Foundation depth for deep soil frost line

[Ed_]

Originally Posted by jpark1wirrcom

ESB: frost-protected foundations only apply to heated structures, where the heat loss migration is trapped by the insulation under and around the foundation.

If you look at the last image in the page I linked, it applies specifically to a non-heated structure. The idea is to insulate and take advantage of the earth's latent heat to raise the frost line.

Ed

[jpark1wirrcom]

I stand corrected. The unheated version works differently, would save on excavation costs and use cheaper materials(gravel/sand bed instead of deeper foundation wall pour)