Avoiding Problems, Images 7-14
The closed-cell foam on the stone foundation wall at right has been extended a foot or so onto the interior concrete wall at rear to reduce conductive heat loss; the concrete wall was masked before spraying to provide a neat termination. Depending on soils, climate, and other factors, such below-grade applications are sometimes limited to the above-grade portion of the wall — or graduated in thickness, with a thinner layer below grade — to reduce the danger of freezing the footing.