Rigid Foam Insulation Under Subfloor

In other words rigid foam can be applied on walls foundations and roofs and works great for both retrofits and new constructions.

Rigid foam insulation under subfloor.

Concrete basement floor. Foam board insulation is used on attics and walls yet it can also be used to insulate your floors. 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. Insulate the band joist with batt insulation as well as the crawlspace access if it s located in the wall.

There are two ways to handle insulating concrete floors. But insulating your floors is a good idea for many reasons including energy efficiency and height adjustments. 6 install rigid foam board or batt insulation exterior foam interior foam or interior batt to achieve complete insulation coverage. You can attach wood sleepers to the floor fill the gaps with rigid foam insulation and then apply your finish flooring.

Or as demonstrated here you can cover the slab with rigid foam insulation add two layers of plywood and then add the finish flooring. 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. You want it snug but not to.