Insulating a Concrete Foundation Wall
I am soon to be building a garage in Wisconsin (Climate Zone 6b). The framing will sit on 4’ frost walls with a 6” slab on the inside. I will be running a radiant heat system in the entire building (37’ x 66’). I am looking for guidance as I choose how to insulate the foundation and slab most efficiently. Here is what I am thinking:
Foundation: 2” of eps on the outside of the foundation wall
Slab: 2 layers of 2” eps (4” total) under slab
I am also considering using either 1” or 2” eps on the outside of all the exterior walls. The exterior walls will be blown in fiberglass along with the attic.
My main question is weather or not I should have the foundation insulation layer on the inside or the outside of the 8” concrete foundation wall? Also is 4” of insulation overkill under the slab?
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