- Oct 28, 1999
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Including under the slab? If not, do it.
I think my contractor has 3/4" foam spec'ed out under the basement slab. We're doing radiant heating in the basment and the tubes will go over that. My builder is a big time energy saving geek. Our house will be tested and (hopefully) energy star certified when it's done. Along with the insulating properties, I guess the foam also really helps keep down radon. We're in a very high radon area. His houses with the foam all around the foundation and under the slab have the lowest radon readings he's ever seen.