Discuss Incredibly Perplexing Shower Tile Problem in the American Tile Setters Advice Forum area at TilersForums.com

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Greetings All, appreciate the expertise existing in this forum.

I am a home remodeler, not a professional, but have done 4 homes completely down to the studs, including many many square feet of tiling floors, wall, ceiling, bathroom.

I have a very difficult problem to diagnose. I have a leaking shower pan/wall (not sure), that essentially is filling up the shower liner "bowl" and overflowing over the top of it, inside the wall cavity. My question is, if the shower was built correctly, would it be normal for water to make it to the pan liner at all?

Here is what I've done:

1) Built shower walls, with wood blocking 8in up from the floor. Wood subfloor on bottom, covered in concrete board

2) Put in cement sloped (minor slop) floor, to center drain hole

3) laid in Oatey gray pvc shower liner, and nailed 12 inches up wall. Folded all corners, used glue and Oatey corner damns.

4) Put in additional cement slope floor over top of liner, sloping to center drain.

5) cut liner X over Oatey drain flange/base, sealed and clamped down nicely

6) water drain test, 4 hours, no loss of water

7) Full layer of 6mil plastic over all walls, overlapping inside shower liner by 6inches. Installed concrete board on wall, down to about the 3in mark above floor liner. Taped and Cement sealed all seems in concrete board, including 17" corner seat

8) covered ENTIRE shower with two full coats of Mapei Aqua Defence

9) thinset and shower tile installed, used leveling system

10) grouted with Fusion Pro grout

I have access to the walls on three sides of this shower, so have been able to open them up as part of the diagnosis of this leak. I can see the back side of the plastic sheeting, and near the bottom of the walls, can see the shower liner going down to the floor.

Now, if you point the shower head at floor only, you get no filling of liner bowl, no leakage

If you point the shower head at the seat, within 60 seconds there is filling of the liner bowl (you can feel it like a balloon on back side of wall), and eventually it fills up to top and overflows.

On the shower tile site, I've used a magnify glass and hi power light to look for ANY crack in the grout. Nothing. I've even silicone caulked all corners.

Could anyone make a guess how water is getting into the shower liner so fast?

Attaching some photos at this location: shower-leak-photos – Google Drive - https://c.aprilsteve.us/3A8SxVp

Cary, NC


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Oh dear! Have you discovered what the problem is yet?

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