We had our kitchen + addition/family room ceramic tiled 5 months ago. The floors are adjoining. There is a backerboard subfloor appropriately overlapping the two rooms. There is radiant floor heat in the family room + a kick plate heater under the sink in the kitchen to provide heat. The tile adjoining the two rooms has cracked. Would the different heating + resultant difference in tile temperature be the cause of the cracking? Would installing radiant heat in the kitchen solve the problem? there are no other structural defects that we are aware of. Please help!!