Hello all,
I had to remove a previously glued tile during overall backsplash installation. Unfortunately, the paper came off of the sheet rock and exposed damp gypsum. I guess I’ve no choice but to cut the damage sheetrock out and plug the hole with a fresh piece. Can I tile over unpainted sheetrock? The damage is probably 2 .5 inches square. Should I just tile over the damage and hope that the gypsum and mastic will harden together?
Thanks,
GEOMAN
Replies
I'm guessing you need to install cement tile backer board.
You need to find out where teh water is coming from and fix that problem.
It the source is through the tile, you need to develop a water proof backing system.
There are a couple of cementitios tile backers that have a surface coat that is water proof.
Are you sure it's really damp gypsum, or is it just dark-colored, water-resistant gypsum? Certainly you need to find and fix the water source if it's really damp.
If you're using mastic it's easy and reasonable to skim over a damaged area. First remove any loose paper, then prime with a shelac primer (helps bind the loose paper fibers). Scrape with a razor scraper after the primer dries to remove little lumps of crud, then skim. I recommend using a waterproof spackle for skimming, vs drywall mud.
After the skim coat has dried, go over the entire area with the shelac primer, and again scrape with a razor to remove lumps.