Mobile home vapor barrier replacement
The plastic on the ground under your home keeps Florida's ground moisture out of the belly, the insulation and the floor. When it's torn or missing, we replace it.
What the vapor barrier does
Under most mobile homes there's a sheet of plastic covering the dirt. It keeps moisture in the ground from rising into the crawl space, where it soaks the belly insulation, rusts the frame and straps, and works its way up into the floor. In Central Florida, with wet summers and heavy humidity, that ground moisture never really lets up.
The federal installation standards for manufactured homes require it on any skirted home: the whole ground area under the home covered with a vapor retarder of at least 6 mil polyethylene, seams overlapped at least 12 inches, and any voids or tears repaired, unless the home is in an arid region with dry soil (24 CFR 3285.204).
Signs yours needs replacing
- Plastic that's torn, bunched up or missing in sections
- Bare dirt showing around piers and anchors
- Standing water or damp soil under the home after rain
- A musty smell inside, especially near the floor
- Wet or sagging belly insulation
- Condensation or rust on the frame, straps or ducts
How we replace it
Look first
We go under the home, check where water collects and look at the belly, piers and straps while we're there.
Clear it out
Old torn plastic and debris come out so the new sheet lies flat on the ground.
Cover all of it
New polyethylene goes down over the whole area under the home, seams overlapped, fitted around piers and anchors.
Tell you what we saw
If the belly is torn or the home is out of level, you hear about it with a price, not a surprise.
Often done together
A soaked crawl space usually means the belly above it has taken a beating too. Because we're already under the home, it makes sense to check the underbelly and the piers and level in the same visit.
Questions about vapor barriers
Is a vapor barrier required under a mobile home?
Under the federal installation standards, yes when the home is skirted: the ground under it has to be covered with a vapor retarder unless the home sits in an arid region with dry soil. Florida is anything but arid.
How thick should the plastic be?
The federal standard calls for at least 6 mil polyethylene sheeting or its equivalent, with joints overlapped at least 12 inches.
Is the vapor barrier the same as the underbelly?
No, although people use the words for both. The vapor barrier is plastic laid on the ground. The underbelly, or belly wrap, is the material stretched across the bottom of the floor. If the belly is the problem, see underbelly repair.
Do I need a new one if mine just has a few tears?
Not always. The standard says voids and tears have to be repaired, and small ones can be patched. When the plastic is shredded, missing in places or buried in debris, replacing it is the cleaner fix.
Torn plastic or a damp crawl space?
Call or text Adam and tell us what you're seeing under the home. We'll come take a look, and the estimate is free.