Looking for advice regarding shower pan leak [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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07-18-2019, 10:18 PM
Hello there

Got a bit of a problem, looking for some advice on next steps.

House is 10 years old. We moved in 4 months ago. A couple of days back, we noticed a fair amount of water seeping between floor and wall tile. Using spray wand I sprayed in 3 locations, water is only seeping when spraying directly in the corner. Took no more than a couple of minutes of direct spray to notice seepage. A bit surprising to me is that during the test, water did not splash on top of the curb, the water was constrained below the curb, implying that the barrier below is shot?

Anyhow, for now we have obviously stopped using the shower. Next step I am planning on this weekend is removal of the 2 exterior tiles on the curb and shower bench where the seepage is to see what's going on back there. Depending on amount of damage discovered, continue to demo tile until I get to clean lumber. It feels like I am staring down the barrel of a shower pan and shower bench demo and redo.

The shower is on second floor, no visible drywall damage below. Shower bench is flat with the exception of a slight slope on the 6 inch curb tile. I wished the bench was properly sloped all the way vs the last 6 inches. Our 2 year old, loves spraying water with the wand all over the place, which is another way of saying, there is a fair amount of water that has been hitting that general area. I am planning on having a pro do the work but I want to do the demo myself so I know what's going on and get going on potential mold remediation. I have done a couple of showers before including mudpan and put down travertine; I doubt I can achieve the results and not confident that I'd be able to get proper waterproofing with the bench and be able to tie it all in with the rest of the bathroom. There is a fair amount of travertine used throughout.

1) Is there anything else I should be doing/thinking about in terms of next steps for this? Is there a scenario that doesn't involve demo?
2) Is there general consensus on whether it's a good idea to only replace shower pan and first row of tiles vs whole shower redo? Related to this, is there a reliable way to achieve waterproofing on the wall?
3) I'll know more once I get demo, but would love any ideas on what could the problem here? What should I be looking for?

Appreciate your feedback.


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07-18-2019, 11:04 PM
Unfortunate. That is a nice looking shower. Unfortunately the shower pan will need to be redone and so will the bench waterproofing. The glass enclosure will have to come out for all that. It can be tricky to tie the wall waterproofing into your new shower pan. You are doing so much work already it doesnt make sense not to just redo the shower or at least go up a ways. Hopefully you can find a matching tile to tie in and avoid redoing the tub surround.

07-19-2019, 02:01 PM
Thanks for the reply on this. The tile seems to be round of the mill travertine, so should be able to track replacement. The same tile is used in tub surround, floor, and countertop. It's fairly extensive tile work and visually at least, really well done. I wouldn't be able to replicate those results myself. I'll keep this thread updated with findings from demo.

07-19-2019, 07:01 PM
It's really hard to say what you'll find until you start the tear out. I would look for cement board nailed on the curb which we find to be the norm these days. Keep us posted.

07-21-2019, 07:09 AM
Davy - you were right on. Among a few other problems, this was an issue for sure. The pan liner was moldy as water was trapped between the backerboard and the liner. This was on the curb and around the perimeter of the shower, 8-10 inches above shower pan. Along the curb, water was running on top of the liner and down onto the floor, worst part was where seepage was observed. Surprisingly the lumber on the curb was for the most part dry, water was running on top of the liner but not much got thru the nail holes.

From my untrained eye, here is what I observed in terms of issues with the install.

1) Backer board (some green foam stuff but I haven't seen before) was nailed on the curb and a mere couple inches above shower pan.
2) No waterproofing on the nails contributing to water getting behind it and causing mold on the liner.
3) On the folds of the liner in the curb corner and a couple spots in the middle there were nails on the inside part of the curb.
4) The pan liner itself was not sloped, it was resting on the subloor. During demo the liner was visibly wet and in the rear corners the mud was visibly wet.

To my surprise the bench was bone dry. I started demoing the bench in anticipation of damage but stopped until I figure out next steps. My goal for now was to get the mold out of there. The top of the bench has hardibacker but it appears they also put some other material, looks like tar paper or some thin liner.

So this now leaves me with options for next steps. What would you do if you were me?

I'll share what I am thinking. Demo the rest of the bench tile where it goes past the glass. Replace with a single slab tile with slope. Rebuild the damaged portion only, use wedi or schluter. My concern with this approach is how to waterproof the seams where new meets old. hopefully you would be able to provide some guidance on that.

07-21-2019, 07:53 AM
Waterproofing on the nails might would have helped it last a little longer put still isn't the correct way to install the curb. There's a shower construction thread in the liberry that shows the correct way.

You need to decide which method you want to go back with and move forward from there. You need to keep the same thickness substrate as you have behind you old tiles. I assume you have 1/2 inch Hardi. I see the pan liner going behind the back wall tiles. That probably only goes a few more inches to the seat height or a little above.

What would I do if you called me to fix your shower? I doubt the old tiles have any type of moisture barrier behind them which would cause me to remove the whole shower and start over. But if you are going to patch it up, I hope you took exact measurements from the seat to curb so the glass will fit back.

07-21-2019, 10:23 AM
The stuff behind the tiles is the same green foam stuff. I have a couple of pics below. Don't know how good/bad this stuff is. You can see there is no waterproofing on the nails. You are right, the liner goes up a few inches past the bench height. It didn't wrap onto the bench except for the 10 or so inches past the shower pan. So not sure how useful it was? Anyhow.

Still undecided what I am going to do, leaning on the patch. Any advice on how to transition from old to new?

07-21-2019, 11:08 AM
I've never seen anything with the drill picture on it, maybe someone else has. Usually if it's green, it's green board which is water resident sheetrock. It's not much better than regular sheetrock.

For a patch job, all you can do is waterproof the part you replace. In a situation like that, I'm always concerned that water will get thru the upper section that's not waterproofed and get behind the new tiles that you replace, causing problems. From a contractors point of view, I want it all waterproofed so you won't have any problems down the road. That's why I (and most contractors) wouldn't patch it. If it starts leaking in 6 months, you'll be calling. And it won't be to wish me a happy birthday. :)

07-21-2019, 01:35 PM
it sure was a nice looking shower.. you at least need to go above the bench and get a slope on that bench. lets assume that green stuff is waterproof. how did they handle the corners? lets assume the screws wont leak to much. I remember you said the curb leaked when you kept the test spray below the top of the curb? how did that happen?

07-22-2019, 07:56 AM
@Elkski - agreed. Assuming I go with the patch job, I need to remove a few more tiles so I can waterproof the where the bench meets the wall. The inside corner had mesh tape with thinset. There was no visible waterproofing done on top (redguard, membrane etc.). The leak test is still a bit of a mystery to me. My only guess at this point is that they had screws and nails below the curb height. I did notice there was some water in that corner between the 2x4's that the curb was constructed with. So possibly there was water penetration past the liner in that spot.

@Davy - The core of the stuff is foam; with seeing it in person it appears to be very similar to USG Durock UltraLight Foam Backerboard. Which by the way the installation instruction calls for waterproofing the fasteners and corners, obviously not done in my case.

Still need to decide what I need to do here...

07-22-2019, 08:43 AM
Easiest would be to remove one more row of tiles above the bench, hopefully leaving enough backing intact so you can install fresh backer board below and then use a surface-applied membrane like Kerdi or Durock membrane to cover everything. If you then let the membrane overlap the spot where the old backer meets the new, you should have a sufficiently tight assembly. Even if your old foam backer is installed without sealing the fasteners, I'd assume that you're probably good, as 90% of the damage you see in a shower will be below that area.

Is that a niche or a decorative frame on the center wall? If a niche, I'd be more concerned about water damage there as well if your spray hits it directly.

07-22-2019, 09:02 AM
@makethatkerdistick - it's a decorative frame. Yes, even though it's fairly certain that they didn't do proper waterproofing, in the past 10 years of use, the damage has been constrained down below. Also no damage at the faucets. This sounds like a good plan. It's hard to keep the foamboard intact, I'll do my best.

07-22-2019, 09:18 AM
Yeah, you certainly don't want a gap between your surface membrane and the foam backer. That will be your challenge to keep it intact. At any rate, with the bench and all, the surface membrane will be so much easier (and frankly, better) than a vinyl liner. For the transition between the membrane and the foam backer I'd use something like Kerdifix to make a truly good connection.

Obviously, if you go with a surface membrane, you'll also have to use their proprietary drain. That's crucial.

07-22-2019, 06:04 PM
Cool. Thanks for the valuable feedback. I need to think about next steps; tear out and start over or patch existing.

01-02-2020, 10:31 AM
Well, after multiple unsuccessful attempts at getting contractors to do the work, I decided to tackle this myself. I wasn't confident that a patch work would do the trick, so I ended up doing a complete tearout. Also, since the transition between old and new would be challenging to get it right and looking good, I decided to add a pony wall. The schluter system was pretty good, first time installing it. the pan/kerdi drain is by far the best part of the system, much easier to install than mudding in a pan. Although not shown on the pictures, I went over all the patches/seams with a liquid membrane (Mapei Aquadefense) for good measure. I am not as confident in the kerdiband/mortar alone.

I did make a goof and looking for advice. I forgot to slope the curb and the top of the pony wall. I did get the bench sloped (1/8" per foot).

The curb is constructed out of 2x4s, wrapped in 1/2" hardibacker, wrapped in kerdiboard, wrapped in kerdiband, with the aquadefense on top. Pony wall is same.

I am planning on doing a solid piece of quartz on top of the curb and pony wall.

Thoughts on correcting this?

My plan was to put another 1/2" hardibacker on top of the existing structure, Then wrap that in kerdiband (I assume it's ok to kerdi on top of hardibacker), and put the aquadefense and call it good. My question would be on whether it's sufficient to just use a bed of mortar for the hardibacker and skipping nailing it. I hate to drill thru all the existing waterproofing if not necessary.

I assume sloping the quartz alone is not a good idea, but interested to hear thoughts on that.

Thank you all!

P.S. Hope it's OK to revive older thread since it's same project.

01-02-2020, 11:09 AM
Welcome back, Chris.

Since you're going to use pieces of quartz, thus no grout lines except at the corner, I'd simply slope them all as necessary using spacers and mortar.

1/8" for the bench isn't much, and as it will get a lot of water on it, I'd have to spring for a piece of quartz ontoppa that, too (my corner benches have a lot of slope and though a good bit of water runs off a good bit remains from surface tension).

01-02-2020, 12:48 PM
Thanks Dan for the prompt reply. First of, I forgot to mention that yes, I will be doing Quartz for the bench top and for the niche top as well (may be hard to see in the pictures, but on the inside part of the pony wall I installed the 12x12 kerdi niche. I will add a bit more slope on the bench, I have read conflicting info anywhere between 1/8th to 1/4th per foot. Good to know from experience what works best.

Regarding the curb/pony wall, good to know that I can just slope the top. Saves me a bit of additional headache. I will be outsourcing the work of getting that quartz installed, I will make sure installers slope them. I'll make sure to let them know that they need to miter the corner of the pony wall to handle the slope.

01-02-2020, 01:32 PM
Best practice is, of course, to have the substrate properly sloped to drain but, given your situation and the use of the quartz I wouldn't sweat it.

Here's what I know from mine. My 27" long pony wall is capped with a piece of soapstone that's about 6" wide (as well as the vertical end of same wall), and it is sloped at a bit more than the recommended 1/4" per foot. The glass panel sits on the stone, the gap filled with clear silicone.

After a shower, and despite the slope, there is STILL a significant amount of water sitting on the stone; water that gets splashed on the glass and runs down, and water that splashes directly onto the stone. Surface tension, and perhaps the bit of texture in the stone, is holding onto the water. I'm not sure if 1/2" per foot would be enough.

Since I squeegee the glass, every time, I simply squeegee the top of the pony wall too (I squeegee the whole shower actually). Had I known then what I know now I'm not sure I'd have bothered with sloping the top of the pony wall at all. Maybe water won't be as clingy on quartz.

So, IMO, up to you on the pony wall. You will want the installers to fill the miter with whatever goo they use to fill joints where two pieces of quartz meet, that should waterproof that miter joint.

My guess is you'll be squeegeeing the glass, the top of the pony wall, and the bench. At least.

01-02-2020, 01:53 PM
Good points, particularly about best practice. I still can't believe I made the goof.

Anyways, I will make sure quartz installers and glass installers do a good job on waterproofing seams. The reason I am redoing this whole shower is due to poor workmanship to begin with, trying to avoid the same mistake.

Yes, curb and pony wall will be about 6" for me as well (I sit at 4.5 inches right now + tile + overhang will get me to about 6).

I was going back and forth on doing the vertical piece of the pony wall with quartz. I was originally planning on having it cut at a shop and do the install myself so didn't think I would be able to get the fit and finish right. But since I am going to contract it out, and reading your post, I will have them do that. I feel better to have fewer seams on these transition surfaces.

Thanks again, I feel more confident now on proceeding to the next step on this project.


01-02-2020, 07:30 PM
You did the right thing when you tore it all out and started over.

01-02-2020, 09:37 PM
Yeah, I wouldn't feel right if I had patched it, not only for me but for the next owner. This is best. I'll keep this thread updated, looking forward to getting this fixed, it's been a long time. This weekend I'll get tile ordered and line someone up for the quartz install.