Fixing a shower built in shelf

selcouth

Hello! I've been doing some drywall work on a bedroom that is opposite a bathroom with a walk in shower. The shower has two shelves built in between the studs and it had a large piece of tile stuck to the back of the drywall in the opposite room.

I'm looking for recommendations for how to handle rebuilding the shelves. Is it ok to put the tile piece right up on the drywall from the opposite room? Do I need some sort of thin backing between it?

I've attached pictures from the bedroom looking into the shower and from the shower back into the bedroom.

pwgsx

Well it needs to be waterproofed. From the shower side you need to remove all the tiles in and around the shelf and apply a liquid waterproof membrane. Drywall as abacking will not work as well. You need a cement backerboard.

selcouth

That's what I figured. I wonder if they skipped a membrane when they installed it. How much tile do I need to remove? Just the amount in the shelf itself and the border around it, right?

joecaption

Bottom of shelve also needs to be sloped so water runs out.

pwgsx

Im wonderig what waterproof method they used for the walls. Can you tell whats behind the tile? Cement board and poly plastic sheet is sometimes used but I dont see that in your pics or cement board and redguard or hydroban or aquapel is used.

pwgsx

I would firs tstart with the tiles just in the nook and see what u fiond out. You may be able to patch it from there and not have to do much else.

selcouth

It looks like just drywall with the tile mortar. There is cement board around the rest of the shower, but not on those two shelves. I'm guessing they didn't have the desired depth with a backer so they just put it straight onto the wall.

I'm guessing I'll need to find something thin to create a barrier against the drywall and route any liquid back into the shower.