Rigid Foam Insulation Under Subfloor

Or as demonstrated here you can cover the slab with rigid foam insulation add two layers of plywood and then add the finish flooring.
Rigid foam insulation under subfloor. Foam board insulation is used on attics and walls yet it can also be used to insulate your floors. 2x4 sleepers installed on center every 12 16 inches and fastened down with rigid foam insulation 1 1 2 inch thick placed between the sleepers. The foam butts against the mudsills for a complete thermal break. Most people do not think about insulating their floors unless perhaps it s their attic floor.
The polyethylene sheet becomes part of a continuous air barrier for the home. Insulate the band joist with batt insulation as well as the crawlspace access if it s located in the wall. 6 install rigid foam board or batt insulation exterior foam interior foam or interior batt to achieve complete insulation coverage. But insulating your floors is a good idea for many reasons including energy efficiency and height adjustments.
Concrete basement floor. You want it snug but not to. You can attach wood sleepers to the floor fill the gaps with rigid foam insulation and then apply your finish flooring. The top layer of subfloor steps back and gets a layer of peel and stick flashing tape to form pan flashing under the sliding doors.