I have decided to pour a concrete slab at the back of my house to replace the interlock pavers in place now. These pavers have approximately 6-8" of limestone screening support below them that will remain. Installation of a poly plastic layer and 4" of rigid styrofoam will follow. Then installation of a hydronic radiant floor heating system inside of the 4-5" concrete slab. This entire slab is going to be converted into a 4 season solarium, thereby being heated all year. The concrete slab would have a turndown foundation of 10" minimum. I seek input of wether the slab would heave as a result of frost. I live just north of Buffalo, across the pond in Toronto, Canada.