Crawlspace air sealing question
Hi. Our house is built on a slope w/ a walk-in basement. We have a breezeway over newer construction that created an ~5′ tall crawlspace of about 160 sf which we framed as a walk in shed. Ceiling joists are 2×10 and filled w/ R30 kraft-faced fiberglass.
This has a few drawbacks. The FG is easily disturbed given the activity that happens in the shed, insects and rodents have nested inside the FG, AND the breezeway tends to be cold in the winter due to lack of air sealing. As such I have been looking for ways to better air seal the space from below. I priced out CC foam but it is very expensive and hard to find a vendor who will do small lots, so have been thinking about “smart” membranes and plywood.
I have plenty of leftover Certainteed “Membrain” which is supposed to release moisture one-way. Would it be an acceptable solution to attach a layer of Membrain (pointed out), cover w/ a thin ply like luan or melamine board, and tape/caulk the seams? Just want to see if I can solve this at minimal cost and without inviting any new problems. Thanks as always!
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