I recently built a shop. It's 14x20 with 12' ceilings. It's built like My house with two by stick frame, tyvek, sheathing, siding, insulated, drywall. The structure sits on a foundation, and the floor is cement which sits on top of about 2' of compacted sand. There is no plastic barrier below the cement (wish I would have). I have a couple of issues. There is way too much moisture in the shop. I have been using a propane heater to heat while building and I realize they induce moisture. Would just switching to a normal heating of some kind get rid of My mositure? Sealing the concrete?