How to Insulate Slab Houses

Building a house directly on a concrete slab is a money-saving option for home construction. This type of home construction requires different insulating specifications than a home built with a traditional basement.

Instructions

1. Insulate the concrete slab. Install rigid foam board insulation on top of a vapor barrier which is placed on top of an aggregate gravel base. The concrete slab is then poured on top of the insulation.

2. Install 1-inch by 2-inch furring strips on the concrete floor. Insulate between the furring strips with rigid foam board insulation. Install a wood subfloor on the furring strips. Hardwood flooring, carpeting or tile can then be installed over the subflooring.

3. Insulate the foundation with rigid foam board insulation designed to insulate foundation walls. The panels have a recess along their edges which holds a 1/2-inch by 4-inch furring strip when two panels are placed side by side. Fasten these to the foundation with masonry screws inserted through the furring strips and the insulation.

4. Insulate the exterior walls using traditional fiberglass batt insulation prior to installing the interior sheetrock. Install the fiberglass insulation between the studs on the exterior walls.

Tips & Warnings

• A vapor barrier is not needed when installing rigid foam board insulation to insulate concrete slab floors above ground or against foundation walls.

References

• Insulate slab houses