Acrylpro, I'm not sure what to do next....

[jadnashua]

The industry bible on tiling things, at least in the USA, is the TCNA Handbook (Tile Council of North America) where they detail the procedures that have been verified to work. There are a lot of them. None having you tiling directly on a gypsum based product IN a shower except for B422.x, but that requires a waterproof sheet membrane to be applied over the material...making it entirely waterproof before the tile is installed. Unless you've left something out, you do not have that situation, and if you did, use of a mastic over a waterproof membrane is even worse than probably just over drywall, moisture resistant or not. The stuff stays pliable in a bucket for probably at least a year for a reason...it can't dry out. Same idea between an impervious tile and a waterproof membrane which is why they don't recommend it - a thinset is a less expensive, better alternative. It does take a bit more time to mix up properly and then clean up, and once mixed, if you don't use it all, you throw it away rather than just put the cover back on the bucket.

[Davy]

I know you're worried about the ceiling but once the mastic dries, I don't see you having any problems with it. Usually, there's not enough moisture that will get thru the tiles up there. Most problems will be in the lower 3 ft of the walls. Since it's already done, if you can't get the installer to retile if properly, use it a few years and yank it out and start over.

With a mastic installation like that, you might buy some time if you can get in the habit of drying the shower after each use.

[Rickytileguy]

Ok - so after a lot of thought and a long conversation with my wife we decided to fire the current contractor and we're going to hire someone else.


EDIT: I have purchased the TCNA Handbook for 2014 - Ceramic and Glass Tile - Bath and Shower Installation Methods. I'll make sure the new contractor follows the rules.

[Bruce D]

Great advice. Just demoed a drywall shower with no waterproofing, except hot mop tray, installed in my home as a 1980's remodel. The tile was all that was left. All wood was turned to powder including subfloor and attached tub surround. Hired framer to replace all including sistering two joists. Starting over with proper build will save in the long run.

[Rickytileguy]

I agree. It's a real pain in the *BEEP* but I'm already feeling better knowing it will be redone properly.

The new guy is going to install waterproofing around the shower then install cement board. Then, the tile will be attached to the cement board using the correct thinset.

Thanks to everyone for your help and advice. I truly appreciate it!!

[GregO]

Ricky,

Tell us a little more about waterproofing before installing cement board. Usually it's the other way around (unless you meant a moisture barrier such as poly sheeting installed beneath your CBU).

[Rickytileguy]

So this is what he is saying from the outside in (this is an interior shower).

STUDS > Vapor Barrier> Concrete board > Mapei Ultraflex LFT > Tile


Thoughts?

[GregO]

Ok, that's what I was hoping to hear. Sounds good.

[jadnashua]

Millions of showers built that way, and when done correctly they work.

One subtle point, and the TCNA handbook covers this, there is a slightly different method depending on the type of cbu used. Essentially, there are two types: essentially actual concrete, and fiber-cement boards (HardieBacker is an example of this type). WHere and how the backer is installed relative to the pan is different between those two types, and you and the contractor need to be aware of it. Either will work, but not if you don't follow the exact procedure.

I prefer one done with a surface waterproofing, but that's another story altogether.

[Rickytileguy]

jadnashua - where does it say the techniques? I cant find it in the manual. The guy doing the work is going to use cement board, not Hardie Board.

EDIT: I found it (I think). It states that the cement board should not be screwed in lower than 3" above the shower pan.

[Kman]

I think you, and maybe Jim, are referring to showers with a mud bed and liner. Since this is over a pre-formed shower base, different rules apply.

[jadnashua]

I think you, and maybe Jim, are referring to showers with a mud bed and liner. Since this is over a pre-formed shower base, different rules apply.

Yep, my bad...I was thinking a traditional mudbed. You do not want to burry fiber-cement products in a mudbed.

[Rickytileguy]

Hello,

I'm installing a sliding shower door in my shower and I have an issue. The area where the shower door rail is to be attached there are no studs. There is only tile and cement backer board.

The glass is pretty heavy, so I want to make sure that I attach this rail very well. I'm obviously going to drill through the tile, but what do i use as far as an anchor for the cement board? I'm not sure if a standard drywall anchor will even work in a cement board.

Thanks in advance!

[nolala]

Do you have the option of opening the wall up from the other side and adding studs? If so I would think that is the way to go.
I know my glass panels are extremly heavy and would not want only the CBU and tile holding it especially if the glass hangs from the top.

[Rickytileguy]

I have the option to do that, yes, but the real question is .... do I have to? I've just finished redoing my entire bathroom and I'm so close to having no more dust... If there are no anchors then that's what I'll need to do. The screws that come with the shower door kit are not very bulky, and there is a bottom rail as well that I'm assuming will take some of the weight also. Knowing that, I'm not certain that I need to anchor into the studs.

This is the product: http://www.homedepot.com/p/Aston-60-...5yc1vZbzcgZ7nv