Anyone ever done any tiling? I have a bathtub/shower combo and looking to do a little upgrading to it. Right now it has 3 walls of tile that go 3/4 up to the ceiling. I'm thinking about upgrading the tile to something newer and extend to the ceiling. My question, where the tile stops now it is just painted drywall board. It doesn't get wet right now just steamy from the hot water. Would that be ok to tile over, or would I need to cut out that drywall and replace with backerboard? Thanks!