Manufactured home under floor membrane

Inspected a “double wide” today. The “membrane” below the floor in the crawl space that covers the ducting and insulation was open. Some cut away and hanging and some just torn. What’s the membrane called, purpose, and should it be resealed/taped, major issue. Thanks

The industry refers to it as a “belly wrap.” If it is of a solid plastic material, it is most likely the underneath vapor barrier. If it’s of a thin mesh, just a wrap that helps support any insulation. Either way, it should be noted and yes, re-taped and sealed.

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what Tom said…it also helps keep critters out…

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Great Thanks!

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That’s a good place to find possums, racoons and skunks!

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Found there and the skunks are the worse.

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download (1)

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are You really looking for possums coons and skunks…that is a strange hobby…just sayin…

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Not sure about you Jim, but anytime I go under a home, I keep one eye out looking for vermin, spiders and snakes…

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Most of the time the under belly wrap is a house wrap type of material…so it holds up the insulation without stopping all moisture flow. I have seem some with a plastic type of material but I think that is a mistake. At any rate if there’s a hole or torn place it compromises the whole thing…so any tears should be patched.

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And when you inspect one, look for sags as they may indicate water is pooling there…push up on it and you will hear the water…which is not good.

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LOL… just poke a hole in it so the water will drain out…what fun…

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That is called either the “belllyboard” or “bottom board”. It primarily holds up the insulation and rodent-proofs the home. It should always be taped and sealed. Many times people do work under the home and never re-seal the bellyboard. Also, Realtors will ALWAYS refer to the bellyboard as the vapor barrier. I always have to school them that the vapor barrier lays on the ground…not stapled to the undercarriage.

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Vapor barriers can and often are installed in several areas of a home. One of those locations is of course the crawlspace dirt floor. Belly wraps (boards) are typically moisture barriers, not vapor barriers because trapping moisture would likely cause a problem.

From the article:

A vapor barrier is intended to keep water vapor or water molecules from passing through the barrier. Water vapor is a gas or “vapor”.

Plastic or polyethylene is a vapor barrier. The plastic sometimes used on the warm-side of building walls (on the wall interior under drywall in northern climates) is a vapor barrier. Vapor barriers are both waterproof and vapor-proof.
https://inspectapedia.com/BestPractices/Sheathing_Wrap_Requirements.php

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This is very common with manufactured homes and can occur during the original setup, some type of previous repairs, pest concern, or even some type of damage. Sometimes it can be very difficult to determine what caused the damage, do to accessibility or visibility. Also there are different types of material used for the belly side moisture barrier.

Here is the verbiage I use.

“The moisture barrier and insulation on the belly side of the sub flooring in crawlspace was missing and or damaged in some areas. The purpose of the moisture barrier is to provide a level of protection to the floor system from moisture or dampness. Recommend further evaluation from a qualified licensed contractor and any corrective repair that may be necessary.”

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