Effect of basement insulation on the depth of frost penetration adjacent to insulated foundations

摘要

Insulating house basements is becoming a popular method of reducing space heating energy consumption and improving the basement environment. With a reduced heat flow to the surrounding soil, the soil temperatures are lowered and the depth of the frost penetration increases. Insulation strategies must be considered carefully, otherwise foundations bearing on soils that experience volume changes upon freezing can be shifted and building damage may occur. This study reports on frost penetration measurements adjacent to nine different house basement configurations. The maximum depth of frost penetration against the exterior wall and 1.5 m (5 ft.) from the wall are reported for a number of winters with a range of freezing indices from 1249 degrees C days to 2409 degrees C days (2248 degrees F days to 4336 degrees F days). Initial observations show that only shallow, highly insulated basements with both wall and floor insulation have frost depths extending below the footings.