the tile was set in a wiremesh and thinset arrangement, much like a backerboard, but they stopped it at the top of the tile(about 6 ft high)then continued with drywall to the ceiling. That was the part that was damaged and had to be replaced. The house was built in the mid 70's, so whatever they did must have been an excepted practice since it's fairly well built. Anyway, what do you think of my fill-in-the-gaps remedy? Could it work?