Most of Florida has plenty of rainfall, especially during the summer months, plus high humidity, so moisture in the soil evaporates continuously from the ground under a mobile home. During periods of high rainfall or after a severe thunderstorm you can expect the soil to damp for several days.This is not a problem as long as there is enough ventilation to allow it to dissipate into the open air around the home.  

    But if the ground is continuously damp with high humidity, or wet, something is wrong. There are several possible reasons why:

1) It could be caused by water flowing under the home due to poor site drainage, like in the photo below. 

The ground around the home should be graded so that water runs around it instead of under it. This is usually done by creating a raised pad under the home and sloping the ground away from the it on all sides. 

2) If there are not enough ventilation openings in the skirting, or they are not distributed around all sides, humidity can build up. It is especially important to have ventilation near the corners.

3) Any plumbing pipe leakage under the home is another cause. Also, the water heater TPR valve (it opens to release pressure if the water heater overheats) has piping that may terminate under the home. The valve sometimes leaks and causes a continuous drip into the crawl space. 

    New mobile home installations since November, 2008, have been required to have a ground cover vapor barrier (plastic sheeting) covering the entire crawl space, and this has proved effective in reducing moisture buildup under the home. See our blog post Is a ground cover vapor barrier (plastic sheet) required under a new mobile/manufactured home? for more on this.

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manufactured/mobile homes? 
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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?

• 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? 

• Is it safe to go under a mobile 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? 

• How do I find out how old a mobile home is and who manufactured it?

• What is the right price for a used mobile home?

• How energy efficient is a mobile home?

• When were the first double-wide mobile homes manufactured?

• How do I upgrade my old (pre-1976) mobile home to meet HUD standards?

• How do I find out if a manufactured/mobile home has been moved from its original location? 

• 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? 

       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.