I was cleaning my shower the other day and one of the tiles popped back into the wall. I was very concerned and fortunately it was right where the access panel is. WHen I opened the panel, I noticed there is no wall behind the tile. I think there was a very thin wall (maybe plaster) and it has since crumbled away. Anyone know how to fix this (it's only a small section of wall (like a couple of tiles) without tearing anything out? I wondered if I could plaster the tiles from the back or use a backerboard? If so, how do you attach a backerboard?
