frost-protected shallow foundation

frost-protected shallow foundation

A construction method that uses insulation and drainage to artificially raise the frost line of soil to a level that allows relatively short—shallow—foundations.In cold climates,building foundations must extend below the frost line to a depth of soil that does not freeze. Freezing causes soil to heave upward and then sink back again, shifting everything on top of the soil. It does not result in a very stable building base unless one takes steps to prevent soil movement.