Insulate Basement Floor With Rigid Foam

To attach the insulation you can use screws with large washers a special adhesive made for adhering foam board insulation or for smaller pieces you can seal them in with caulk or spray foam.

Insulate basement floor with rigid foam.

If your basement slab lacks sub slab foam you ll have to install the insulation above the slab. You can use either one or two layers of plywood or osb and the subflooring can either be fastened to the concrete with long tapcon screws or it can simply float above the foam. Rigid foam is combustible so by code must be sealed in by a thermal barrier of either drywall or 5 5 of roxul with the latter providing added insulation in a critical heat loss zone provide sound dampening to the above floor. If the basement floor is wet hire a professional find the source of the problem and fix it before doing anything.

Step 5 cover with plywood. Place your rigid foam insulation between the sleepers in the open areas. For new construction use rigid boards to insulate slabs and the outside of foundation walls. It gets rid of any air movement behind the walls.

Step 4 install the insulation. 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. Once the insulation has been placed you will want to cover it up with plywood. After the rigid foam is on the floor and walls it can be studded over.

You may need to cut the insulation down with a utility knife to make sure it fits properly between each grid. Except for the deep south. Concrete basement floor. Attach the tongue and groove insulation boards to the concrete wall with adhesive.

Insulating the basement this way creates a thermal break between the air inside your basement and the air outside. If the concrete floor is dry and reasonably level insulate directly on top with a rigid foam insulation that is impervious to moisture air leakage and radon gas. It s like a beer cooler which has rigid foam insulation too. The best insulation to use is rigid foam which is largely unaffected by moisture.

Use a premade kit for this type of project. Energy savings are about the same whether you insulate on the interior or exterior. There are several ways to install subflooring above the rigid foam. I posted on the basement insulation site but i ve developed my thinking a little more and now ponder whether this would work for the concrete basement floor that i very much want to finish in ceramic tile 6 poly 1 xps foam 3 4 advantech 1 2 hardibacker thinset and 1 4 tile.