Concrete is not a good insulator. I would like to use foam insulation for the ceiling spaces (especially under the roof). Most of the contractors I speak to use fiberglass batting. It’s cheaper than foam insulation but not as effective. Does anyone in the Keys install foam insulation at an affordable price? Foam insulation has an R value of 1″ = R-6.8, NCFI – rigid insulation spray, 3-1/2” = R21. Between the outside walls and the wall of a room…