Kerdi Shower Kit, Water Leak Test Failed

[bitshifter]

Hi, I'm working on a bathroom remodel. I've installed a kerdi shower kit and have experienced a leak in one corner of the shower kit. I read through the instructions and followed as close as possible and referenced this video as I had ditra heat installed over top the kit:

.

I've attached a few photos of the leak under the drain pan corner and above with the related corner. I'm curious if I used too much thin-set applying while applying kerdi band or just didn't quite get the application right. I removed the band covering the area with leak and laid it to the side for reference (attached pic). The foam support in pic was just temporary while glue dried. Any info is greatly appreciated. I can supply more images if necessary.

 

[Jeff H Young]

Never built a shower pan myself . We use hot mop by professional waterproofing contractors that only build shower pans every day .
Id recomend watching video , contact Kerdi. dont know the process for repair. Looks like a good system though

 

[Sponsor]

 

[MTy]

Hi, I'm working on a bathroom remodel. I've installed a kerdi shower kit and have experienced a leak in one corner of the shower kit. I read through the instructions and followed as close as possible and referenced this video as I had ditra heat installed over top the kit:

.

I've attached a few photos of the leak under the drain pan corner and above with the related corner. I'm curious if I used too much thin-set applying while applying kerdi band or just didn't quite get the application right. I removed the band covering the area with leak and laid it to the side for reference (attached pic). The foam support in pic was just temporary while glue dried. Any info is greatly appreciated. I can supply more images if necessary.

I recommend you hop over to www.johnbridge.com. The folks here know their plumbing stuff, and some know kerdi showers too, but all they do over there is help folks with tile and shower issues. They helped me build my kerdi shower.

 

[Jeff H Young]

proper way to fix a leak when you cant tell exactly where leak is not a simple answer. plus do you want a proper fix or one that passes test?
Id just be real careful how I proceed sorry nothing even remotely specific here. once its tiled these really become serious

 

[bitshifter]

I recommend you hop over to www.johnbridge.com. The folks here know their plumbing stuff, and some know kerdi showers too, but all they do over there is help folks with tile and shower issues. They helped me build my kerdi shower.

Thanks, just registered. Waiting on access.

 

[bitshifter]

proper way to fix a leak when you cant tell exactly where leak is not a simple answer. plus do you want a proper fix or one that passes test?
Id just be real careful how I proceed sorry nothing even remotely specific here. once its tiled these really become serious

Exactly, why i ran my leak test before tiling. I'm trying to get some additional direction or at least some feedback before I proceed. I also contacted the kerdi guys. Will keep you posted. Thanks.

 

[Travis K]

Looks like the thin set didn't adhere to the kerdi. Maybe it was too dry. I have done dozens of kerdi pans and never had one leak.

 

[Jeff H Young]

I'm not familiar with the kerdi but interested in your case.
Travis mentioned thinset, surely a shower pan wouldn't rely on thin set to be water proof ? its gotta have a membrane of sorts

 

[MTy]

I'm not familiar with the kerdi but interested in your case.
Travis mentioned thinset, surely a shower pan wouldn't rely on thin set to be water proof ? its gotta have a membrane of sorts

Kerdi is the membrane and thinset is used to adhere the pieces together. Thinset dries, magic happens, and then the shower is waterproof. Actually the magic I think deals with the science of interlocking crystal formed when the thinset cures and locks in the fleece. Only installed my own shower though so could be making all of this up.

All I know is my shower passed it's 24 hr. flood test with flying colors.

 

[Jeff H Young]

So basically you build a water proof pan with cement as being water proof.
gotta be some kind of membrane no?

 

[Travis K]

So basicaly you build a water proof pan with cement as being water proof.
gotta be some kind of membrane no?

The is a membrane. It's kerdi membrane. It's made by schluter. They're many companies that make similar products.
The membrane is water proof and then you overlap it at the seams when installing it. One uses thinset to to install and adhere the membrane itself and other surfaces. The thinset in the overlaps is very thin. When it dries it isn't supposed to allow water to seep past the seams.
Looking at the pics above i am claiming that the thinset was applied too thickly, and or it was too dry, and or the wrong type of thinsets. Shower pans tend to be done last and if someone is doing it their first time and is still using the same thinset that they started with earlier in the day, well... It can get dry.
As for the wrong thinset. As Jim wil surely chime in. Wrong can mean a few things. First and not that importantly, is that schluter only authorizes non modified thinsets or any of their schluter brand thinsets. It will void the warranty if you use modified thinset unless it's theirs.
That said, schlutet will spend thousands in court keeping them from paying out on a lawsuit. These things basically don't have a warranty. They will find a way to get out of it. So go ahead and use a modified thinset. I am a huge fan of customs versabond. It is crazy sticky and will pull the fleece off the kerdi after 24 hours of drying. I am also a huge fan of laticrete multimax for installing membranes. It doesn't have sand in it and it allowes for very tight seams.
But there's a warning. I and many others have had thinsets almost repel a membrane. I don't know why but some thinsets will not stick to the fleece. I am curious of which thinset was used in the above photos. It appears that the thinset did not stick to the fleece at all and this isn't a modified versus unmodified issue.
I checked John bridge and i didn't see a post fron the op. I would like to know what happened.

 

[Jeff H Young]

I'm sure its not just that schluter doesn't want to pay out claims . they want happy customers that have long lasting work. but if something does go wrong might be hard to prove. maybe he can get replacement product? and re build pan

 

[Jadnashua]

Schluter is a good company and will likely help...call them.

Kerdi has been around for over 30-years now, and is made and sold all over the world...it works when installed properly. Thinset doesn't technically 'stick' to Kerdi, but bonds to it because it flows around the fleece on the surface, and then cures, locking the thinset to it sort of like pouring liquid wax onto cloth...a bear to remove. It becomes waterproof on a seam only when you've mixed your thinset properly, applied it the designed depth, and then pressed the two pieces together and squeegeed out the excess thinset...the fleece from each layer interacts to repel water as it's hydrophobic only when the fleece layers are close enough together. If there's a gap, or the thinset is too thick, it can leak. If you use a cheap thinset with minimal cement in it, it can leak. If the overlap is not per design, water can wick further into the joint, but typically, goes no more than about 1/4", so the mandated minimum of 2" is overkill, but makes things safer.

 

[Jeff H Young]

relying on thinset for water proofing seems iffy. Gotta be overlap? and I guess it snaps together little squares interlocking? Cheap thinset leaks? If that's the case they should recommend specific products.
I think schluter is fairly proven even though I've never seen it in person, every system with showers and wet work , following procedures carefully is very important