insulation under slab for garage
Looking to insulate under a slab for a garage in NW PA (zone 6 I think). Plan is to install pex for radiant heating the slab, and the slab is to be 5″ thick. Temp will likely be set to heat around 60F. What R value is recommended/required, and what type of insulation is recommended. I know EPS seems more economical than XPS, but not sure about that, or much else. I’ve had sellers tell me polyiso is better, but I’m pretty sure that’s wrong (moisture wicking?). Is 10 psi adequate, or to “brittle” or compressive for installation? I had someone tell me use 25 psi around perimeter, and 10 psi everywhere else? Can’t seem to find any reclaimed stuff near me. Any input is appreciated. Thanks all.
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