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.
Unless you turn down the edge of the slab to below your local frost line it is susceptible to heaving.