[Federal Register Volume 67, Number 79 (Wednesday, April 24, 2002)]
[Rules and Regulations]
[Pages 20400-20403]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-9860]



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Part IV





Housing and Urban Development Department





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24 CFR Part 3280



Condensation Control for Exterior Walls of Manufactured Homes Sited in 
Humid and Fringe Climates; Waiver; Final Rule

  Federal Register / Vol. 67, No. 79 / Wednesday, April 24, 2002 / 
Rules and Regulations  

[[Page 20400]]


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DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT

24 CFR Part 3280

[Docket No. FR-4578-F-02]


Condensation Control for Exterior Walls of Manufactured Homes 
Sited in Humid and Fringe Climates; Waiver

AGENCY: Office of the Assistant Secretary for Housing--Federal Housing 
Commissioner, HUD.

ACTION: Final waiver.

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SUMMARY: This document advises the public that HUD is issuing a waiver 
of its regulations regarding the condensation control provisions for 
exterior walls of the manufactured home construction and safety 
standards. By this action, HUD is waiving certain provisions of these 
regulations to permit manufacturers, at their option, to utilize the 
alternatives provided in this notice to reduce the problems currently 
being experienced in humid and fringe climate areas. Presently, there 
are no provisions in HUD's regulations that separately address 
condensation control and vapor retarder requirements for manufactured 
homes sited in warm, moist climates of the South Atlantic and Gulf 
Regions. Based on information provided by the States and the public, 
HUD has concluded there is an immediate need to recognize alternate 
requirements for exterior walls in these humid and fringe climate areas 
that help prevent moisture damage due to condensation. By this action, 
HUD is finalizing its previously announced proposed waiver. This waiver 
will be in place while HUD considers a more permanent change to the 
standards.

EFFECTIVE DATE: April 24, 2002.

FOR FURTHER INFORMATION CONTACT: Elizabeth A. Cocke, Director, 
Manufactured Housing and Standards Division, Office of Consumer and 
Regulatory Affairs, Room 9156, Department of Housing and Urban 
Development, 451 Seventh Street SW, Washington, DC 20410-8000; 
telephone (202) 708-6409 (this is not a toll-free telephone number). 
Hearing and speech-impaired individuals may access this telephone 
number via TTY by calling the toll-free Federal Information Relay 
Service at 1-800-877-8339.

SUPPLEMENTARY INFORMATION:

I. Background

    The Department published a proposed waiver to 24 CFR 3280.504 of 
the Manufactured Home Construction and Safety Standards on March 30, 
2000 (65 FR 17110). The proposed waiver was issued in response to 
information received from manufacturers and certain State 
Administrative Agencies (SAAs) in southeastern States concerning a 
recent increase in the number and severity of consumer complaints 
caused primarily by moisture build-up and condensation in homes located 
in the south. They suggest this increase in complaints coincides with 
the Department's implementing more stringent energy efficiency 
requirements in its regulations regarding manufactured home 
construction and safety standards located at 24 CFR part 3280 (referred 
to as the ``Standards'').
    At present, Sec. 3280.504 of the Standards does not distinguish 
among climates for requirements for condensation control and 
installation of vapor barriers. [The term ``vapor barrier'' is now 
commonly referred to as a ``vapor retarder''. Accordingly, the term 
``vapor retarder'' will be used in all subsequent references throughout 
the text of this waiver.] Thus, for example, the Standards do not 
separately address homes placed in humid and fringe environments or 
climates, which are predominantly located in the southeastern part of 
the United States. In these climates, it may be beneficial to prevent 
the outside, moisture-laden air from entering through the warm 
(exterior) side of the home's exterior wall and condensing and 
collecting on the cold (living space or interior) side of the wall 
assembly. One means of preventing moisture from entering the exterior 
wall cavity from the outside, would be to install a vapor retarder on 
the warm or exterior side of the wall instead of on the interior or 
living space side of the exterior wall.
    The interior surface of the exterior wall should also then be 
constructed of a permeable material. This would permit any moisture-
laden air that may have entered the wall cavity through a discontinuity 
in the exterior vapor retarder to be dissipated through the interior 
permeable material. In such cases, use of vapor retarder paints, vinyl-
covered gypsum wallboard, or other impermeable materials or finishes on 
the interior side of exterior walls could be detrimental, because they 
would trap moisture within the wall.

II. This Waiver

    To address these concerns, HUD is issuing a waiver that applies to 
the first of the alternatives available under Sec. 3280.504(b), the 
current condensation control and vapor barrier installation 
requirements for exterior walls in humid and fringe climates. 
Specifically, this waiver allows manufacturers of homes for humid and 
fringe climates to install the vapor retarder on the exterior side, 
rather than the interior or living space side, of the exterior wall, 
provided: (1) The exterior side of the exterior wall is constructed 
with a vapor retarder or exterior covering and sheathing that has a 
permeance not greater than 1.0 perm; and (2) the interior finish and 
interior wall panels are designed with a 5 perm or higher rating. The 
waiver also requires manufacturers to add a statement and a map to the 
data plate indicating that the home is only suitable for installation 
in humid and fringe climates (the map designates the acceptable 
locations for which the waiver is applicable).

III. The National Fire Protection Association (NFPA) 
Recommendations

    Previously, HUD designated NFPA as the organization to undertake a 
voluntary consensus process to assist the Department in developing 
recommendations for new manufactured housing standards. Participants in 
the NFPA process met in December 1999 to discuss comments received on 
recommended standards changes. One such recommendation involved changes 
to HUD's regulation in Sec. 3280.504(b)(1) for homes sited in ``humid 
climates'' or ``fringe climates'' as set forth in figure 16, in Chapter 
21 of the 1989 American Society of Heating, Refrigerating, and Air-
Conditioning Engineers (ASHRAE) Handbook of Fundamentals. (The Humid 
and Fringe Climate Map being utilized in this waiver is based on 
ASHRAE's figure 16.) HUD received the preliminary results of the 
consensus process deliberations, and the NFPA recommendations have been 
considered in preparing this final waiver.
    The Department expects that recommendations received from the NFPA, 
research, field data obtained from the use of this waiver, and other 
information will be available for considering whether to effectuate 
changes to the standards of a more permanent nature. Any such change 
would first be reviewed by the Department and the new consensus 
committee to be established pursuant to section 604 of the Manufactured 
Housing Improvement Act of 2000(Pub. L.106-569, 114 Stat. 2944, 
approved December 27, 2000). A proposed rule would then be published 
for public comment.

IV. Analysis of Public Comments and Other Information Received

    The public comments received in response to the proposed waiver 
ranged from support for the proposal, to suggestions for revising the 
proposal, to out-right rejection of its provisions. In

[[Page 20401]]

general, those who did not favor the proposal indicated that the waiver 
did not go far enough since it did not address the larger issues of air 
leakage and transport of moisture-laden or humid air into exterior wall 
cavities. Two commenters, referencing or quoting the 1993 ASHRAE 
Handbook of Fundamentals, suggested that while the amount of water 
deposited in wall or roof spaces by air currents or pressure diffusion 
cannot be calculated with certainty, under some conditions that amount 
of water can result in several times the amount of moisture that would 
be caused by other means, such as vapor diffusion.
    While the Department agrees with the concerns raised in the 
comments, it also believes the waiver provides a partial solution for 
reducing the extent and number of moisture problems being experienced 
in Southern climates. Manufacturers who chose to take advantage of the 
waiver are reminded that it does not consider the larger transport of 
moisture by air leakage, and that their designs and construction in 
hot-humid climates also need to address those concerns. Among the 
strategies manufacturers should consider are: use of exterior air 
barriers; prevention of air leakage from supply duct systems and other 
penetrations causing negative pressurization of the home; avoiding use 
of oversized cooling equipment; and use of balanced mechanical 
ventilation systems. Complying with the provisions of the waiver does 
not relieve manufacturers of their responsibilities to use construction 
methods that result in ``durable, livable, and safe housing'' as 
required by 24 CFR 3280.303(b) of the Standards.
    Several commenters agreed that an effectively located, good quality 
vapor retarder could eliminate condensation caused by vapor diffusion 
(differences in vapor pressure). However, the waiver also requires the 
interior wall surface to be permeable so that any moisture that does 
become deposited within the space is not trapped by having an 
impermeable surface, such as vinyl-covered gypsum panels, on the living 
space side of the wall.
    The NFPA and another commenter recommended that a combined 5-perm 
rating be used instead of the 3 perm rating suggested in the proposed 
waiver. HUD agreed with this recommendation since there was no 
technical basis to support the lower perm rating in recognized 
engineering manuals, and the final waiver has been revised to require 
interior finish and wall panel materials to have a combined vapor 
permeance greater than 5.0 perms. Also, the Manufactured Housing 
Institute (MHI) collaborated with the Manufactured Home Research 
Alliance (MHRA) to test commonly used generic interior finish and wall 
panel designs to determine if they complied with the combined interior 
perm rating criteria in the proposed waiver. The results of the testing 
indicate that compliance with the higher perm rating would easily be 
achieved. Further, based on the Department's review of the MHI test 
results (submitted to amend MHI's original comments), the Department 
will not require testing of gypsum panels (textured or non-textured) 
that are finished or laminated with acrylic or latex paint or non-vinyl 
decorative wall paper to demonstrate the panels comply with the 5-perm 
minimum rating; these combinations of interior finish will be deemed to 
provide an acceptable level of performance.
    One State Agency expressed concern about enforcing different 
provisions for condensation control for the limited geographic area of 
the State subject to the Waiver. Two commenters were concerned about 
potential hardships in relocating homes built under the waiver to cold 
climate areas for which the homes were not suited. However, those 
concerns are no different than for other geographic-based requirements 
in the Standards, such as those for thermal, wind, or roof-load 
protection. Therefore, the Department has not made any changes based on 
these comments.
    Some commenters also suggested there is authority under the current 
Standards to permit the vapor retarder to be located on the exterior 
side of the wall. These commenters assert the 1989 ASHRAE Handbook of 
Fundamentals recognizes this practice and is incorporated by reference 
into the Standards. The Department does not agree that all provisions 
of the 1989 ASHRAE have been incorporated by reference, but to the 
extent they have been incorporated, the requirements of the Standards 
govern whenever the provisions of the 1989 ASHRAE Handbook are 
inconsistent with the requirements of the Standards. In addition, 
Interpretative Bulletin F-1-76 is not appropriate for these 
circumstances as it was intended to clarify requirements for cold 
climates, where vapor diffusion would occur from the interior to the 
exterior of the home and not vice-versa. As such, IB F-1-76 is 
applicable to the requirements in Sec. 3280.504(b)(2), rather than 
Sec. 3280.504(b)(1), the provision to which this waiver is applicable.
    The Department did not accept a further recommendation of MHI and 
another commenter to exempt certain construction (kitchen back splash 
materials, bathroom tub and shower compartments, cabinetry and built-in 
furniture, and hardwood plywood paneling under chair rail areas) from 
the combined interior perm requirement, because the Department does not 
have technical data to support their proposal.
    The Department also did not accept the commenters' recommendation 
to combine and simplify the ``humid'' and ``fringe'' designations on 
the map into one area, as both the ASHRAE Handbook of Fundamentals and 
the NFPA 501 Standard on Manufactured Housing refer to them as two 
distinct areas in their maps.
    In view of all of the above, HUD is issuing this final waiver, but 
reminds manufacturers that additional measures are likely needed in the 
design and construction of their homes to sufficiently abate the 
moisture problems in hot, humid climates and, therefore, comply with 
other requirements in the Standards.

V. Alternative Methods

    This waiver is not intended to limit alternate approaches by 
manufactured home producers in assuring that homes built and sited in 
humid and fringe climates are durable and free of moisture-related 
problems. Other methods of moisture control that do not meet the 
Standards or the conditions of this waiver may be submitted for review 
and consideration in accordance with 24 CFR 3282.14 (entitled 
``Alternate Construction of Manufactured Homes'').

VI. Final Waiver

    In accordance with 24 CFR 3280.8 and 42 U.S.C. 3535(q), the 
Secretary hereby waives, subject to certain conditions, the specific 
requirements of 24 CFR 3280.504(b)(1) for homes to be sited in humid or 
fringe climate areas as identified in section V.F of this waiver. 
Manufacturers who elect to utilize the alternative permitted under this 
waiver, rather than to follow the existing requirements in 24 CFR 
3280.504(b)(1), must produce homes in accordance with the following 
requirements (all other requirements of the Standards also continue to 
apply):
    A. Exterior walls must be constructed with one of the following 
installed on the exterior side of the wall assembly: (1) A vapor 
retarder of not greater than 1.0 perm when measured and tested in 
accordance with ASTM E-96-93, Standard Test Methods for Water Vapor 
Transmission of Materials (dry cup method); or (2) an external covering 
and sheathing with a combined permeance of not greater than 1.0 perm.
    B. The interior finish and interior wall panel materials must have 
a combined

[[Page 20402]]

vapor permeance greater than 5.0 perm (dry cup method). Gypsum wall 
panels (textured or non-textured) that are finished or laminated with 
acrylic or latex paint or non-vinyl decorative wallpaper need not be 
tested to establish their compliance with the 5.0 perm combined vapor 
permeance requirement. Other interior finish and wall panel materials, 
such as vapor retarder paint, vinyl-covered gypsum wall panels, and 
other impermeable interior surfaces and finishes, must be demonstrated 
to have a combined rating greater than 5.0 perm (dry cup method) or 
they are prohibited.
    C. Exterior wall cavities shall not be ventilated to the outdoors.
    D. An additional statement shall be provided on the data plate 
required by 24 CFR 3280.5, to read as follows: ``As designed and 
constructed, this home is suitable for installation only in humid and 
fringe climates as shown on the Humid and Fringe Climate Map provided 
with this data plate.'' The statement is to be typed in bold face using 
letters at least \1/4\ inch in size.
    E. A reproduction of the following Humid and Fringe Climate Map is 
to be provided on the data plate. The map shall not be less than 3\1/2\ 
in. by 2\1/4\ in. in size.
[GRAPHIC] [TIFF OMITTED] TR24AP02.021

    F. 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, and this waiver may be applied to homes built to be sited 
within these jurisdictions:

Alabama

    Baldwin, Barbour, Bullock, Butler, Chootaw, Clarke, Cofee, 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

Louisiana

    All counties and locations within the State of Louisiana.

Mississippi

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

[[Page 20403]]

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, Gavelston, 
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 Augistine, 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

    Dated: April 16, 2002.
John C. Weicher,
Assistant Secretary for Housing-Federal Housing Commissioner.
[FR Doc. 02-9860 Filed 4-23-02; 8:45 am]
BILLING CODE 4210-27-P