Roxul for crawlspace stemwall? And a related detail.
Basic question: Is Roxul Comfortboard a suitable substitute for the usual interior rigid foam insulation in retrofitting a crawlspace? (House in zone 5, crawlspace floor is about a foot below outside grade, walls are CMU. drainage is very good. I do plan to use cut’n’cobble XPS in the rim joist area, to ensure good air seal. Homeowner very opposed to foam if it’s not necessary, which has led me to look into Roxul.)
Related: Martin’s article on conditioning crawlspaces (https://www.greenbuildingadvisor.com/blogs/dept/musings/building-unvented-crawl-space) recommends running the floor membrane clear up the wall to within 3″ of the top of foundation, and THEN installing insulation over that. Conversely, the drawings in the “Strategies and Details ” section show the membrane ending at the base of the wall. How does this detail affect the facing (if any) on the insulation?
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