Is this going to cause problems? Having full bathroom refit and tiler in at moment tiling floor and putting in underfloor heating mat. Just went in to check after work and I can see the ufh mat extends to under where the bath will be (not completely) but by a few inches. Everything I have read says NOT to do this - I don't know if it is just because it's a waste or because it might cause problems with bath seal or something? As it's down and floor is half tiled already I'm sure it's too late to change so I'm worried now. Should I be?