Insulating the underbelly: Paper back or not?

Repair help for the do-it-yourselfer.
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Posts: 11
Joined: Sat Sep 22, 2012 12:05 pm

Sat Oct 06, 2012 1:06 pm

Im in the process of removing the old underbelly material and insulation. when i talk to mobile home repair stores or contractors they all recommend not using the insulation that has a paper backing on it. their reasons are mostly moisture related. I purchased the repair manual on this site and was reading the authors process of repairing the underbelly and he mentions using a paper backed insulation (pg 1-4). So whats the deal, can I or should I not use the paper back insulation? seems like a lot of "experts" have opinions but i cant seem to get a straight answer as to what to use. Any thoughts and help is appreciated.


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Sat Oct 06, 2012 3:19 pm

Hi Will,
I think this may be a real concern for homes in cold and/or humid climates. The whole thinking is that your underbelly is the defacto moisture barrier and the paper backing would be a second moisture barrier. Water vapors or a plumbing leak could create moisture between the two barriers possibly leading to a mold/mildew problem. Within an intact underbelly, unfaced insulation would offer the same R value as faced, so going with unfaced insulation (or simply removing the paper facing) would be your safe bet.

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