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Is a ground cover vapor barrier (plastic sheet) required under a new mobile/manufactured home?

Thursday, June 14, 2018

Yes, both the U.S. Department of Housing and Urban Development (HUD) and manufacturers’ installation manuals require a plastic sheet “vapor retarder material” on the ground under the home when the crawl space is enclosed by skirting or other materials.  “The HUD requirement has been in place since October 20th of 2008,” according to Vickie Ladd. of the Manufactured Housing Section of the Florida Department of Highway Safety and Motor Vehicles. An exception is allowed when the home is installed in an area with dry soil conditions, and is not required to be retrofitted on an existing home.

Joints Can Be Overlapped

     Joints in the material do not need to be sealed, as long as they are lapped at least 12-inches. The plastic sheeting can be placed beneath footing pads, over the pads, or around them, and must be fitted around any anchors or other obstructions.

    Here’s the exact wording of HUD’s “Part 3285 - Model Manufactured Home Installations Standards.” It is a national minimum requirement and local jurisdictions are allowed to set higher standards.

§3285.204   Ground moisture control.

(a) Vapor retarder. If the space under the home is to be enclosed with skirting or other materials, a vapor retarder must be installed to cover the ground under the home, unless the home is installed in an arid region with dry soil conditions.

(b) Vapor retarder material. A minimum of six mil polyethylene sheeting or its equivalent must be used.

(c) Proper installation. (1) The entire area under the home must be covered with the vapor retarder, as noted in §3285.204(a), except for areas under open porches, decks, and recessed entries. Joints in the vapor retarder must be overlapped at least 12 inches.

(2) The vapor retarder may be placed directly beneath footings, or otherwise installed around or over footings placed at grade, and around anchors or other obstructions.

(3) Any voids or tears in the vapor retarder must be repaired. At least one repair method must be provided in the manufacturer's installation instructions.

     The ground cover material must be a minimum of six-mil polyethylene sheeting (Visqueen® is a common brand), but no color requirement is specified. An alternative material may be allowed, if approved by local jurisdiction. The entire area under the home has to be covered, except at open porches, decks, and recessed entries. 

    Also, go to our HUD-CODE FOR MOBILE HOMES page for a listing of our other HUD-code articles.

Here’s links to a collection of our blog posts about MOBILE/MANUFACTURED HOMES:

Where can I file a complaint if I have problems with my new or used manufactured/mobile home in Florida?

 What are the most common defects in mobile/manufactured home foundation piers?

How do I determine the age of a very old mobile home?

• How can I tell if a mobile/manufactured home will pass a foundation certification inspection?

What is a "HUD label verification letter" for a mobile/manufactured home?  

When did a ground cover vapor barrier (plastic sheet) become required under a mobile/manufactured home? 

Are older mobile homes unsafe? 

What do I need to know about buying a foreclosed mobile home? 

Does it make sense to buy an older mobile home and remodel it? 

Where do I find the vehicle identification number (VIN) on a mobile home? 

What size air conditioner is right for my mobile home? 

Can you move an older mobile home in Florida? 

What does the HUD tag look like and where do I find it on a mobile home? 

Can you put a zone 1 mobile home in Florida?

How can I remove water under my mobile home?

What's the differences between a trailer, a mobile home, a manufactured home, and a modular home? 

What is a D-sticker mobile home? 

What are the tie-down requirements for a mobile home?

How fireproof is a mobile home?  

Can I install a mobile home myself?

What is a Park Model mobile home?  

Does an addition to a mobile home have to comply with the HUD Code? 

What walls can I remove in a mobile home?

What can I do to prevent dampness and mold in my mobile home? 

How can I tell if a mobile home is well constructed?

How can I tell the difference between a manufactured home and a modular home?

       Visit our MOBILE/MANUFACTURED HOMES  page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.

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