Outside Wall - Backerboard concerns

Hi All,

I decided to re-tile my shower as I've been making minor repairs to the grout for the last couple years since purchasing the home, and I figured it was time to tear it down and start fresh.

The way the shower is laid out is, if you're standing in it facing the showerhead, there's a wall to your left which is an exterior wall, and an interior wall behind you. The exterior wall has a "window" in it, made out of glass blocks, so it's inset about 6". This is the part I'm concerned about.

I started removing tiles from this wall and noticed they were coming up extremely easy from the section under the window. The thinset on the back looked black, and the paper was separating from the drywall. The more I removed, the more obvious there was a moisture issue here (musty smell too). There's spotting throughout, and the drywall (builder did not use cement board) just crumbles. There appear to be two layers of drywall on this wall, and then it's straight against the cinderblock frame.. The house was built in '93 by the way.

So my questions are.. (1) Is the best thing to do here to rip everything out, and apply a bleach solution to the block? (2) Should I use any sort of sealer on the cinderblock and/or any sort of vapor barrier (Central FL)? (3) When I finally put the backberboard on, should I just do 2 layers of the cement board, or should I do drywall on the cinderblock, and cement board on top of that for the shower wall? I don't really care about cost, I'd like the most waterproof/solid solution.

Hoping someone can provide some insight.

-Brian

 

Post a picture of this wall with the window.
A window in a shower is just asking for trouble.
Never should have been any drywall used in a shower area.

 

Here you go, I'm not a big fan of it either. I've wondered about framing it in from the bathroom side, and stuccoing over it on the exterior.

Thanks.

-Brian

 

Welcome to the forums!

I assume your walls are furred out with PT 1x2s. You'd have insulation between the furring strips with plastic over all of it and then the drywall was installed with the tile on top of it. Today, you'd use cement board instead of the drywall ..... but that was SOP back when your house was built.

I'm not a tile guy but I've painted new residential construction most of my life including about 14 yrs in your neck of the woods. I used to live in Bithlo before I sold out and moved to tenn in 1991

 

All horizontal surfaces related to the window need to be sloped so that any splash exits to the shower/tile side of the window and does not pool up against the glass block. Even when you switch out to cement board, you are probably still going to be fighting moisture getting behind the tile. I think it is a design issue in your case.

You will also get a crash course in tiling as the window presents a tricky mix of wall tile and lots of bullnose. Take lots of pictures of what is left so that you have reference when putting the puzzle back together. Are you changing out all the tile? Assume you are if you are looking at cement board as an upgrade.

 

Mark,

You are correct on the furring. After that was a layer of Fi-Foil Vapor Shield, and then the 2 layers of drywall. Glad to hear it was SOP and not just someone being cheap. As I tore into it more I did find some cement board on a few of the steps, but not all, for the window.. and then on the ledge you see to the left.

Things have changed a LOT in this area! Thanks for the help btw.

Czizzi,

Thanks for the tip on sloping the tiles. Is there a more appropriate way of doing that aside from a thicker application of thinset, or will that be fine?

And yes, I am tearing it all out and replacing it with cement board. Pictures are a great idea, I took quite a few of that area before I started the demo. Definitely gonna be buying quite a few bullnose pieces .

-Brian

 

Check out Schluter edge treatments, there are multiple profiles and may offer an alternative to bullnose. You will have to be pretty good cutting them at the 90 deg corners though.

Schluter-QUADEC - Schluter-Systems

Send additional pictures of the demo when you have the wall opened up. I would like to see the guts before making any suggestions on slope/waterproofing.