How To Insulate A Floor Over A Crawl Space. If you have a closed crawl space, insulating between the joists is acceptable but we recommend insulating the. In this episode, larry janesky, own.

Seal seams between the boards with pvc tape. If the crawlspace will be accessed frequently for storage, choose rigid foam and a concrete slab. Cut rigid foam pieces to size with the saw and attach the pieces to the inside crawl space walls with the latex adhesive.