I have a raised house in a hot humid climate, with a concrete slab under the crawl space (6 mil. poly laid under the slab), 3/4" plywood subfloor, 15 lb. felt paper and 3/4" tongue and groove antique pine flooring. There is no insulation under the subfloor. Pine flooring is beginning to buckle. Moisture content of pine is 15% and subfloor in the high 20's. Is there any way to stop moisture drive through subfloor?
Should I insulate and/or install some sort of vapor barrier under subfloor?