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Proposed Rule

Manufactured Home Construction and Safety Standards; Condensation Control for Exterior Walls of Manufactured Homes Sited in Humid and Fringe Climates; Notice of Proposed Regulatory Waiver

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Office of the Assistant Secretary for Housing—Federal Housing Commissioner, HUD.


Proposal of waiver; request for comments.


This notice advises the public of HUD's proposal to issue a waiver of its regulations regarding manufactured home construction and safety standards. HUD may issue a final regulatory waiver after reviewing the public comments received in response to this notice. HUD proposes to waive certain provisions of these regulations when manufacturers, at their option, 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. The states have provided HUD with information that indicates there is an immediate need to consider alternate requirements for exterior walls in these humid and fringe climate areas, to prevent moisture damage due to condensation. HUD intends for this waiver to be in place for no more than 24 months, as permanent changes to the regulations are being considered.


Comment due date: May 1, 2000.


Interested persons are invited to submit comments regarding this notice to the Regulations Division, Office of General Counsel, Room 10276, Department of Housing and Urban Development, 451 Seventh Street, SW, Washington, DC 20410-0500. Communications should refer to the above docket number and title. Facsimile (FAX) comments are not acceptable. A copy of each communication submitted will be available for public inspection and copying between 7:30 a.m. and 5:30 p.m. weekdays at the above address.

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Rebecca J. Holtz, Acting Director, Office of Consumer and Regulatory Affairs, Room 9146, Department of Housing and Urban Development, 451 Seventh Street SW, Washington, DC 20410-8000; telephone (202) 708-0502 (this is not a toll-free telephone number). Hearing or speech-impaired individuals may access this telephone number via TTY by calling the toll-free Federal Information Relay Service at 1-800-877-8339.

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I. Background

Manufacturers and State Administrative Agencies (SAAs) in southeastern States have recently reported an 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, the Standards at 24 CFR 3280.504 do not distinguish between climates for requirements for condensation control and installation of vapor retarders. 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 would be detrimental, because they would trap moisture within the wall.

II. This Notice

To address these concerns, HUD is considering issuing a waiver to the current condensation control and vapor barrier installation requirements for exterior walls in humid and fringe climates. Specifically, this waiver would allow for manufacturers, in humid and fringe climates, to install the vapor retarder on the exterior rather than interior or living space side of the exterior wall. The proposed waiver will permit manufacturers to locate the vapor retarder on the exterior side of the wall assembly provided there is no vapor retarder on the interior and the interior finish or interior wall panels are designed with a three perms or higher rating. The waiver will also require 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 and provide a map to designate the acceptable locations.

The Department intends for the final waiver to be effective for a period not to exceed 24 months. This will permit the Department to consider recommendations received from the National Fire Protection Association (NFPA), research, field data obtained from the use of this waiver, and other information to effectuate changes to the standards of a more permanent nature.

III. NFPA Consensus Standards Process

HUD has designated the NFPA to undertake a consensus process 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 that was discussed involved changes to HUD's regulation at 24 CFR 3280.504(b)(1) for homes sited in “humid climates” or “fringe climates” as set forth in figure 16, Chapter 21, 1989 ASHRAE Handbook of Fundamentals. (The Humid and Fringe Climate Map being proposed in this waiver is based on figure 16 in ASHRAE.) HUD looks forward to receiving the results of the consensus process and does not intend for this proposed waiver to undermine a consensus approach to standards revisions on this matter.

IV. Alternative Methods

This proposed waiver is not intended to limit alternate approaches by manufactured home producers in utilizing other solutions to assure that homes built and sited in warm humid and fringe climates are durable and free of moisture related problems. Other methods of moisture control that meet the intent of the 24 CFR part 3280 and this proposed waiver may be submitted for review and consideration in accordance with 24 CFR 3282.14 Start Printed Page 17111(entitled “Alternate Construction of Manufactured Homes”).

V. Comments Requested

Comments are specifically requested on the Department's decision to proceed with a waiver in warm humid and fringe climates to permit the vapor retarder to be located on the warm side of exterior walls.

VI. Proposed Waiver

In accordance with 24 CFR 3280.8, the Secretary hereby proposes to waive the specific requirements of 24 CFR 3280.504(b)(1) for homes to be sited in a humid or fringe climate as identified in section VI.F. of this waiver. Manufacturers who elect to utilize this alternative rather than to follow the requirements of the existing standards in 24 CFR 3280.504(b)(1), must produce homes in accordance with the following requirements (all other requirements of the Standards continue to apply):

A. Exterior walls must be constructed with a vapor retarder of not greater than 1.0 perm (dry cup method) or an exterior finish and sheathing with a combined permeance of not greater than 1.0 perm installed on the exterior (warm side) of the wall assembly.

B. The interior finish and interior wall panel materials shall be designed to have a combined vapor permeance greater than 3.0 perms (dry cup method). Vapor retarder paint, vinyl covered gypsum wall panels, and other impermeable interior surfaces or finishes that have a combined rating less than 3.0 perms (dry cup method) shall be 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 that indicates: “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.

F. The following areas of local governments (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 would apply to homes built to be sited within these jurisdictions:


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


All counties and locations within the State of Florida.


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, GlynnWayne, Grady, Irwin, Jeff Davis, Lanier, Lee, Liberty, Long, Lowndes, McIntosh, Miller, Mitchell, Pierce, Quitman, Start Printed Page 17112Randolph, Seminole, Tattnall, Terrell, Thomas, Tift, Turner, Ware, Worth.


All counties and locations within the State of Louisiana.


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.

North Carolina

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

South Carolina

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


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.

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Dated: March 23, 2000.

William C. Apgar,

Assistant Secretary for Housing-Federal Housing Commissioner.

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[FR Doc. 00-7782 Filed 3-29-00; 8:45 am]