Hi, new member here. I am renovating a 25’x20’ guesthouse in a wooded area next to a pond in Wisconsin. So it is a damp climate that ranges maybe from -20 to 110 degrees at the extremes. The floor of the cabin is 10” joists over a 2’ crawl space of dirt. I encapsulated the crawl space the best I could with a heavy plastic vapor barrier, then layed pressure treated plywood across the bottom of the joists to act as a support for foam and had 4” of closed-cell foam sprayed between the joists. My plan was to lay 1/2” pex on top of the spray foam between the joists, then put the subfloor down. My knee jerk thought was to put a reflective foil down between the foam and the pex, but I started to think that there could be risk of condensation between the foil and foam if there is a significant heat gradient. A friend also mentioned the thought of pouring concrete in to act as thermal mass, but that might be a separate question. Thoughts? Thanks people!