers' instructions. In cases where sections of the venting system are removed for transportation, a label shall be permanently attached to the appliance indicating the following:
Sections of the venting system have not been installed. Warning-do not operate the appliance until all sections have been assembled and installed in accordance with the manufacturer's instructions.
(2) Draft hood connectors shall be firmly attached to draft hood outlets or flue collars by sheet metal screws or by equivalent effective mechanical fasteners.
(3) Every joint of a vent, vent connector, exhaust duct and combustion air intake shall be secure and in alignment.
(c) Venting systems shall not terminate underneath a manufactured home.
(d) Venting system terminations shall be not less than three feet from any motor-driven air intake discharging into habitable areas.
(e) The area in which cooking appliances are located shall be ventilated by a metal duct which may be single wall, not less than 12.5 square inches in cross-sectional area (minimum dimension shall be two inches) located above the appliance(s) and terminating outside the manufactured home, or by listed mechanical ventilating equipment discharging outside the home, that is installed in accordance with the terms of listing and the manufacturer's instructions. Gravity or mechanical ventilation shall be installed within a horizontal distance of not more than ten feet from the vertical front of the appliance(s).
(f) Mechanical ventilation which exhausts directly to the outside atmosphere from the living space of a home shall be equipped with an automatic or manual damper. Operating controls shall be provided such that mechanical ventilation can be separately operated without directly energizing other energy consuming devices.
[49 FR 32012, Aug. 9, 1984, as amended at 58 FR 55018, Oct. 25, 1993]
§ 3280.711
Instructions.
Operating instructions must be provided with each appliance. The operating and installation instructions for each appliance must be provided with the homeowner's manual.
[78 FR 73989, Dec. 9, 2013]
§ 3280.712
Marking.
(a) Information on clearances, input rating, lighting and shutdown shall be attached to the appliances with the same permanence as the nameplate, and so located that it is easily readable when the appliance is properly installed or shutdown for transporting of manufactured home.
(b) Each fuel-burning appliance shall bear permanent marking designating the type(s) of fuel for which it is listed.
§ 3280.713
Accessibility.
Every appliance shall be accessible for inspection, service, repair, and replacement without removing permanent construction. For those purposes, inlet piping supplying the appliance shall not be considered permanent construction. Sufficient room shall be available to enable the operator to observe the burner, control, and ignition means while starting the appliance.
[58 FR 55018, Oct. 25, 1993]
§ 3280.714
Appliances, cooling.
(a) Every air conditioning unit or a combination air conditioning and heating unit shall be listed or certified by a nationally recognized testing agency for the application for which the unit is intended and installed in accordance with the terms of its listing.
(1) Mechanical air conditioners shall be rated in accordance with the ARI Standard 210/240-89 Unitary Air Conditioning and Air Source Unitary Heat Pump Equipment (incorporated by reference, see § 3280.4) and certified by ARI or other nationally recognized testing agency capable of providing follow-up service.
(i) Electric motor-driven unitary air-cooled air conditioners and heat pumps in the cooling mode with rated capacity less than 65,000 BTU/hour (19,045 watts), when rated at ARI standard rating conditions in ARI Standard 210/240-89, Unitary Air-Conditioning and Air-Source Heat Pump Equipment, must have seasonal energy efficiency (SEER) values not less than as specified in 10 CFR Part 430, Energy Conservation Program for Consumer Products: Central Air Conditioners and Heat Pumps Energy Conservation Standards.
(ii) Heat pumps must be certified to comply with all requirements of the ARI Standard 210/240-89, Unitary Air Conditioning and Air-Source Heat Pump Equipment. Electric motor-driven vapor compression heat pumps with supplemental electrical resistance heat must be sized to provide by compression at least 60 percent of the calculated annual heating requirements for the manufactured home being served. A control must be provided and set to prevent operation of supplemental electrical resistance heat at outdoor temperatures above 40 °F (4 °C), except for defrost conditions. Electric motor-driven vapor compression heat pumps with supplemental electric resistance heat conforming to ARI Standard 210/240-89, Unitary Air-Conditioning and Air-Source Heat Pump Equipment, must have Heating Season Performance Factor (HSPF) efficiencies not less than as specified in the 10 CFR Part 430, Energy Conservation Program for Consumer Products: Central Air Conditioners and Heat Pumps Energy Conservation Standards.
(iii) Electric motor-driven vapor compression heat pumps with supplemental electric resistance heat conforming to ARI Standard 210/240-89 Unitary Air-Conditioning and Air-Source Heat Pump Equipment shall show coefficient of performance ratios not less than shown below:
COP
Temperature degrees fahrenheit | Coefficient of performance
47 | 2.5
17 | 1.7
0 | 1.0
(2) Gas fired absorption air conditioners must be listed or certified in accordance with ANSI Z21.40.1-1996, Gas Fired, Heat Activated, Air Conditioning and Heat Pump Appliances (incorporated by reference, see § 3280.4), and certified by a nationally recognized testing agency capable of providing follow-up service.
(3) Direct refrigerating systems serving any air conditioning or comfort-cooling system installed in a manufactured home shall employ a type of refrigerant that ranks no lower than Group 5 in the Underwriters' Laboratories, Inc. “Classification of Comparative Life Hazard of Various Chemicals.”
(4) When a cooling or heat pump coil and air conditioner blower are installed with a furnace or heating appliance, they shall be tested and listed in combination for heating and safety performance by a nationally recognized testing agency.
(5) Cooling or heat pump indoor coils and outdoor sections shall be certified, listed and rated in combination for capacity and efficiency by a nationally recognized testing agency(ies). Rating procedures shall be based on U.S. Department of Energy test procedures.
(b) Installation and instructions. (1) The installation of each appliance shall conform to the terms of its listing as specified on the appliance and in the manufacturer's instructions. The installer shall include the manufacturer's installation instructions in the manufactured home. Appliances shall be secured in place to avoid displacement and movement from vibration and road shock.
(2) Operating instructions shall be provided with the appliance.
(c) Fuel-burning air conditioners shall also comply with § 280.707.
(d) The appliance rating plate shall be so located that it is easily readable when the appliance is properly installed.
(e) Every installed appliance shall be accessible for inspection, service, repair and replacement without removing permanent construction.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55018, Oct. 25, 1993; 70 FR 72051, Nov. 30, 2005; 78 FR 73989, Dec. 9, 2013]
§ 3280.715
Circulating air systems.
(a) Supply system. (1) Supply air ducts, fittings, and any dampers contained therein must be made of galvanized steel, tin-plated steel, or aluminum, or must be listed as Class 0 or Class 1 air ducts and air connectors in accordance with UL 181-2003, Factory-Made Air Ducts and Air Connectors (incorporated by reference, see § 3280.4). Class 1 air ducts and air connectors must be located at least 3 feet from the furnace bonnet or plenum. Air connectors must not be used for exterior manufactured home duct connection. A duct system integral with the structure must be of durable construction that can be demonstrated to be equally resistant to fire and deterioration as required by this section. Furnace supply plenums must be constructed of metal that extends a minimum of 3 feet from the heat exchanger measured along the centerline of airflow. Ducts constructed from sheet metal must be in accordance with the following table:
Minimum Metal Thickness for Ducts ^1
Duct type | Diameter 14 in. or less | Width over 14 in.
Round | 0.013 | 0.016
Enclosed rectangular | .013 | .016
Exposed rectangular | .016 | .019
^1 When “nominal” thicknesses are specified, 0.003 in. shall be added to these “minimum” metal thicknesses.
(2) Sizing of ducts for heating. (i) Ducts shall be so designed that when a labeled forced-air furnace is installed and operated continuously at its normal heating air circulating rate in the manufactured home, with all registers in the full open position, the static pressure measured in the casing shall not exceed 90% of that shown on the label of the appliance. For upflow furnaces the static pressure shall be taken in the duct plenum. For external heating or combination heating/cooling appliances the static pressure shall be taken at the point used by the agency listing or certifying the appliance.
(ii) When an evaporator-coil specifically designed for the particular furnace is installed between the furnace and the duct plenum, the total static pressure shall be measured downstream of the coil in accordance with the appliance label and shall not exceed 90 percent of that shown on the label of the appliance.
(iii) When any other listed air-cooler coil is installed between the furnace and the duct plenum, the total static pressure shall be measured between the furnace and the coil and it shall not exceed 90 percent of that shown on the label of the furnace.
(iv) The minimum dimension of any branch duct shall be at least 11/2 inches, and of any main duct, 21/2 inches.
(3) Sizing of ducts. (i) The manufactured home manufacturer shall certify the capacity of the air cooling supply duct system for the maximum allowable output of ARI certified central air conditioning systems. The certification shall be at operating static pressure of 0.3 inches of water or greater. (See § 3280.511).
(ii) The refrigerated air cooling supply duct system including registers must be capable of handling at least 300 cfm per 10,000 btuh with a static pressure no greater than 0.3 inches of water when measured at room temperature. In the case of application of external self contained comfort cooling appliances or the cooling mode of combination heating/cooling appliances, either the external ducts between the appliance and the manufactured home supply system shall be considered part of, and shall comply with the requirements for the refrigerated air cooling supply duct system, or the connecting duct between the external appliance and the mobile supply duct system shall be a part of the listed appliance. The minimum dimension of any branch duct shall be at least 11/2 inches, and of any main duct, 21/2 inches.
(4) Airtightness of supply duct systems. A supply duct system shall be considered substantially airtight when the static pressure in the duct system, with all registers sealed and with the furnace air circulator at high speed, is at least 80 percent of the static pressure measured in the furnace casing, with its outlets sealed and the furnace air circulator operating at high speed. For the purpose of this paragraph and § 3280.715(b) pressures shall be measured with a water manometer or equivalent device calibrated to read in increments not greater than 1/10 inch water column.
(5) Expandable or multiple manufactured home connections. (i) An expandable or multiple manufactured home may have ducts of the heating system installed in the various units. The points of connection must be so designed and constructed that when the manufactured home is fully expanded or coupled, the resulting duct joint will conform to the requirements of this part.
(ii) The manufacturer must provide installation instructions for supporting, mechanically fastening, sealing, and insulating each crossover duct. The instructions must indicate that no portion of the crossover duct is to be in contact with the ground, and must describe the means to support the duct without compressing the insulation and restricting airflow.
(6) Air supply ducts shall be insulated with material having an effective thermal resistance (R) of not less than 4.0 unless they are within manufactured home insulation having a minimum effective value of R-4.0 for floors or R-6.0 for ceilings.
(7) Unless installed in a basement, supply and return ducts, fittings, and crossover duct plenums exposed directly to outside air, such as those under-chassis crossover ducts or ducts connecting external heating, cooling, or combination heating/cooling appliances, must be insulated with material having a minimum thermal resistance of R-8 in all Thermal Zones. All such insulating materials must have a continuous vapor barrier retarder having a perm rating of not more than 1 perm. Where ducts are exposed underneath the manufactured home, they must comply with paragraph (a)(5)(ii) of this section, and shall be listed for exterior use.
(b) Return air systems—(1) Return air openings. Provisions shall be made to permit the return of circulating air from all rooms and living spaces, except toilet room(s), to the circulating air supply inlet of the furnace.
(2) Duct material. Return ducts and any diverting dampers contained therein shall be in accordance with the following:
(i) Portions of return ducts directly above the heating surfaces, or closer than 2 feet from the outer jacket or casing of the furnace shall be constructed of metal in accordance with § 3280.715(a)(1) or shall be listed Class 0 or Class 1 air ducts.
(ii) Return ducts, except as required by paragraph (a) of this section, shall be constructed of one-inch (nominal) wood boards (flame spread classification of not more than 200), other suitable material no more flammable than one-inch board or in accordance with § 3280.715(a)(1).
(iii) The interior of combustible ducts shall be lined with noncombustible material at points where there might be danger from incandescent particles dropped through the register or furnace such as directly under floor registers and the bottom return.
(iv) Factory made air ducts used for connecting external heating, cooling or combination heating/cooling appliances to the supply system and return air system of a manufactured home shall be listed by a nationally recognized testing agency. Ducts applied to external heating appliances or combination heating/cooling appliances supply system outlets shall be constructed of metal in accordance with § 3280.715(a)(1) or shall be listed Class 0 or Class 1 air ducts for those portions of the duct closer than 2 feet from the outer casing of the appliance.
(v) Ducts applied to external appliances shall be resistant to deteriorating environmental effects, including but not limited to ultraviolet rays, cold weather, or moisture and shall be resistant to insects and rodents.
(3) Sizing. The cross-sectional areas of the return air duct shall not be less than 2 square inches for each 1,000 Btu per hour input rating of the appliance. Dampers shall not be placed in a combination fresh air intake and return air duct so arranged that the required cross-sectional area will not be reduced at all possible positions of the damper.
(4) Permanent uncloseable openings. Living areas not served by return air ducts or closed off from the return opening of the furnace by doors, sliding partitions, or other means shall be provided with permanent uncloseable openings in the doors or separating partitions to allow circulated air to return to the furnace. Such openings may be grilled or louvered. The net free area of each opening shall be not less than 1 square inch for every 5 square feet of total living area closed off from the furnace by the door or partition serviced by that opening. Undercutting doors connecting the closed-off space may be used as a means of providing return air area. However, in the event that doors are undercut, they shall be undercut a minimum of 2 inches and not more than 21/2 inches, as measured from the top surface of the floor decking to the bottom of the door and no more than one half of the free air area so provided shall be counted as return air area.
(c) Joints and seams. Joints and seams of sheet metal and factory-made flexible ducts, including trunks, branches, risers, crossover ducts, and crossover duct plenums, shall be mechanically secured and made substantially airtight. Slip joints in sheet metal ducts shall have a lap of at least one inch and shall be mechanically fastened. Tapes or caulking compounds shall be permitted to be used for sealing mechanically secure joints. Sealants and tapes shall be applied only to surfaces that are dry and dust-, dirt-, oil-, and grease-free. Tapes and mastic closure systems for use with factory-made rigid fiberglass air ducts and air connectors shall be listed in accordance with UL Standard 181A-1994, with 1998 revisions. Tapes and mastic closure systems used with factory-made flexible air ducts and air connectors shall be listed in accordance with UL Standard 181B-1995, with 1998 revisions.
(d) Supports and protection. Ducts must be securely supported. Nails or other fasteners must not be driven or penetrate through duct walls. Where vertical ducts are installed within closets or rooms, they must be enclosed with materials equivalent to those used in the closet or room construction.
(e) Registers and grilles. Fittings connecting the registers and grilles to the duct system must be constructed of metal or material that complies with the requirements of Class 1 or 2 ducts under UL 181-1996 with 1998 revisions, Factory Made Air Ducts and Connectors. Air supply terminal devices (registers) when installed in kitchen, bedrooms, and bathrooms must be equipped with adjustable closeable dampers. Registers or grilles must be constructed of metal or conform with the following:
(1) Be made of a material classified 94V-0 or 94V-1, when tested as described in UL 94-1996, with 2001 revisions, Test for Flammability of Plastic Materials for Parts in Devices and Appliances, Fifth Edition; and
(2) Floor registers or grilles shall resist without structural failure a 200 lb. concentrated load on a 2-inch diameter disc applied to the most critical area of the exposed face of the register or grille. For this test the register or grille is to be at a temperature of not less than 165 °F and is to be supported in accordance with the manufacturer's instructions.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4589, Feb. 12, 1987; 58 FR 55019, Oct. 25, 1993; 70 FR 72051, Nov. 30, 2005; 78 FR 73989, Dec. 9, 2013]

Subpart I—Electrical Systems
§ 3280.801
Scope.
(a) Subpart I of this part and Part II of Article 550 of the National Electrical Code (NFPA No. 70-2005) cover the electrical conductors and equipment installed within or on manufactured homes and the conductors that connect manufactured homes to a supply of electricity.
(b) In addition to the requirements of this part and Part II of Article 550 of the National Electrical Code (NFPA No. 70-2005), the applicable portions of other Articles of the National Electrical Code must be followed for electrical installations in manufactured homes. The use of arc-fault breakers under Articles 210.12(A) and (B), 440.65, and 550.25(A) and (B) of the National Electrical Code, NFPA No. 70-2005 is not required. However, if arc-fault breakers are provided, such use must be in accordance with the National Electrical Code, NFPA No. 70-2005. Wherever the requirements of this standard differ from the National Electrical Code, these standards apply.
(c) The provisions of this standard apply to manufactured homes intended for connection to a wiring system nominally rated 120/240 volts, 3-wire AC, with grounded neutral.
(d) All electrical materials, devices, appliances, fittings and other equipment shall be listed or labeled by a nationally recognized testing agency and shall be connected in an approved manner when in service.
(e) Aluminum conductors, aluminum alloy conductors, and aluminum core conductors such as copper clad aluminum; are not acceptable for use in branch circuit wiring in manufactured homes.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55019, Oct. 25, 1993; 70 FR 72051, Nov. 30, 2005; 71 FR 19639, Apr. 17, 2006]
§ 3280.802
Definitions.
(a) The following definitions are applicable to subpart I only.
(1) Accessible (i) (As applied to equipment) means admitting close approach because not guarded by locked doors, elevation, or other effective means. (See readily accessible.)
(ii) (As applied to wiring methods) means capable of being removed or exposed without damaging the manufactured home structure or finish, or not permanently closed-in by the structure or finish of the manufactured home (see concealed and exposed).
(2) Air conditioning or comfort cooling equipment means all of that equipment intended or installed for the purpose of processing the treatment of air so as to control simultaneously its temperature, humidity, cleanliness, and distribution to meet the requirements of the conditioned space.
(3)(i) Appliance means utilization equipment, generally other than industrial, normally built in standardized sizes or types, which is installed or connected as a unit to perform one or more functions, such as clothes washing, air conditioning, food mixing, deep frying, etc.
(ii) Appliance, fixed means an appliance which is fastened or otherwise secured at a specific location.
(iii) Appliance, portable means an appliance which is actually moved or can easily be moved from one place to another in normal use. For the purpose of this Standard, the following major appliances are considered portable if cord-connected: refrigerators, clothes washers, dishwashers without booster heaters, or other similar appliances.
(iv) Appliance, stationary means an appliance which is not easily moved from one place to another in normal use.
(4) Attachment plug (plug cap) (cap) means a device which, by insertion in a receptacle, establishes connection between the conductors of the attached flexible cord and the conductors connected permanently to the receptacle.
(5) Bonding means the permanent joining of metallic parts to form an electrically conductive path which will assure electrical continuity and the capacity to conduct safely any current likely to be imposed.
(6) Branch circuit (i) means the circuit conductors between the final overcurrent device protecting the circuit and the outlet(s). A device not approved for branch circuit protection, such as a thermal cutout or motor overload protective device, is not considered as the overcurrent device protecting the circuit.
(ii) Branch circuit—appliance means a branch circuit supplying energy to one or more outlets to which appliances are to be connected, such circuits to have no permanently connected lighting fixtures not a part of an appliance.
(iii) Branch circuit—general purpose means a circuit that supplies a number of outlets for lighting and appliances.
(iv) Branch circuit—individual means a branch circuit that supplies only one utilization equipment.
(7) Cabinet means an enclosure designed either for surface or flush mounting, and provided with a frame, mat, or trim in which swinging doors are hung.
(8) Circuit breaker means a device designed to open and close a circuit by nonautomatic means, and to open the circuit automatically on a predetermined overload of current without injury to itself when properly applied within its rating.
(9) Concealed means rendered inaccessible by the structure or finish of the manufactured home. Wires in concealed raceways are considered concealed, even though they may become accessible by withdrawing them. (See accessible (As applied to wiring methods))
(10) Connector, pressure (solderless) means a device that establishes a connection between two or more conductors or between one or more conductors and a terminal by means of mechanical pressure and without the use of solder.
(11) Dead front (as applied to switches, circuit-breakers, switchboards, and distribution panelboard) means so designed, constructed, and installed that no current-carrying parts are normally exposed on the front.
(12) Demand factor means the ratio of the maximum demand of a system, or part of a system, to the total connected load of a system or the part of the system under consideration.
(13) Device means a unit of an electrical system that is intended to carry but not utilize electrical energy.
(14) Disconnecting means means a device, or group of devices, or other means by which the conductors of a circuit can be disconnected from their source of supply.
(15) Distribution panelboard means a single panel or a group of panel units designed for assembly in the form of a single panel, including buses, and with or without switches or automatic overcurrent protective devices or both, for the control of light, heat, or power circuits of small individual as well as aggregate capacity; designed to be placed in a cabinet placed in or against a wall or partition and accessible only from the front.
(16) Enclosed means surrounded by a case that will prevent a person from accidentally contacting live parts.
(17) Equipment means a general term, including material, fittings, devices, appliances, fixtures, apparatus, and the like used as a part of, or in connection with, an electrical installation.
(18) Exposed (i) (As applied to live parts) means capable of being inadvertently touched or approached nearer than a safe distance by a person. It is applied to parts not suitably guarded, isolated, or insulated. (See accessible and concealed.)
(ii) (As applied to wiring method) means on or attached to the surface or behind panels designed to allow access. (See Accessible (as applied to wiring methods))
(19) Externally operable means capable of being operated without exposing the operator to contact with live parts.
(20) Feeder assembly means the overhead or under-chassis feeder conductors, including the grounding conductor, together with the necessary fittings and equipment, or a power supply cord approved for manufactured home use, designed for the purpose of delivering energy from the source of electrical supply to the distribution panelboard within the manufactured home.
(21) Fitting means an accessory, such as a locknut, bushing, or other part of a wiring system, that is intended primarily to perform a mechanical rather than an electrical function.
(22) Ground means a conducting connection, whether intentional or accidental, between an electrical circuit or equipment and earth, or to some conducting body that serves in place of the earth.
(23) Grounded means connected to earth or to some conducting body that serves in place of the earth.
(24) Grounded conductor means a system or circuit conductor that is intentionally grounded.
(25) Grounding conductor means a conductor used to connect equipment or the grounded circuit of a wiring system to a grounding electrode or electrodes.
(26) Guarded means covered, shielded, fenced, enclosed, or otherwise protected by means of suitable covers, casings, barriers, rails, screens, mats or platforms to remove the likelihood of approach or contact by persons or objects to a point of danger.
(27) Isolated means not readily accessible to persons unless special means for access are used.
(28) Laundry area means an area containing or designed to contain either a laundry tray, clothes washer and/or clothes dryer.
(29) Lighting outlet means an outlet intended for the direct connection of a lampholder, a lighting fixture, or a pendant cord terminating in a lampholder.
(30) Manufactured home accessory building or structure means any awning, cabana, ramada, storage cabinet, carport, fence, windbreak or porch established for the use of the occupant of the manufactured home upon a manufactured home lot.
(31) Manufactured home service equipment means the equipment containing the disconnecting means, overcurrent protective devices, and receptacles or other means for connecting a manufactured home feeder assembly.
(32) Outlet means a point on the wiring system at which current is taken to supply utilization equipment.
(33) Panelboard means a single panel or group of panel units designed for assembly in the form of a single panel; including buses, automatic overcurrent protective devices, and with or without switches for the control of light, heat, or power circuits; designed to be placed in a cabinet or cutout box placed in or against a wall or partition and accessible only from the front.
(34) Raceway means any channel for holding wires, cables, or busbars that is designed expressly for, and used solely for, this purpose. Raceways may be of metal or insulating material, and the term includes rigid metal conduit, rigid nonmetallic conduit, flexible metal conduit, electrical metallic tubing, underfloor raceways, cellular concrete floor raceways, cellular metal floor raceways, surface raceways, structural raceways, wireways, and busways.
(35) Raintight means so constructed or protected that exposure to a beating rain will not result in the entrance of water.
(36) Readily accessible means capable of being reached quickly for operation, renewal, or inspection, without requiring those to whom ready access is requisite to climb over or remove obstacles or to resort to portable ladders, chairs, etc. (See Accessible.)
(37) Receptacle means a contact device installed at the outlet for the connection of an attachment plug. A single receptacle is a single contact device with no other contact device on the same yoke. A multiple receptacle is a device with two or more contact devices on the same yoke.
(38) Receptacle outlet means an outlet where one or more receptacles are installed.
(39) Utilization equipment means equipment that utilizes electric energy for electronic, electromechanical, chemical, heating, lighting, or similar purposes.
(40) Voltage (of a circuit) means the greatest root-mean-square (effective) difference of potential between any two conductors of the circuit concerned. Some systems, such as 3-phase 4-wire, single-phase 3-wire, and 3-wire direct-current may have various circuits of various voltages.
(41) Weatherproof means so constructed or protected that exposure to the weather will not interfere with successful operation. Rainproof, raintight, or watertight equipment can fulfill the requirements for weatherproof where varying weather conditions other than wetness, such as snow, ice, dust, or temperature extremes, are not a factor.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 78 FR 73989, Dec. 9, 2013]
§ 3280.803
Power supply.
(a) The power supply to the manufactured home shall be a feeder assembly consisting of not more than one listed 50 ampere manufactured home power-supply cords, or a permanently installed circuit. A manufactured home that is factory-equipped with gas or oil-fired central heating equipment and cooking appliances shall be permitted to be provided with a listed manufactured home power-supply cord rated 40 amperes.
(b) If the manufactured home has a power-supply cord, it shall be permanently attached to the distribution panelboard or to a junction box permanently connected to the distribution panelboard, with the free end terminating in an attachment plug cap.
(c) Cords with adapters and pigtail ends, extension cords, and similar items shall not be attached to, or shipped with, a manufactured home.
(d) A suitable clamp or the equivalent must be provided at the distribution panelboard knockout to afford strain relief for the cord to prevent strain from being transmitted to the terminals when the power supply cord is handled in its intended manner.
(e) The cord shall be of an approved type with four conductors, one of which shall be identified by a continuous green color or a continuous green color with one or more yellow stripes for use as the grounding conductor.
(f) The attachment plug cap must be a 3-pole, 4-wire, grounding type, rated 50 amperes, 125/250 volts, intended for use with the 50-ampere, 125/250-volt receptacle configuration, as shown below. The cap must be listed, by itself or as part of a power-supply cord assembly, for the purpose, and must be molded to or installed on the flexible cord so that it is secured tightly to the cord at the point where the cord enters the attachment plug cap. If a right-angle cap is used, the configuration must be so oriented that the grounding member is farthest from the cord.
(g) The overall length of a power-supply cord, measured from the end of the cord, including bared leads, to the face of the attachment-plug cap shall not be less than 21 feet and shall not exceed 361/2 feet. The length of cord from the face of the attachment-plug cap to the point where the cord enters the manufactured home shall not be less than 20 feet.
(h) The power supply cord shall bear the following marking: “For use with manufactured homes—40 amperes” or “For use with manufactured homes—50 amperes.”
(i) Where the cord passes through walls or floors, it must be protected by means of conduits and bushings or the equivalent. The cord is permitted to be installed within the manufactured home walls, provided that a continuous raceway having a maximum size of 11/4 inch is installed from the branch-circuit panelboard to the underside of the manufactured home floor.
(j) Permanent provisions shall be made for the protection of the attachment-plug cap of the power supply cord and any connector cord assembly or receptacle against corrosion and mechanical damage if such devices are in an exterior location while the manufactured home is in transit.
(k) Where the calculated load exceeds 50 amperes or where a permanent feeder is used, the supply shall be by means of:
(1) One mast weatherhead installation installed in accordance with Article 230 of the National Electrical Code, NFPA No. 70-2005, containing four continuous insulated, color-coded, feeder conductors, one of which shall be an equipment grounding conductor; or
(2) A listed metal raceway or listed rigid nonmetallic conduit from the disconnecting means in the manufactured home to the underside of the manufactured home, with provisions for the attachment of a suitable junction box or fitting to the raceway on the underside of the manufactured home. The manufacturer must provide written installation instructions stating the proper feeder conductor sizes for the raceway and the size of the junction box to be used; or
(3) Service equipment installed in or on the manufactured home, provided that all of the following conditions are met:
(i) In its written installation instructions, the manufacturer must include information indicating that the home must be secured in place by an anchoring system or installed on and secured to a permanent foundation;
(ii) The installation of the service equipment complies with Article 230 of the National Electrical Code, NFPA 70-2005 (incorporated by reference, see § 3280.4). Exterior service equipment or the enclosure in which it is to be installed must be weatherproof, and conductors must be suitable for use in wet locations;
(iii) Means are provided for the connection of the grounding electrode conductor to the service equipment and routing it to the conductor outside the structure;
(iv) Bonding and grounding of the service must be in accordance with Article 250, NFPA 70-2005, National Electrical Code (incorporated by reference, see § 3280.4);
(v) The manufacturer must include in its installation instructions one method of grounding the service equipment at the installation site. The instructions must clearly state that other methods of grounding are found in Article 250 of NFPA 70-2005, National Electrical Code;
(vi) The minimum size grounding electrode conductor must be specified in the instructions; and
(vi) A red warning label must be mounted on or adjacent to the service equipment. The label must state the following: WARNING—DO NOT PROVIDE ELECTRICAL POWER UNTIL THE GROUNDING ELECTRODE(S) IS INSTALLED AND CONNECTED (SEE INSTALLATION INSTRUCTIONS).
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4589, Feb. 12, 1987; 58 FR 55019, Oct. 25, 1993; 70 FR 72051, Nov. 30, 2005; 78 FR 73990, Dec. 9, 2013]
§ 3280.804
Disconnecting means and branch-circuit protective equipment.
(a) The branch-circuit equipment is permitted to be combined with the disconnecting means as a single assembly. Such a combination is permitted to be designated as a distribution panelboard. If a fused distribution panelboard is used, the maximum fuse size for the mains shall be plainly marked, with the lettering at least 1/4-inch high and visible when fuses are changed. See Article 110-22 of NFPA 70-2005, National Electrical Code (incorporated by reference, see § 3280.4), concerning the identification of each disconnecting means and each service, feeder, or branch circuit at the point where it originated, and the type of marking needed.
(b) Plug fuses and fuseholders shall be tamper-resistant, Type “S,” enclosed in dead-front fuse panelboards. Electrical distribution panels containing circuit breakers shall also be dead-front type.
(c) Disconnecting means. A single disconnecting means must be provided in each manufactured home, consisting of a circuit breaker, or a switch and fuses and its accessories, installed in a readily accessible location near the point of entrance of the supply cord or conductors into the manufactured home. The main circuit breakers or fuses must be plainly marked “Main.” This equipment must contain a solderless type of grounding connector or bar for the purposes of grounding, with sufficient terminals for all grounding conductors. The neutral bar termination of the grounded circuit conductors must be insulated in accordance with § 3280.809(b).
(d) The disconnecting equipment shall have a rating suitable for the connected load. The distribution equipment, either circuit breaker or fused type, shall be located a minimum of 24 inches from the bottom of such equipment to the floor level of the manufactured home.
(e) A distribution panelboard employing a main circuit breaker must be rated not less than 50 amperes and employ a 2-pole circuit breaker rated 40 amperes for a 40-ampere supply cord, or 50 amperes for a 50-ampere supply cord. A distribution panelboard employing a disconnect switch and fuses must be rated not less than 60 amperes and must employ a single, 2-pole fuseholder rated not less than 60-amperes with 40- or 50-ampere main fuses for 40- or 50-ampere supply cords, respectively. The outside of the distribution panelboard must be plainly marked with the fuse size.
(f) The distribution panelboard must be located in an accessible location, and must not be located in a bathroom or a clothes closet. A clear working space at least 30 inches wide and 30 inches in front of the distribution panelboard must be provided. This space must extend from the floor to the top of the distribution panelboard. Where used as switches, circuit breakers must be installed so that the center of the grip of the operating handle of the circuit breaker, when in its highest position, will not be more than 6 feet, 7 inches above the floor.
(g) Branch-circuit distribution equipment shall be installed in each manufactured home and shall include overcurrent protection for each branch circuit consisting of either circuit breakers or fuses.
(1) The branch circuit overcurrent devices shall be rated:
(i) Not more than the circuit conductors; and
(ii) Not more than 150 percent of the rating of a single appliance rated 13.3 amperes or more which is supplied by an individual branch circuit; but
(iii) Not more than the fuse size marked on the air conditioner or other motor-operated appliance.
(h) A 15-ampere multiple receptacle shall be acceptable when connected to a 20-ampere laundry circuit.
(i) When circuit breakers are provided for branch-circuit protection 240 circuits shall be protected by 2-pole common or companion trip, or handle-tied paired circuit breakers.
(j) A 3 inch by 1-3/4 inch minimum size tag made of etched, metal-stamped or embossed brass, stainless steel, anodized or alclad aluminum not less than 0.020 inch thick, or other approval material (e.g., 0.005 inch plastic laminates) shall be permanently affixed on the outside adjacent to the feeder assembly entrance and shall read: This connection for 120/240 Volt, 3-Pole, 4-Wire, 60 Hertz, ____ Ampere Supply. The correct ampere rating shall be marked on the blank space.
(k) When a home is provided with installed service equipment, a single disconnecting means for disconnecting the branch circuit conductors from the service entrance conductors must be provided in accordance with Article 230, Part VI of the National Electrical Code, NFPA No. 70-2005. The disconnecting means shall be listed for use as service equipment. The disconnecting means may be combined with the disconnect required by § 3280.804(c). The disconnecting means shall be rated not more than the ampere supply or service capacity indicated on the tag required by paragraph (l) of this section.
(l) When a home is provided with installed service equipment, the electrical nameplate required by § 3280.804(j) shall read: “This connection for 120/240 volt, 3 pole, 3 wire, 60 Hertz, ____ Ampere Supply.” The correct ampere rating shall be marked in the blank space.
[40 FR 58752, Dec. 18, 1975, as amended at 42 FR 961, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 4589, Feb. 12, 1987; 58 FR 55019, Oct. 25, 1993; 70 FR 72051, Nov. 30, 2005; 78 FR 73990, Dec. 9, 2013]
§ 3280.805
Branch circuits required.
(a) The number of branch circuits required shall be determined in accordance with the following:
(1) Lighting, based on 3 volt-amperes per square foot times outside dimensions of the manufactured home (coupler excluded) divided by 120 volts times amperes to determine number of 15 or 20 ampere lighting area circuits. e.g. [3 × length × width—[120 × (15 or 20)] = number of 15 or 20 ampere circuits. Lighting circuits are permitted to serve built-in gas ovens with electric service for lights, clocks, or timers, or for listed cord-connected garbage disposal units.
(2) Small Appliances. For the small appliance load in kitchens, pantries, dining rooms, and breakfast rooms of manufactured homes, two or more 20-ampere appliance branch circuits, in addition to the branch circuit specified in paragraph (a)(1) of this section, must be provided for all receptacle outlets in these rooms, and such circuits must have no other outlets. Countertop receptacle outlets installed in the kitchen must be supplied by not less than two small appliance branch circuits. One or more of the small appliance branch circuits may also supply other receptacle outlets in the kitchen, pantry, dining room, and breakfast room. Receptacles installed solely for the electrical supply to an electric clock and receptacles installed to provide power for supplemental equipment and lighting on gas-fired ranges, ovens, or counter-mounted cooking units are not subject to the requirements of this paragraph (a)(2).
(3) General appliances (Including furnace, water heater, range, and central or room air conditioner, etc.). There shall be one or more circuits of adequate rating in accordance with the following:
(i) The ampere rating of fixed appliances must not exceed 50 percent of the circuit rating if lighting outlets are on the same circuit (receptacles in the kitchen, dining area, and laundry are not considered to be lighting outlets);
(ii) For fixed appliances on a circuit without lighting outlets, the sum of rated amperes shall not exceed the branch-circuit rating. Motor loads or other continuous duty loads shall not exceed 80 percent of the branch circuit rating.
(iii) The rating of a single cord and plug connected appliances on a circuit having no other outlets, shall not exceed 80 percent of the circuit rating.
(iv) The rating of the range branch circuit is based on the range demand as specified for ranges in § 3280.811(a)(5). For central air conditioning, see Article 440 of the National Electrical Code, NFPA No. 70-2005.
(v) Where a laundry area is provided, a 20 ampere branch circuit shall be provided to supply laundry receptacle outlets. This circuit shall have no other outlets. See § 3280.806(a)(7).
(vi) Bathroom receptacle outlets must be supplied by at least one 20-ampere branch circuit. Such circuits must have no other outlets, except that it is permissible to place the receptacle outlet for a heat tape or pipe heating cable required by § 3280.806(d)(10) on a bathroom circuit. (See § 3280.806(b).)
(b) [Reserved]
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55020, Oct. 25, 1993; 70 FR 72051, Nov. 30, 2005; 78 FR 73991, Dec. 9, 2013]
§ 3280.806
Receptacle outlets.
(a) All receptacle outlets shall be:
(1) Of grounding type;
(2) Installed according to Article 406.3 of the National Electrical Code, NFPA No. 70-2005.
(3) Except when supplying specific appliances, be parallel-blade, 15-ampere, 125-volt, either single or duplex.
(b) All 125-volt, single-phase, 15- and 20-ampere receptacle outlets installed outdoors, or in compartments accessible from outside the manufactured home, and in bathrooms, including receptacles in light fixtures, must have ground-fault circuit-interrupter protection for personnel. Ground-fault circuit-interrupter protection for personnel must be provided for receptacles serving countertops in kitchens and receptacle outlets located within 6 feet of a wet bar sink, except for receptacles installed for appliances in dedicated spaces, such as dishwashers, disposals, refrigerators, freezers, and laundry equipment.
(c) There shall be an outlet of the grounding type for each cord-connected fixed appliance installed.
(d) Receptacle outlets required. Except in the bath, closet, and hall areas, receptacle outlets must be installed at wall spaces 2 feet or more wide, so that no point along the floor line is more than 6 feet, measured horizontally, from an outlet in that space. Receptacle outlets in floors shall not be counted as part of the required number of receptacle outlets, unless located within 18 inches of the wall. In addition, a receptacle outlet must be installed in the following locations:
(1) Over or adjacent to counter tops in the kitchen (at least one on each side of the sink if counter tops are on each side and 12 inches or over in width).
(2) Adjacent to the refrigerator and free-standing gas-range space. A duplex receptacle may serve as the outlet for a countertop and a refrigerator.
(3) At counter top spaces for built-in vanities.
(4) At counter top spaces under wall-mounted cabinets.
(5) In the wall, at the nearest point where a bar type counter attaches to the wall.
(6) In the wall at the nearest point where a fixed room divider attaches to the wall.
(7) In laundry areas within 6 feet of the intended location of the appliance(s).
(8) At least one receptacle outlet shall be installed outdoors.
(9) At least one wall receptacle outlet shall be installed in bathrooms within 36 inches (914 mm) of the outside edge of each basin. The receptacle outlet must be located on a wall that is adjacent to the basin location. This receptacle is in addition to any receptacle that is part of a lighting fixture or appliance. The receptacle must not be enclosed within a bathroom cabinet or vanity.
(10) On the underside of the home for the connection of pipe heating cable(s) or heat tape(s), and the outlet must:
(i) Be located within 2 feet of the cold water inlet;
(ii) Be connected to an interior branch circuit, other than a small appliance branch circuit;
(iii) Be located on a circuit where all of the outlets are on the load side of the ground-fault circuit-interrupter protection for personnel; and
(iv) Not be considered as the receptacle outlet required by paragraph (8) of this section.
(11) Receptacle outlets are not required in the following locations:
(i) Wall space occupied by built-in kitchen or wardrobe cabinets,
(ii) Wall space behind doors which may be opened fully against a wall surface,
(iii) Room dividers of the lattice type, less than 8 feet long, not solid within 6 inches of the floor,
(iv) Wall space afforded by bar type counters.
(e) Receptacle outlets shall not be installed in or within reach (30 inches) of a shower or bathtub space.
(f) Receptacle outlets shall not be installed above electric baseboard heaters.
(g) Receptacles must not be in a face-up position in any countertop.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55020, Oct. 25, 1993; 70 FR 72052, Nov. 30, 2005; 78 FR 73991, Dec. 9, 2013]
§ 3280.807
Fixtures and appliances.
(a) Electrical materials, devices, appliances, fittings, and other equipment installed, intended for use in, or attached to the manufactured home shall be approved for the application and shall be connected in an approved manner when in service. Facilities shall be provided to securely fasten appliances when the manufactured home is in transit. (See § 3280.809.)
(b) Specifically listed pendant-type fixtures or pendant cords shall be permitted in manufactured homes.
(c) Where a lighting fixture is installed over a bathtub or in a shower stall, it must be listed for wet locations. [See also Article 410.4(D) of the National Electrical Code NFPA No. 70-2005.]
(d) The switch for shower lighting fixtures and exhaust fans located over a tub or in a shower stall shall be located outside the tub shower space. (See § 3280.806(e).)
(e) Any combustible wall or ceiling finish exposed between the edge of a fixture canopy, or pan and an outlet box shall be covered with non-combustible or limited combustible material.
(f) Every appliance shall be accessible for inspection, service, repair, or replacement without removal of permanent construction.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 52 FR 35543, Sept. 22, 1987; 58 FR 55020, Oct. 25, 1993; 70 FR 72052, Nov. 30, 2005; 78 FR 73991, Dec. 9, 2013]
§ 3280.808
Wiring methods and materials.
(a) Except as specifically permitted by this part, the wiring methods and materials specified in the National Electrical Code, NFPA No. 70-2005, must be used in manufactured homes.
(b) Nonmetallic outlet boxes shall be acceptable only with nonmetallic cable.
(c) Nonmetallic cable located 15 inches or less above the floor, if exposed, shall be protected from physical damage by covering boards, guard strips, or conduit. Cable likely to be damaged by stowage shall be so protected in all cases.
(d) Nonmetallic sheathed cable shall be secured by staples, straps, or similar fittings so designed and installed as not to injure any cable. Cable shall be secured in place at intervals not exceeding 41/2 feet and within 12 inches from every cabinet, box or fitting.
(e) Metal-clad and nonmetallic cables shall be permitted to pass through the centers of the wide side of 2-inch by 4-inch studs. However, they shall be protected where they pass through 2-inch by 2-inch studs or at other studs or frames where the cable or armor would be less than 11/2 inches from the inside or outside surface of the studs when the wall covering materials are in contact with the studs. Steel plates on each side of the cable, or a tube, with not less than No. 16 MSG wall thickness shall be required to protect the cable. These plates or tubes shall be securely held in place.
(f) Where metal faceplates are used, they must be effectively grounded.
(g) If the range, clothes dryer, or similar appliance is connected by metalclad cable or flexible conduit, a length of not less than three feet of free cable or conduit shall be provided to permit moving the appliance. Type NM or Type SE cable shall not be used to connect a range or a dryer. This shall not prohibit the use of Type NM or Type SE cable between the branch circuit overcurrent protective device and a junction box or range or dryer receptacle.
(h) Where rigid metal conduit or intermediate metal conduit is terminated at an enclosure with a locknut and bushing connection, two locknuts must be provided, one inside and one outside of the enclosure. Rigid nonmetallic conduit or electrical nonmetallic tubing is permitted. All cut ends of conduit and tubing must be reamed or otherwise finished to remove rough edges.
(i) Switches must be rated as follows:
(1) For lighting circuits, switches must be rated not less than 10 amperes, 120 to 125 volts, and in no case less than the connected load.
(2) For motors or other loads, switches shall have ampere or horsepower ratings, or both, adequate for loads controlled. (An “AC general-use” snap switch shall be permitted to control a motor 2 horsepower or less with full-load current not over 80 percent of the switch ampere rating).
(j) At least 4 inches of free conductor shall be left at each outlet box except where conductors are intended to loop without joints.
(k) When outdoor or under-chassis line-voltage (120 volts, nominal or higher) wiring is exposed to moisture or physical damage, it must be protected by rigid metal conduit or intermediate metal conduit. The conductors must be suitable for wet locations. Electrical metallic tubing or rigid nonmetallic conduit is permitted to be used when closely routed against frames and equipment enclosures.
(l) Outlet boxes of dimensions less than those required in Table 314.16(A) of the National Electrical Code, NFPA No. 70-2005, are permitted provided the box has been tested and approved for that purpose.
(m) Boxes, fittings, and cabinets shall be securely fastened in place, and shall be supported from a structural member of the home, either directly or by using a substantial brace. Snap-in type boxes provided with special wall or ceiling brackets that securely fasten boxes in walls or ceilings shall be permitted.
(n) Outlet boxes must fit closely to openings in combustible walls and ceilings and must be flush with the finish surface or project therefrom. In walls and ceilings of noncombustible material, outlet boxes and fittings must be installed so that the front edge of the box or fitting will not be set back from the finished surface more than 1/4 inch. Plaster, drywall, or plasterboard surfaces that are broken or incomplete must be repaired so that there will be no gaps or open spaces greater than 1/8 inch at the edge of the box or fitting.
(o) Appliances having branch-circuit terminal connections which operate at temperatures higher than 60 °C (140 °F) shall have circuit conductors as described in paragraphs (p) (1) and (2) of this section:
(1) Branch-circuit conductors having an insulation suitable for the temperature encountered shall be permitted to run directly to the appliance.
(2) Conductors having an insulation suitable for the temperature encountered may be run from the appliance terminal connections to a readily accessible outlet box placed at least one foot from the appliance. If provided, these conductors must be in a suitable raceway or Type AC or MC cable, of at least 18 inches but not more than 6 feet in length.
(p) A substantial brace for securing a box, fitting, or cabinet must be as described in the National Electrical Code, NFPA 70-2005, Article 314.23(B), or the brace, including the fastening mechanism to attach the brace to the home structure, must withstand a force of 50 lbs. applied to the brace at the intended point(s) of attachment for the box in a direction perpendicular to the surface on which the box is installed.
(q) Where the sheathing of NM cable has been cut or damaged and visual inspection reveals that the conductor and its insulation has not been damaged, it shall be permitted to repair the cable sheath with electrical tape which provides equivalent protection to the sheath.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55020, Oct. 25, 1993; 70 FR 72052, Nov. 30, 2005; 78 FR 73991, Dec. 9, 2013]
§ 3280.809
Grounding.
(a) General. Grounding of both electrical and nonelectrical metal parts in a manufactured home shall be through connection to a grounding bus in the manufactured home distribution panelboard. The grounding bus shall be grounded through the green-colored conductor in the supply cord or the feeder wiring to the service ground in the service-entrance equipment located adjacent to the manufactured home location. Neither the frame of the manufactured home nor the frame of any appliance shall be connected to the neutral conductor in the manufactured home.
(b) Insulated neutral. (1) The grounded circuit conductor (neutral) shall be insulated from the grounding conductors and from equipment enclosures and other grounded parts. The grounded (neutral) circuit terminals in the distribution panelboard and in ranges, clothes dryers, counter-mounted cooking units, and wall-mounted ovens shall be insulated from the equipment enclosure. Bonding screws, straps, or buses in the distribution panelboard or in appliances shall be removed and discarded. However, when service equipment is installed on the manufactured home, the neutral and the ground bus may be connected in the distribution panel.
(2) Connection of ranges and clothes dryers with 120/240 volt, 3-wire ratings shall be made with 4 conductor cord and 3 pole, 4-wire grounding type plugs, or by type AC metal clad conductors enclosed in flexible metal conduit. For 120 volt rated devices a 3-conductor cord and a 2-pole, 3-wire grounding type plug shall be permitted.
(c) Equipment grounding means. (1) The green-colored grounding wire in the supply cord or permanent feeder wiring shall be connected to the grounding bus in the distribution panelboard or disconnecting means.
(2) In the electrical system, all exposed metal parts, enclosures, frames, lamp fixture canopies, etc., shall be effectively bonded to the grounding terminal or enclosure of the distribution panelboard.
(3) Cord-connected appliances, such as washing machines, clothes dryers, refrigerators, and the electrical system of gas ranges, etc., shall be grounded by means of an approved cord with grounding conductor and grounding-type attachment plug.
(d) Bonding of noncurrent-carrying metal parts. (1) All exposed noncurrent-carrying metal parts that may become energized shall be effectively bonded to the grounding terminal or enclosure of the distribution panelboard. A bonding conductor shall be connected between each distribution panelboard and an accessible terminal on the chassis.
(2) Grounding terminals shall be of the solderless type and approved as pressure-terminal connectors recognized for the wire size used. Star washers or other approved paint-penetrating fitting shall be used to bond terminals to chassis or other coated areas. The bonding conductor shall be solid or stranded, insulated or bare and shall be No. 8 copper minimum, or equal. The bonding conductor shall be routed so as not to be exposed to physical damage. Protection can be afforded by the configuration of the chassis.
(3) Metallic gas, water and waste pipes and metallic air-circulating ducts shall be considered bonded if they are connected to the terminal on the chassis (see § 3280.809) by clamps, solderless connectors, or by suitable grounding-type straps.
(4) Any metallic roof and exterior covering shall be considered bonded if (i) the metal panels overlap one another and are securely attached to the wood or metal frame parts by metallic fasteners, and (ii) if the lower panel of the metallic exterior covering is secured by metallic fasteners at a cross member of the chassis by two metal straps per manufactured home unit or section at opposite ends. The bonding strap material shall be a minimum of 4 inches in width of material equivalent to the skin or a material of equal or better electrical conductivity. The straps shall be fastened with paint-penetrating fittings (such as screws and star washers or equivalent).
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55020, Oct. 25, 1993]
§ 3280.810
Electrical testing.
(a) Dielectric strength test. The wiring of each manufactured home shall be subjected to a 1-minute, 900 to 1079 volt dielectric strength test (with all switches closed) between live parts and the manufactured home ground, and neutral and the manufactured home ground. Alternatively, the test may be performed at 1080 to 1250 volts for 1 second. This test shall be performed after branch circuits are complete and after fixtures or appliances are installed. Fixtures or appliances which are listed shall not be required to withstand the dielectric strength test.
(b) Each manufactured home shall be subject to:
(1) A continuity test to assure that metallic parts are properly bonded;
(2) Operational test to demonstrate that all equipment, except water heaters, electric furnaces, dishwashers, clothes washers/dryers, and portable appliances, is connected and in working order; and
(3) Polarity checks to determine that connections have been properly made. Visual verification shall be an acceptable check.
[58 FR 55020, Oct. 25, 1993]
§ 3280.811
Calculations.
(a) The following method shall be employed in computing the supply cord and distribution-panelboard load for each feeder assembly for each manufactured home and shall be based on a 3-wire, 120/240 volt supply with 120 volt loads balanced between the two legs of the 3-wire system. The total load for determining power supply by this method is the summation of:
(1) Lighting and small appliance load as calculated below:
(i) Lighting volt-amperes: Length time width of manufactured home (outside dimensions exclusive of coupler) times 3 volt-amperes per square foot; e.g. Length × width × 3 = lighting volt-amperes.
(ii) Small appliance volt-amperes: Number of circuits time 1,500 volt-amperes for each 20-ampere appliance receptacle circuit (see definition of “Appliance Portable” with Note): e.g. Number of circuits × 1,500 = small appliance volt-amperes.
(iii) Total volts-amperes: Lighting volts-amperes plus small appliance = total volt-amperes.
(iv) First 3,000 total volts-amperes at 100 percent plus remainder at 35 percent = watts to be divided by 240 volts to obtain current (amperes) per leg.
(2) Nameplate amperes for motors and heater loads (exhaust fans, air conditioners, electric, gas, or oil heating). Omit smaller of air conditioning and heating except include blower motor if used as air conditioner evaporator motor. When an air conditioner is not installed and a 40-ampere power supply cord is provided, allow 15 amperes per leg for air conditioning.
(3) 25 percent of current of largest motor in paragraph (a)(2) of this section.
(4) Total of nameplate amperes for: Disposal, dishwasher, water heater, clothes dryer, wall-mounted oven, cooking units. Where number of these appliances exceeds three, use 75 percent of total.
(5) Derive amperes for free-standing range (as distinguished from separate ovens and cooking units) by dividing values below by 240 volts.
Nameplate rating (in watts) | Use (in watts)
10,000 or less | 80 percent of rating.
10,001 to 12,500 | 8,000.
12,501 to 13,500 | 8,400.
13,501 to 14,500 | 8,800.
14,501 to 15,500 | 9,200.
15,501 to 16,500 | 9,600.
16,501 to 17,500 | 10,000.
(6) If outlets or circuits are provided for other than factory-installed appliances, include the anticipated load. The following example is given to illustrate the application of this Method of Calculation:

Example:
A manufactured home is 70 × 10 feet and has two portable appliance circuits, a 1000 volt-ampere 240 volt heater, a 200 volt-ampere 120 volt exhaust fan, a 400 volts-ampere 120 volt dishwasher and a 7000 volt-ampere electric range.
Lighting and small appliance load | Volt-ampheres
Lighting 70 × 10 × 3 | 2,100
Small Appliance | 3,000
Total | 5,100
1st. 3,000 Volt-Ampheres at 100% | 3,000
Remainder (5,100 −3,000 = 2,100, at 35% | 735
Total | 3,735
| Amperes per leg A | Amperes per leg B
Lighting and small Appliance | 15.5 | 15.5
Heater 240 volt | 4.1 | 4.1
Fan 120 volt | 1.7 |
Dishwasher 120 volt | | 3.3
Range | 23.3 | 23.3
Total | 44.6 | 46.2
Note: Based on the higher current calculated for either leg, use one 50-A supply cord.
(b) The following is an optional method of calculation for lighting and appliance loads for manufactured homes served by single 3-wire 120/240 volt set of feeder conductors with an ampacity of 100 or greater. The total load for determining the feeder ampacity may be computed in accordance with the following table instead of the method previously specified. Feeder conductors whose demand load is determined by this optional calculation are permitted to have the neutral load determined by Article 220.61 of the National Electrical Code, NFPA No. 70-2005. The loads identified in the table as “other load” and as “Remainder of other load” must include the following:
(1) 1500 volt-amperes for each 2-wire, 20-ampere small appliance branch circuit and each laundry branch circuit specified.
(2) 3 volt-amperes per square foot for general lighting and general-use receptacles.
(3) The nameplate rating of all fixed appliances, ranges, wall-mounted ovens, counter-mounted cooking units, and including 4 or more separately controlled space heating loads.
(4) The nameplate ampere or kVA rating of all motors and of all low-power-factor loads.
(5) The largest of the following:
(i) Air conditioning load;
(ii) The 65 percent diversified demand of the central electric space heating load;
(iii) The 65 percent diversified demand of the load of less than four separately-controlled electric space heating units.
(iv) The connected load of four or more separately-controlled electric space heating units.
Optional Calculation for Manufactured Homes With 110-Ampere or Larger Service
Load (in kilowatt or kilovoltampere) | Demand factor (percent)
Air-conditioning and cooling including heat pump compressors | 100
Central electric space heating | 65
Less than 4 separately controlled electric space heating units | 65
1st 10 kW of all other load | 100
Remainder of other load | 40
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55021, Oct. 25, 1993; 70 FR 72052, Nov. 30, 2005]
§ 3280.812
Wiring of expandable units and dual units.
(a) Expandable or multiple unit manufactured homes shall use fixed-type wiring methods and materials for connecting such units to each other.
(b) Expandable or multiple unit manufactured homes not having permanently installed feeders and which are to be moved from one location to another, shall be permitted to have disconnecting means with branch circuit protective equipment in each unit when so located that after assembly or joining together of units the requirements of § 3280.803 will be met.
§ 3280.813
Outdoor outlets, fixtures, air-conditioning equipment, etc.
(a) Outdoor fixtures and equipment shall be listed for use in wet locations, except that if located on the underside of the home or located under roof extensions or similarly protected locations, they may be listed for use in damp locations.
(b) A manufactured home provided with a branch circuit designed to energize outside heating equipment or air-conditioning equipment, other than room air conditioners, or both, located outside the manufactured home, other than room air conditioners, must have such branch-circuit conductors terminate in a listed outlet box, or disconnecting means, located on the outside of the manufactured home.
(1) A label must be permanently affixed adjacent to the outlet box. The label must be not less than 0.020-inches thick etched brass, stainless steel, anodized or alclad aluminum, or equivalent, and must not be less than 3 inches × 13/4 inches in size.
(2)(i) The label must include the correct voltage and ampere rating and the following information:
THIS CONNECTION IS FOR HEATING AND/OR AIR-CONDITIONING EQUIPMENT. THE BRANCH CIRCUIT IS RATED AT NOT MORE THAN__AMPERES, AT__VOLTS, 60-HERTZ,__CONDUCTOR AMPACITY. A DISCONNECTING MEANS IS LOCATED WITHIN SIGHT OF THE EQUIPMENT.
(ii) The correct voltage and ampere rating shall be given. The tag must be not less than 0.020-inches thick etched brass, stainless steel, anodized or alclad aluminum, or equivalent. The tag must have a minimum size of not less than 3 inches × 13/4 inches.
[40 FR 58752, Dec. 18, 1975, as amended at 42 FR 961, Jan. 4, 1977. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55021, Oct. 25, 1993; 78 FR 73992, Dec. 9, 2013]
§ 3280.814
Painting of wiring.
During painting or staining of the manufactured home, it shall be permitted to paint metal raceways (except where grounding continuity would be reduced) or the sheath of the nonmetallic cable. Some arrangement, however, shall be made so that no paint shall be applied to the individual wires, as the color coding may be obliterated by the paint.
§ 3280.815
Polarization.
(a)(1) Except as provided in paragraph (a)(2) of this section, the white conductor must be employed for the grounded (neutral) circuit conductors only and must be connected to the white terminal or lead on receptacle outlets and fixtures. The grounded conductor must be the unswitched wire in switched circuits.
(2) A cable containing an insulated conductor with a white or natural gray outer finish or a marking of three continuous white stripes may be used for single-pole, three-way, or four-way switch loops, where this conductor is used for the supply to the switch, but not as a return conductor from the switch to the switched outlet. In these applications, the conductor with white or natural gray insulation or with three continuous white stripes must be permanently re-identified to indicate its use by painting or other effective means at its terminations and at each location where the conductor is visible and accessible.
(b) If the identified (white) conductor of a cable is used for other than grounded conductors or for other than switch loops as explained above (for a 240 volt circuit for example), the conductor shall be finished in a color other than white at each outlet where the conductors are visible and accessible.
(c) Green-colored wires or green with yellow stripe shall be used for grounding conductors only.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 58 FR 55021, Oct. 25, 1993; 78 FR 73992, Dec. 9, 2013]
§ 3280.816
Examination of equipment for safety.
The examination or inspection of equipment for safety, according to this standard, shall be conducted under uniform conditions and by organizations properly equipped and qualified for experimental testing, inspections of the run of goods at factories, and service-value determinations through field examinations.

Subpart J—Transportation
§ 3280.901
Scope.
Subpart J of this standard covers the general requirement for designing the structure of the manufactured home to fully withstand the adverse effects of transportation shock and vibration without degradation of the integrated structure or of its component parts and the specific requirements pertaining to the transportation system and its relationship to the structure.
§ 3280.902
Definitions.
(a) Chassis means the entire transportation system comprising the following subsystems: drawbar and coupling mechanism, frame, running gear assembly, and lights.
(b) Drawbar and coupling mechanism means the rigid assembly, (usually an A frame) upon which is mounted a coupling mechanism, which connects the manufactured home's frame to the towing vehicle.
(c) Frame means the fabricated rigid substructure which provides considerable support to the affixed manufactured home structure both during transport and on-site; and also provides a platform for securement of the running gear assembly, the drawbar and coupling mechanism.
(d) Running gear assembly means the subsystem consisting of suspension springs, axles, bearings, wheels, hubs, tires, and brakes, with their related hardware.
(e) Lights means those safety lights and associated wiring required by applicable U.S. Department of Transportation regulations.
(f) Transportation system, (Same as chassis, above).
(g) Highway, includes all roads and streets to be legally used in transporting the manufactured home.
[40 FR 58752, Dec. 18, 1975. Redesignated at 44 FR 20679, Apr. 6, 1979, as amended at 47 FR 28093, June 29, 1982]
§ 3280.903
General requirements for designing the structure to withstand transportation shock and vibration.
(a) The cumulative effect of highway transportation shock and vibration upon a manufactured home structure may result in incremental degradation of its designed performance in terms of providing a safe, healthy and durable dwelling. Therefore, the manufactured home shall be designed, in terms of its structural, plumbing, mechanical and electrical systems, to fully withstand such transportation forces during its intended life. (See §§ 3280.303(c) and 3280.305(a)).
(b) Particular attention shall be given to maintaining watertight integrity and conserving energy by assuring that structural components in the roof and walls (and their interfaces with vents, windows, doors, etc.) are capable of resisting highway shock and vibration forces during primary and subsequent secondary transportation moves.
(c) In place of an engineering analysis, either of the following may be accepted:
(1) Documented technical data of suitable highway tests which were conducted to simulate transportation loads and conditions; or
(2) Acceptable documented evidence of actual transportation experience which meets the intent of this subpart.
§ 3280.904
Specific requirements for designing the transportation system.
(a) General. The entire system (frame, drawbar and coupling mechanism, running gear assembly, and lights) shall be designed and constructed as an integrated, balanced and durable unit which is safe and suitable for its specified use during the intended life of the manufactured home. In operation, the transportation system (supporting the manufactured home structure and its contents) shall effectively respond to the control of the braking, while traveling at applicable towing vehicle in terms of tracking and highway speeds and in normal highway traffic conditions.

Note:
While the majority of manufactured homes utilize a fabricated steel frame assembly, upon which the manufactured home structure is constructed, it is not the intent of this standard to limit innovation. Therefore, other concepts, such as integrating the frame function into the manufactured home structure, are acceptable provided that such design meets the intent and requirements of this part).
(b) Specific requirements—(1) Drawbar. The drawbar shall be constructed of sufficient strength, rigidity and durability to safely withstand those dynamic forces experienced during highway transportation. It shall be securely fastened to the manufactured home frame by either a continuous weld or by bolting.
(2) Coupling mechanism. The coupling mechanism (which is usually of the socket type) shall be securely fastened to the drawbar in such a manner as to assure safe and effective transfer of the maximum loads, including dynamic loads, between the manufactured home structure and the hitch-assembly of the towing vehicle. The coupling shall be equipped with a manually operated mechanism so adapted as to prevent disengagement of the unit while in operation. The coupling shall be so designed that it can be disconnected regardless of the angle of the manufactured home to the towing vehicle. With the manufactured home parked on level ground, the center of the socket of the coupler shall not be less than 20 inches nor more than 26 inches from ground level.
(3) Chassis. The chassis, in conjunction with the manufactured home structure, shall be designed and constructed to effectively sustain the designed loads consisting of the dead load plus a minimum of 3 pounds per square foot floor load, (example: free-standing range, refrigerator, and loose furniture) and the superimposed dynamic load resulting from highway movement but shall not be required to exceed twice the dead load. The integrated design shall be capable of insuring rigidity and structural integrity of the complete manufactured home structure and to insure against deformation of structural or finish members during the intended life of the home.
(4) Running gear assembly. (i) The running gear assembly, as part of the chassis, shall be designed to perform, as a balanced system, in order to effectively sustain the designed loads set forth in § 3280.904(b)(3) and to provide for durable dependable safe mobility of the manufactured home. It shall be designed to accept shock and vibration, both from the highway and the towing vehicle and effectively dampen these forces so as to protect the manufactured home structure from damage and fatigue. Its components shall be designed to facilitate routine maintenance, inspection and replacement.
(ii) Location of the running gear assembly shall be determined by documented engineering analysis, taking into account the gross weight (including all contents), total length of the manufactured home, the necessary coupling hitch weight, span distance, and turning radius. The coupling weight shall be not less than 12 percent nor more than 25 percent of the gross weight.
(5) Spring assemblies. Spring assemblies (springs, hangers, shackles, bushings and mounting bolts) shall be capable of withstanding all the design loads as outlined in § 3280.904(b)(3) without exceeding maximum allowable stresses for design spring assembly life as recommended by the spring assembly manufacturer. The capacity of the spring system shall assure, that under maximum operating load conditions, sufficient clearance shall be maintained between the tire and manufactured home frame or structure to permit unimpeded wheel movement and for changing tires.
(6) Axles. Axles, and their connecting hardware, shall be capable of withstanding all of the design loads outlined in § 3280.904(b)(3) without exceeding maximum allowable stresses for design axle life as recommended by the axle manufacturer. The number of axles required to provide a safe tow and good ride characteristics shall be determined and documented by engineering analysis. Those alternatives listed in § 3280.903(c) may be accepted in place of such an analysis.
(7) Hubs and bearings. Hubs and bearings shall meet the requirements of § 3280.904(b)(3) and good engineering practice. Both of these components shall be accessible for inspection, routine maintenance and replacement of parts.
(8) Tires, wheels and rims. Tires, wheels and rims shall meet the requirements of § 3280.904(b)(3). Tires shall be selected for anticipated usage.
(9) Brake assemblies. (i) The number, type, size and design of brake assemblies required to assist the towing vehicle in providing effective control and stopping of the manufactured home shall be determined and documented by engineering analysis. Those alternatives listed in § 3280.903(c) may be accepted in place of such an analysis.
(ii) Brakes on the towing vehicle and the manufactured home shall be capable of assuring that the maximum stopping distance from an initial velocity of 20 miles per hour does not exceed 40 feet (U.S. Department of Transportation Regulations).
(10) Lights and associated wiring. Highway safety electrical lights and associated wiring shall conform to applicable Federal requirements in terms of location and performance. The manufacturer shall have the option of meeting this requirement by utilizing a temporary light/wiring harness provided by the manufactured home transportation carrier.