Question about possible bad shower build [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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07-02-2019, 12:02 AM
My house is about 16 years old in Houston, Texas. A few months ago, the master shower on the second floor began to leak. The end result was that the shower basin had to be ripped out. We opted to have the plumber rebuild the shower with a pan that can be tiled instead of another cheap basin tub. Our instructions were that the shower be "tile ready" as I am doing the tile for the shower and the floor in the bathroom myself.

The plumber finished "building" the shower today and he didn't put tarpaper or any other vapor barrier behind the backer board and didn't put a moisture barrier on the front. There are gaps of about 1/4 in between the backer board pieces. When I asked about these things, he said that anything that got past the tile and the backer board would simply funnel into the pan at the bottom via the rubber liner that comes up a foot or so. However, this rubber liner is tight against the backer board, so I don't see how water won't simply pour on the outside. I also don't see what's stopping the water from simply running down the studs and out of the pan.

I believe that the job is good enough, they just need to finish it, seal the cracks with thinset and put up the moisture barrier.

They also claim to be doing the 24 hour leak test, but they only put in enough water to cover the drain hole - as can be seen in one of the pics.

I have lots of pics, but I can't post them here as this is a new account. There is a discussion on the /HomeImprovement subreddit with pics.

Thanks for any help.

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07-02-2019, 04:47 AM
Is there a preslope under the liner, or is it sitting flat on the floor?

Got any pics of how he wrapped the liner over the curb? Especially how he made any cuts or folds where the curb hits the walls.

How low did he fasten the backer board? There shouldn’t be any fasteners lower than 2-3” above the height of the curb.

The water level in a correct flood test will be a couple inches deep. Much more than just covering the drain.

Thinset won’t seal any cracks in the backer board, but all seams should be taped with alkali resistant tape and thinsetted.

There needs to be a moisture barrier somewhere. Either between studs and backer boards, draped over the liner, or a surface applied membrane.

If he’s leaving it tile ready, and assuming proper flood test passes, is he going to pack the top mud bed that sits on the liner?

07-02-2019, 07:25 AM
it is not done correctly.

07-02-2019, 07:30 AM
They did come in a put down some concrete or something similar to make a preslope prior to installing the pan.

I don't have any pics showing the lining and the curb. Not really sure what the curb is. Is that the threshold?

The backer boards are fastened using screws. There are holes close to the pan floor - about 1.5 in above where it appears that he drilled in a screw and then undrilled it.

Is he going to pack the top mud bed that sits on the liner? I was not aware of this? He made it sound like the tile went directly onto the pan.

07-02-2019, 07:51 AM
What is the pan membrane?There should be a name or number on it.
There should be NO holes within 2" of the top of the curb.!
Is this membrane upturned on or behind the wall board? What is the wall board? Drywall? is there a name on it?
regardless still sounds wrong.

07-02-2019, 08:34 AM
The pan liner is oatey 40 mil pvc. It is turned up and behind the walls which are made of 1/2in hardi board.

There are most definitely holes that at about level with the curb. There are a few holes beneath the curb.

07-02-2019, 09:09 AM
Oatey PVC liner REQUIRES a mortar bed(typically 1 1/2") over the top of the pan, then the tile is bonded to the mortar bed..YOU CAN NOT BOND TILE DIRECTLY TO THE OATEY PAN.
Per manufacture directions and plumbing code there should be NO penetrations in the pan(except at drain) within (below) 2" of the top of the curb.The pan should be up turned min. 3" over the top of curb height including the door jamb. Pre made corners are available .

07-02-2019, 12:43 PM
Hardie board is a moisture wicker due to its fiber cement composition. I'd most definitely want to have a moisture barrier behind it that then overlaps the pan liner. It should not be embedded in the mud pan due to this unlike traditional cement boards that can be embedded without ill effect. Something like Durock is better and even slightly cheaper.

I've used Hardie board twice in an embedded mud bed situation but waterproofed with surface-bonded membrane, hence there is no ill effect since the mud bed won't get wet. Your waterproofing system is different, though.

07-02-2019, 07:01 PM
I hope you haven't paid him. Like the other said, this isn't done correctly. You might check out the "shower construction info' thread." Here's a link,

What is on the curb (step) now, just the pan liner?