Richard, I had to break out some tile last year to repair a pipe in the bathtub. When I did, I found that there was nothing holding up our tile (Iam not sure how far up). Whatever the tile was adhered to at one time is GONE! It looked to me to be just rotten. We had someone come out to give us an estimate and he thought the damage was caused by carpenter ants and didn't even want to estimate. I really can't afford to hire a general contractor to repair this. I'm not sure how far up the damage goes. It looks like someone just did a quick fix to hide this damage when we bought this house 12 years ago. My husband has a physical handicap and can't help. I am usually very capable with do it your self projects. Should I just start busting out tiles till I get to some good backing like you said? I would appreciate any advice you might be able to give me. I think I could do the retiling but it is what goes behind the tile that scares me. Thanks very much.