Does ground under exposed concrete have a deeper or shallower frostline?
if you have a 10x16 concrete slab or even a unheated shed will the frostline be as deep under the concrete as it would be 10 feet away. Ground is mostly sand
if you have a 10x16 concrete slab or even a unheated shed will the frostline be as deep under the concrete as it would be 10 feet away. Ground is mostly sand
The frost line below a slab on grade depends on the climate zone, what is on top of it, whether it’s heated, and if there is insulation under the slab.
A simple slab on concrete with no building on top, and that has no insulation underneath would have the same frost line as the surrounding ground. If it had a warm building or was insulated underneath the concrete, then the ground would be warmer underneath. What would change the ground temperature under a slab compared to land 10 feet away is insulating or heating it in anyway. If you explain what you are hoping to build, whether you planned to insulate under the slab and the climate zone you live in then we may be able to offer more help.