Crawl Insulation

I have been planning to insulate perimeter foundation walls in crawl with about 1’’ spray foam from sill to bottom of walls. This is in conjunction with concrete encapsulation and supply/return air for complete conditioning of crawl space. I just read where spray foam insulation on walls is not good because it will not allow walls to breath, therefore trapping moisture. I’ve heard more positive benefits than negative. Anyone know about this?


On our current remodel we had a company come in for estimates on spray foam for the entire house, which included the crawlspace. As explained to me, as long as open cell foam is used it will be fine. Just as open cell should be used for spraying the underside of sheathing/rafters in an attic. Open cell allows moisture (if any is present) to “bleed” through.

Thanks Brian. :smile: