Can I Insulate the Floor of a Crawlspace With Rigid Foam Insulation?
The overhead floor of a crawlspace–usually the dwelling area of a home–can be insulated with rigid insulation. Often times, homeowners insulate their crawl space floors with batt insulation. The problem with batt insulation is that moisture can penetrate the paper backing and weaken the insulation, thus causing the insulation to sag or fall. Although rigid insulation will never provide the R value that batt insulation does, it will serve to keep interior and exterior climates from clashing. Rigid insulation–four by eight foot foam board that is a half to three-quarters inch thick–is waterproof, and, as the name states, rigid.
