Need Advice on Insulation for Floor Above Crawlspace and Above Garage
So for the expansion off the existing house, there will be a non-ventilated, but insulated (with R-21 Insulation) crawlspace that will have a 6 mil polyethelene vapor barrier along the wall and floor. Any seams in the polyethelene will be sealed with caulk and/or liquid nails (still trying to figure out which holds up the longest). The polythene will be covered by stone.
So the question is, should I also insulate in between the floor joists of the 1st Floor? Or is the R-21 insulation in the crawlspace walls sufficient? Please note the Crawlspace walls are of a PWF design, so the insulation will it in between the 2×6 stud cavities with polyethelene on the inside and outside of the walls.
As for the space above the unheated but insulated garage with concrete floor, for the heated 2nd floor, should I install insulation in between the joists of the 2nd floor in that space? Or am I wasting money on insulation.