Once the tiles come off you have to replace a larger area of backerboard than just replacing the ones that come off. It is very unfortunate this is happening in a four year old tile job. The caulking has failed at the tile to tub connection or the backerboard was allowed to contact the tub. This allows water to sponge up into the drywall.
Carl comment about cement board is correct but many showers are being done over moisture resistant drywall. To get an adequate repair you need to go up about 18". The connection of the two sheatings should not be at a tile joint. If you only go up a foot then the sheating is too elastic and they fall off again.
Post Reply
Watch this Post
