Will rigid insulation above fiberglass prevent condensation in a vented crawl space?
Hello Fellow Building Aficionados!
The building I am working on has a vented crawl space with a dirt floor (same grade as exterior) and lives in the hot humid land of Oklahoma City. (Climate Zone 3)
My goal is to meet the code required floor insulation value of R19 with the least amount of skill and cost possible while still getting the job done right. Here are my two questions:
– In a humid climate like OKC, will fiberglass insulation work to insulate a floor system or is the risk of mold and condensation too high?
– Would it be possible to use a layer of rigid foam to keep the crawl space warm enough during the summer to prevent condensation/mold in a layer of fiberglass? The system from top to bottom would be subfloor, R5 rigid insulation sealed with foam, R13 unfaced fiberglass batts & insulation supports, and a 10mil poly vapor barrier on the floor of the crawlspace.
My thinking is that this would work the same way that walls with exterior foam work in northern climates by preventing the wall sheathing from getting cold enough to have condensation problems?
I work with a non-profit construction company that uses volunteer labor and donations, so I often need to get creative to get my projects done well with the resources I have.
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