Insulated floor on top of concrete slab
I am considering building a slab-on-grade, or slab with short perimeter footers, superinsulated house in a cold climate. Most slab insulation schemes I’ve seen put foam insulation under the slab, often with fancy insulation schemes at the slab edge. I very much dislike having a hard, cold concrete floor (and, yes, even a 60*F concrete floor is cold to bare feet). Is there a simple cheap way to make an un-insulated slab with all the insulation placed on top of the slab, then a plywood sub-floor placed on top of the foam? Or maybe 1×6 “floor joists” set directly on the concrete, with insulation (foam, fiberglass, cellulose?) between the joist? Any other ideas?
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