Things You'll Need

Instructions

1

Line your home's foundation floor with a vapor barrier made out of 10 mil polyethylene. Place a layer of heavy felt building paper on top of the vapor barrier to protect it.
2

Measure 2 feet in from the foundation walls around the perimeter of the floor and place 3-inch foam boards along that perimeter. Measure 4 feet in from the foundation walls and place 4-inch foam boards along that perimeter. Insulate the rest of the foundation floor with 2-inch foam boards.
3

Install 2 inches of foam insulation around the perimeter of the foundation wall. Measure 4 feet down from the ground-line and install 3-inch foam boards. Measure 2 feet down from the top ground level, and place 4-inch foam boards around the perimeter. In other words, increase the insulation's thickness to 3 inches when it reaches 4 feet from the ground's surface, and 4 inches when it reaches 2 feet from ground level.