I have an old house. Person before me tiled over drywall (Not at
least greenboard!). I had a leak in the pipe to showhead that got the
drywall wet. Tile was put on with good layer of mastic so the mastic
itself is still okay. However after a week of running a dehumidifier
the paper has peeled away in spots and drywall is still crumbly. The
tile is still straight and not sagging and it's only a 2' x 3'
portion. I don't want to retile. So I am looking for a solution to
strenghten the drywall. I am thinking some good sealer paint might
act as a glue, but could act as a water trap to make matters worse?
Anyone have any ideas?