how to insulate hydronic heated floor over a crawlspace
I live in southern Maine, Zone 5. My kitchen floor is about 250 sq ft and is over a crawl space about 2′ – 3′ high. The stone walls around the crawl space has been sprayed foamed. I have laid a 1/2″ tube hydronic radiant floor over the subfloor in a slab about 1.5″ thick. Right now the i am pumping water into the loop at about 81deg and the return is coming out about 71deg. the slab temp is only about 61degs. this has been running for over a week now. I did not insulate the underneath of the subfloor. I now believe i need to insulator under the sub floor. Here’s my questions.
Should I use a reflective foil against the subfloor than follow up with rigid insulation board? should I use a rigid insulation board with foil? will just one layer of 2″ rigid board be enough?
Prior to the pouring of the slab, I had batting underneath. but rodents would get in and tare it down. So i would like to prevent this.
Thanks for your comments
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