Hydroban presloped shower pan leaking how to repair

[diverdave]

I installed a Hydroban presloped shower pan and it performed flawlessly for about 10 years. I recently had some floor leveling work done in the crawlspace and it seems that somehow the guys jacked up under the shower and managed to cause the pan to start leaking. I can only assume that they jacked it enough to tear the the hydroban seam where the durock butts up to the shower pan (somehow without cracking any tile). They cracked some grout and I re-grouted thinking it may slow the leak down to insignificant but that did not work. It is a small leak (maybe 1/4 cup per shower) but enough to where it is going to cause mold and rot problems eventually.

Obviously I don't want to tear out the entire shower and redo it. Is there any other way to deal with this? I'm wondering if I can tear out the bottom row of wall tile and the shower pan and redo it or does the entire shower need to come out to ensure it is waterproof? How hard would it be to tear out that bottom row and pan w/o cracking adjacent tile? Any ideas would be appreciated.

Thanks!

[jadnashua]

Removing tile from Hydroban (is it the sheet or liquid?) still means you're likely to tear the membrane up and making a waterproof junction of where the new stuff is applied much tougher. If it's the sheet, it will tear off the fleece, and thinset doesn't stick to the base of the membrane. If it's the liquid, you are likely to get splotchy pullup of the membrane from the substrate. In either case, ensuring a solid waterproof continuous layer is iffy IMHO. That's one potential problem with a sheet or liquid membrane as opposed to a conventional liner that while the tile might crack, the waterproofing tends to remain a bit more flexible.

[diverdave]

It was liquid membrane that I rolled/brushed on. Ugh, sounds like a do over.

[jadnashua]

FWIW, it's easy to end up with a liquid waterproofing to end up thinner than it should be or have a pinhole...and connecting to the drain requires things to be done very carefully.

[Davy]

Do you remember if fabric was sandwiched within the membrane? The fabric adds a lot of strength to it. But even with fabric, it's possible to tear the membrane when stress is added like you had. Seems like to me, the easiest place for it to tear would be where the walls meet the floor.

To answer your question, I'd want to replace the whole shower floor and up the walls 2-3 tiles and up over the curb. You want the floor and up those few rows to be continuous. Doing the whole shower would be best. If you're going to have a narrow void in the waterproofing, you'd much rather have it on the walls instead of the floor. And the higher up the better.

[diverdave]

I did install fabric where the floor meets the pan and I embedded it into the hydroban per the instructions. I think when they raised the joists underneath they either caused a fastener to tear the membrane or they compressed the foam shower pan and when they let it back down the pan stayed compressed and created a tear. It's definitely not leaking from the drain, it is completely dry around the drain. The tile I used is discontinued and I don't have enough left to go up more than one row and it is iffy if I even have enough for that. Unfortunately this is looking like a do over. Oh well, there were some things I wished I'd have done differently, I guess this will be my chance to fix those things. Thanks for the advice.

[PC7060]

I admire your positive attitude!