I have to replace/update the fixtures in my 37 year old bathrooms b/c the water divertors leak. This requires removing some of the shower tile & cutting a hole in the sheet rock to expose the original fixtures. Do I have to use joint compound on the sheet rock patch since it is going to be covered up with the new tile? I ask b/c it needs 24hrs to dry b4 I can finish the job.

You'll likely get several comments about the fact that you shouldn't use drywall at all behind tile - which is true. However, you have an old shower that has been there for years so if you do have drywall behind the tile in one spot it's probably everywhere so what the heck...

You do need to seal the drywall cuts somehow. If you don't then those gaps are a clear path for water to get in behind your wall. But, since patching that wall behind the tile is not a looks thing, there are several alternatives.

1. 20 minute mud. This is a powdered form of drywall mud that is mixed with water. As you would guess, it cures in about 20 minutes.

2. Caulk - use something waterproof like silicon, a roofing caulk or any exterior grade caulk.

3. Thinset - this will cure is just a couple of hours.


You will have to add some solid blocking behind the patch area to give it something secure to rest on.

I know reality sucks but if you were to open up the wall behind the valve and peek in there and that waters been leaking for a while what your going to see is black mold, rotten framing, weaked drywall.
But what do I know I've only had to redo a couple dozen of these before.

you CAN replace a tub and shower valve, without cutting into the existing tile and or durarock
measure where the valve is on the wall behind the tub
ie.. the bedroom wall or closet, etc..tell your plumber to plumb the valve from the backside
if he whines get another plumber
it can be done.. i have done it dozens of times
the only draw back is you are locked into the same type of valve style that is there
if you have water damage..thats another story
demo wall and start over..sorry but reality bites