Leaking shower behind wall. Curb too low? Pics

[JStyles]

My shower was constructed about a year ago. Some of it may have been over the head of the contractor who did it, who turned out to be more of a 'handyman', good at carpentry not great at this sort of work or tiling.

I've got a leak, very definitively from the LEFT side (see photos) on my shower (the controls are on the left), the shower head is on the right. Its a large shower about 7 feet weed (we almost never use the rainhead). The left (control) side does NOT get wet, but that's where the water is coming from, under the shower its bone dry on the right (head side). It only starts leaking after a long shower, so there's some pooling going on.

I've checked behind the walls with an endoscopic camera (everyone needs one by the way) and see no water coming from the water supplies - so its a drainage problem. The whole shower needs to be caulked (he grouted corners instead of caulking them), so that's definitely a source of water entry - but despite the water seepage, there must be insufficient sealing to not accommodate for that (right?).

Shower seems to be speced correctly. Sloped mud, with a PVC liner on top of it, liner was properly wrapped up the walls, I inspected prior to tiling, no nail holes or anything dumb like that, but I'm no pro. Walls were cement board that was also Red-guarded up the ceiling. I haven't used the shower in 2 days and the grout between the corner of the floor and the wall (should be caulked) is still wet, so I'm thinking water is pooled under the tiles on the liner and is wicking all the way to the other end for some reason.

The curb is very low. On the inside of the shower there is a gap that was filled with mortar which started to crumble so I've removed. Hard to see from the photos but the liner IS in there and is correctly wrapped over the curb ... But its very low. Maybe half an inch higher than the tile surface (though again this area is far from the head and is not getting that wet ... directly).

I hope I don't need to deconstruct too much - but what should i do? I'm hoping you don't tell me rip it all out and start over because I actually think a good amount of it is built correctly - but the curb is questionable.

I don't want to hack it - but my first instinct was to fill that gap under the curb (which I think is acting as a channel) with closed cell waterproof expanding foam and then silicone it closed. Can I patch on some extra liner and raise the curb? I'm grasping here. Thanks for your help.

 

[Jadnashua]

FWIW, your shower should not leak even prior to the tile, grout, and caulk is applied. Tile is a decorative wear surface, not waterproofing.

Code calls for the curb, or opening, if there's no curb, to be at a minimum of 2" higher than the drain. Can't tell on yours if that's true.

Since you can't tile directly to the liner, your curb would need some metal lath and mortar applied over it prior to then installing the tile. No fasteners allowed inside of the shower within 2" above the curb. If the mortar is crumbling, that implies movement, which needs investigation. The top of the curb should have a slope into the shower. A level surface can lead to pooling and maybe leaking.

Could it be leaking inside the wall at the shower arm? While not particularly easy unless you're using plastic bits, overtightening the shower arm could split the fitting in the wall or it may not have had a good application of pipe dope or tape.

You might want to check out www.johnbridge.com where the whole site is dedicated to tiling.

 

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[JStyles]

It's not the shower arm. I ran the shower literally shooting the water out the window and there was no leak. I pointed it at the grouted corner that's deteriorating and it was leaking pretty rapidly. But it's not leaking from under that corner, it's actually going to the other side of the shower 6 feet or so. So the poor grouting (that should be caulk) is letting water pool ... And I'll fix that, but before I fix it I want to fix wherever the water is exiting from.

Based on the slope, the curb is going to be at least 2 inches above the drain.

The curb I believe has an appropriate slope, though even if it didn't, to be honest it barely gets wet at all based on how wide and long the shower is. Also, this is an aggressive leak, that will happen if I spray no where near the curb. I only mention the curb because I think it's the ultimate point of exit for the water.

Even the area under the curb (with the cracked mortar), barely gets wet. With this contractor I'd more likely to blame the cracking mortar on bad mixing, my girlfriend and I are both pretty light and we don't stand on the curb, do there isn't going to be much if any movement.

 

[JStyles]

I'll actually revise and say maybe the top of the liner isn't quite at two inches above the drain... At least from the very top of the drain. Not the be dismissive of the code, but how likely is this to allow the leak. The shower drains very well, no pooling. Nothing is going up and over the curb.

Also, just took a closer look at the front edge of my linear drain. I'm guessing this should have been caulked? This would likely be a pretty pervasive entry point for water to do directly down to the mud bed and sit on the liner. I've identified plenty of obvious points of entry but I don't want to even fix them yet if it masks the problem .... Maybe it won't leak during a 15 minute shower but will it leak during an hour long shower. I'm thinking it's a good idea to figure out how the water is exiting but I'm dry on theories. And just to clarify the leak is coming out on the opposite side of the drain/showerhead ... So the high side.

 

[Jadnashua]

Generally, any change of plane or materials gets caulked. Some engineered devices are designed to have grout up against them, so can't say for sure on your drain assembly. But, how is that drain attached to your liner? If your linear drain doesn't have weep holes, then any moisture that gets down into the mudbed will just pool and accumulate. Again, the shower should not leak even before the tile is installed. You should not have to add caulk to prevent it from leaking. Did the installer perform a flood test?

Second, regarding the curb, it's the top of the curb that should be at least 2" above the drain. That's more for overflow if the drain got plugged than for normal operations...it should give you notice before it overflows so you can shut the water off or stop standing on the drain (hard to do with a linear drain!). It should work fine in normal circumstances with a lower one, but technically should not pass an inspection which is looking for worst case scenarios and minimum requirements.

 

[JStyles]

According to the instructions it actually shows grout right against it. Though my grout is definitely shrinking it something because there's a pretty healthy gap there.

It's connected into a No-hub Shower Drain Base. It's
definitely possible that they didn't put the pebbles to unblock the weep holes of the drain base. I'm guessing I can't pull the drain out without damaging it or the mud it's set in?

I'm not sure if they did a flood test, I honestly can't remember .

I hear you that it shouldn't be leaking regardless of the tile, caulk and grout, which is why I don't want to repair that yet, as it would probably just slow the leak but not fix it.

Not sure how to otherwise track down where it's leeching out.

 

[Jadnashua]

That gap will allow more water to get into the mudbed than desired, but if the weep holes are open, and the clamping part is properly attached, it still shouldn't leak. Is the grout sanded or unsanded? If unsanded, that typically tends to shrink more than sanded, which is the main reason why unsanded can't be used in grout joint widths larger than about 1/8", which yours is.

Which cbu did they use? Because you cannot put fasteners down near the bottom since you can't have fasteners lower than 2" above the top of the curb, it makes it tough to use something like HardieBacker (which is a fiber cement board and must have a gap between it and the mud bed) versus a true cement board, which can be embedded in it to help anchor the bottom in place. FWIW, moisture will wick up the cbu, and, if you used REdGard on the front of it, that means moisture will get trapped between the cbu and the wall...not good since the mudbed in a conventional shower of a well used shower does get damp and will stay that way.

 

[JStyles]

The backer was regular cement board, not Hardie. I can't say for certain if it was installed with an appropriate gap from the mud, so I can't say if it's likely wicking.

The shower floor tiles are actually 2", and that grout line is a hair under 1/8 (I'm measure 3/32). Grout is unsanded. Though the the grout line between tiles is 1/8, along the walls and along that drain it may be wider, so maybe shrinkage is happening opening up that gap.

Is there any likelihood I can remove the drain fixture to inspect the weep holes of the drain base?

 

[Jadnashua]

The TCNA has two different install procedures based on whether the board is fiber-cement (Hardie) or 'real' cement board...Hardie cannot be embedded, a 'real' one can, and actually should be to hold the bottom in place since you can't use screws to hold it down at the bottom. The changes of plane should not be grouted. Movement there often ends up cracking grout. Still, that should not allow a shower to leak if the underlying structure is done according to industry standards.

 

[JStyles]

Suggestions on what to do about this? I'm not sure what to look at next to determine where or how water is exiting the envelope of the shower.

 

[WorthFlorida]

You really did not say where you see water unless I missed it. Is this on a slab (a Levit home), first floor with a basement or second floor?

Grouting all corners with wall tile is common and caulking is not required. Yes, overtime the grout shrinks and the walls move from humidity cycles you'll see hairline cracks in the corners but never large enough to cause major issues. Your walls are coated with a water proofing RedGard. If you are sure there are no leaks from the valve body to the shower heads, I would almost be certain it is the gap at the floor. The water is slowing getting between the shower floor and wall.

Fixes? Unless it is 4" square old fashion square tiles with 1/16 " nubs for a grout joint, always use sanded grout. Its stronger and less likely pop out or crack overtime as unsanded grout will.

I had a shower with 4" tiles and unsanded grout. When I demo-ed it for a remodel, the old blue board under it had a coating of mold because the unsanded grout is very thin and porous. The floor tile of the same kind had water under it in the groves of the thin set from the trowel when it was installed. It was a recessed concrete floor so water could never could leak out. Code has changed since 1990 and rubber matting is required. Since you have RedGard on the walls I doubt that is where your leak is from.

To repair the corners and you want to use caulking, use siliconized caulk and put a tiny bead down the corner or on your finger and push the caulking into the cracks. Do not cover over the entire joint like your doing a window. With a damp rag wipe the corner smooth to the grout surface. When dry you'll never see any unsightly caulking.

To close up that gap up is a tough call since it is hard to see from the picture. You can try to see if this works. Get hydraulic water proof cement. Towel it in the gap but do not take it flush to the tile. Leave maybe a 1/8" recess so if it does stop the water leak you can cover it with white sanded grout for a nice finish.

After it is all said and done with no leaks get a bottle of 511 Impregnator Sealer at HD. I've used this product and works very well. On vertical grout lines brush it on the joints and allow it to soak in. After ten minutes or so wipe up any excess. After drying for an hour or two do it a second time or more until the sealer beads up on the grout. If any of your tile work is marble or natural stone you do the entire surface. You need to do the floor grout maybe two or three times a year if it is used daily. The floor gets really beaten up with soap and tile cleaners so don't believe the label of 20 years. Maybe if the tile is on the ceiling. With all of the small tiles on the floor you can coat the entire floor to get all of the grout covered.

I hope this works out for you.

 

[hj]

Grout or caulk, it is immaterial. If the vinyl liner was installed properly, it is impossible for a leak to appear outside the stall until it also is deep enough to overflow the curb

 

[WorthFlorida]

Yes, if it was installed correctly. Having a gap like that looks bad and a good place for mold growth. It could be the floor drain area and there I would use caulking.

 

[JStyles]

You really did not say where you see water unless I missed it.

This is a second floor bathroom. The leak was seen coming from the ceiling on the Left side of the shower (beneath the controls). (I was pretty convinced it was coming from the supply lines, but I've looked behind the walls thoroughly and its all dry.

I removed the ceiling drywall and can pinpoint at least where its coming out ... its essentially directly below this front left corner (see pic below). I can see under the joists, the whole right side of the shower (pretty much the entire underneath of the shower) is completely dry. I've removed this baseboard near and there was some moisture there. Even looking under the curb threshold I can see the mortar is wet. Now mind you, water doesnt get anywhere near this (maybe droplets), the shower is about 7 feet wide and the left side of the shower is bone dry.

I DO know that the contractor was unable to get a PVC liner long enough and did glue two together... so there's a seam maybe one foot off of the left wall... a foot or so from where the leak is showing up. I saw the finished work, it was solid as I can imagine. Again this is several feet from where any water hits, though if it pooled and wicked up beneath the tile it could make its way uphill there.

This is a 2 inch tile with just under a 1/8" line, unsanded, could we even have used sanded?

I'm ok with not using this bathroom for a bit (I can hold it in)... I'm thinking I'll bleach everything thoroughly. Give it a rinse and then wait a week or more to try to let it dry out as much as possible. I'm picturing a pool of water/mold beneath the tiles at this point. Then I'll caulk the walls, caulk the wall/floor joint, caulk the lip around the drain, hydrolic cement under the threshold and grout, then sealer as suggested.

These tips were very helpful, thanks. I'm realizing I havent yet gotten to the exit point though - what would a plumber do, whats the first thing they are going to start opening up to get a better view?

 

[WorthFlorida]

Water could be traveling under the tile. Gravity always wins. The water proof membrain needs to be one entire piece with no seams and a few inches up the wall.

Take the floor drain cover off and plug up the pipe. Then pour water from a pail and fill up the base a little at a time to about an inch. From the ceiling below look for your leak after adding water. It will prove that it is not any water lines and it’s leaking from the base. If it does all the caulking in the world won’t stop it if it is traveling through the grout.

This is my own master bathroom on a slab done by a licensed plumber. An air bladder was placed in the drain and water added an it passed the rough in inspection. Final product and tile is green marble and it was sealed.

 

[JStyles]

Water could be traveling under the tile. Gravity always wins. The water proof membrain needs to be one entire piece with no seams and a few inches up the wall.

I get that one piece is better, but the manufacturer of the liners sells "shower pan liner adhesive" so I'm thinking if done right this shouldn't be an issue. I saw the liner once joined because the contractor specifically pointed it out to me so I wouldn't worry about it.

That shower looks great, I assume that's not finished and you added a glass panel on that bench?

I could try this bucket flood test, but I'm confident that the leak isnt from the supply. I waited until I saw a leak, turned off the water, let the leak stop, then put the shower head and shot it right out the window for several minutes and the leak didn't show up. Pointed the head at the wall and the leak started back up quickly. Its not leaking from that wall, its just the inlet to the water getting into the shower bed and somehow leaching out 7 feet away. Gravity wins, but not in this case because its going upstream.

 

[WorthFlorida]

From the valve to the shower head, how are the pipes run? One last try for the water supply. Remove the shower head arm and replace it with a 1/2 inch plug. Turn on the water, first cold then hot and wait for any leaks.

 

[Jadnashua]

A properly done seam is fine with a liner. You also need the curb corners to seal the cuts required to get the liner over the curb. If the top of the liner isn't sloped into the shower along with the top of the buildup that has the tile on top, moisture can pool and leak out there. About 6' wide is the widest liner that I've seen, but narrower is more common. Depends on which way your run the thing as to where the seam will end up, if it needs one. Most of the liner material is narrower, closer to 3', or a meter.

This is the sort of question you'll get lots more review with over at www.johnbridge.com where the site is devoted to tiling things. There's also a forensic tile inspector that frequents that site.

Keep in mind that water will flow, sometimes long distances, so where you see the leak isn't necessarily where it originally came from.

 

[WorthFlorida]

.......Its not leaking from that wall, its just the inlet to the water getting into the shower bed and somehow leaching out 7 feet away. Gravity wins, but not in this case because its going upstream.

Water can only go uphill with pressure behind it so I’m leaning toward a water pipe leak. It can take a few minutes to show since a pin needle size hole will take awhile to show itself. On my own bathroom remodel 12 years ago I had a bad sweat joint between the valve body and shower head. Of course it only leaked during use and it took years for it to show itself on the garage wall.

 

[JStyles]

From the valve to the shower head, how are the pipes run? One last try for the water supply. Remove the shower head arm and replace it with a 1/2 inch plug. Turn on the water, first cold then hot and wait for any leaks.

Its possible that this could yield different results since it would be putting some back pressure on the supply line. They are run up from the controls, across the ceiling and then down (I'm almost certain). I dont have a cap on hand, but ill first take a look behind the wall, I havent endoscoped that side yet to see if any moisture below the shower head. That all said - the association seemed to be pretty clear when I sprayed the water out the window, no leak, when i sprayed it at the degraded corner, it leaked aggressively. I won't write off the idea that its leaking though, I'll scope the wall it should be evident if there's any moisture near the shower arm.

A properly done seam is fine with a liner. You also need the curb corners to seal the cuts required to get the liner over the curb. If the top of the liner isn't sloped into the shower along with the top of the buildup that has the tile on top, moisture can pool and leak out there. About 6' wide is the widest liner that I've seen, but narrower is more common. Depends on which way your run the thing as to where the seam will end up, if it needs one. Most of the liner material is narrower, closer to 3', or a meter.

This is the sort of question you'll get lots more review with over at www.johnbridge.com where the site is devoted to tiling things. There's also a forensic tile inspector that frequents that site.

Keep in mind that water will flow, sometimes long distances, so where you see the leak isn't necessarily where it originally came from.

I cant vouch for curb corners, and in my low res photo I don't see liner corners - so it could definitely be an issue. The seam was done in a pretty safe spot, as far away from the shower head as possible. A third of this shower doesnt even get wet. It looked pretty solid too me, it pretty much melts that rubber together.

I'll post to that site as well, thanks. I hate when threads go dead without resolution, so either way I'll continue sharing here until the problem is fixed.