Our 1600 SF basement has a slab floor with no insulation underneath. I'm redoing the bathroom (roughly 100 SF, with 7' along the foundation wall) and would love to put in radiant floor heating, but I don't want the floor to be 2" higher than everything else to allow for insulation over the slab.
I'll be jackhammering out significant portions of the floor to reroute plumbing already. Could I replace the slab in the bathroom with something more conducive to radiant heat (e.g. rigid foam with a framed floor on top), or put down rigid foam and pour a thinner slab on top of it? What problems could these approaches cause?