Slab question

[Brass_Machine]

So I have been perusing the board and drooling over some of the garage builds... However, I do have a question... In some of the pictures where a slab is being poured, I see some people have been sandwiching in foam boards.

Why?

Is it only for radiant heat?

Eric

 

[6768rogues]

You can insulate a concrete floor by placing rigid foam insulation under the floor. An alternative way is to insulate the sidewall down below the frost line and then insulate under the floor to two feet inside the outside wall. Rigid foam has a high compressive strength, and can support concrete.