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Schluter-KERDI system opinions?

1110d's picture

Schluter-KERDI system opinions? (post #207292)

Looking for feedback on the Schluter-KERDI shower liner systems.  Looking to use the product for the first time on a historic home where leaks would be totally unacceptable.  I see the system used a lot, but I'm not totally convinced on the water integrity of thinset.  Any instances of failure?  If so, what was the cause?

1110 (post #207292, reply #1 of 23)

The integrity of repelling / containing water is in the Schluter product, the thinset is merely a way to adhere it to the backer etc.

Same way the shower pan and integrated water directing system in a conventional shower/tub surround works.

Glazed tile is waterproof, it's the stuff between and behind that you need to worry about.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


But I thought the corner (post #207292, reply #2 of 23)

But I thought the corner pieces were lapped over the wall sheets?  If this is true, then the joint between the two layers is only as water resistant as the thinset.

It's a nice system and is (post #207292, reply #3 of 23)

It's a nice system and is waterproof. The down side is the cost. For a standard shower expect to spend $700 to $1000 on Schluter materials to make it happen. It takes practice to get corners and edges smooth so there are no bulges and the entire process takes a lot of time.

Florida Licensed Building Contractor, 50 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.

not so tuff (post #207292, reply #4 of 23)

I agree with the all the comments posted so far except for the one about the difficulty of installing the SK system. At the time I installed the three SK systems in my home over joist supported flooring, I was a semi-skilled DIY'er with little tile experience. The SK system came with an amazing dvd and also has videos you can view from their website. The corners were fairly easy to complete and the sheeting dries like fiberglass after you're done. There will be no leaks. I say give it a go! John

What???  You read the (post #207292, reply #5 of 23)

What???  You read the instructions???  You should be banned from the DIYer union!!

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

I'm also a believer in the SK (post #207292, reply #6 of 23)

I'm also a believer in the SK system, not because of using it myself, but I inspect and verify the flood tests that are required in our jurisdiction. This is done before anything else is installed over the Kerdi by filling the shower base up to the threshhold. I've never seen one leak yet, including some applications for site-built Roman baths.

Kerdi Shower (post #207292, reply #7 of 23)

I've used it twice--once with Schuluter's preformed styrofoam pan and once with a mud job floor. Follow the directions and you'll have a watertight shower. The process is straightforward and easy to understand. I especially like schluter's square drain. It's adjustable to make tile layout easier and the visible parts are made from stainless-steel so they won't corrode.


Patrick McCombe FHB Associate Editor

schluter kerdi (post #207292, reply #9 of 23)

I took the two day schluter hands on seminar and have installed the system a few times.  I feel confident that none of my showers will leak.  The company has invested a lot of money in education.  The system works.   No thinset is exposed to water.

schluter kerdi (post #207292, reply #21 of 23)

I took the Schluter seminar after doing my first installation. I wasted a lot of time that wouldn't have been necessary had I taken the training first. You get to make first time mistakes on Schluter's dime. Plus, the excellent training was free. They will even put you up in a hotel if you live more than 45 minutes from the training site. You can't go wrong.

Schluter shower system (post #207292, reply #10 of 23)

Hi, I have looked at the system but would not go any further than that, I have been installing and designing custom shower systems for over twelve years now and I am totally sold on the WEDI system, its is so easy to use and can be made to your custom size and shape. It is truly unbelievable how versatile it is, you can even make tubs, fountains, sinks, pools, etc.......with the wedi. They have a website and possiibly videos online. If not I am sure you can call and they can send a dvd.

You can actually install and tile the same day, it goes right onto the subfloor and the wedi wall boards go right onto studs. There is a small learning curve but once you understand the process you will be good to go. The problem maybe finding a dealer that sells Wedi close to you but dealers will usually ship. Where are you located?

Believe me with an older house there is going to be some movement and thinset does not have the ability to seal water........neither does grout.Having used the Wedi system for that long I have never had any problems and really can't believe the bathroom shows on hgtv and diy are not using the system......I see them using concrete, tar pape, concrete boardr and all kinds of things on there, unbelievable!! The wedi system is made from extruded foam with a cement/resin fibered covering, it is extemely heavy duty but also extremely light weight and easy to cut and design with. I have made niches and benches and decorative details with the wedi for the shower

The Wedi system has its own drain system which you put in right before setting the pre-sloped pan which is put down on the subfloor with thinset, the wall boards fit right into the routered edges of the pan which you fill with the special wedi caulking, the wall boards are then nailed into the studs with the wedi nails/screws and the heads are covered with the caulking, after the caulking is dry you can start tiling, it is definitely the way to go. If you need additional help or info I would be glad to answer any ??? Good luck and I hope you find the wedi system!!!


Dalene, Tile Art



Wedi sink unique tile
Wedi sink unique tile 1.49 MB
Tile Art Shower Wall
Tile Art Shower Wall 2.69 MB

I agree that WEDI is a super (post #207292, reply #11 of 23)

I agree that WEDI is a super awesome product!  After I did my bathroom with it, I was spamming threads left and right on the John Bridge forum regarding WEDI.


Nice work pictured, BTW!

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and hydroban? (post #207292, reply #12 of 23)

While I've not heard of Wedi and have read too many raves about Kerdi to question it, how do these systems compare to Hydroban or one of the other painted on water proofing systems?


You could consider WEDI a (post #207292, reply #22 of 23)

You could consider WEDI a pre-waterproofed cement board... all you have to do is seal the screws and seams. There are many ways to skin this cat. I liked WEDI because it also allowed a small measure of insulation. Being light was a huge plus too, as I'm a big baby about lifting things.
YAY!  I love WYSISYG editing!  And Spellcheck!


I have used Kerdi several (post #207292, reply #13 of 23)

I have used Kerdi several times.  The styrofoam drain and base system is excellent and easy to use.  However applying the Kerdi fabric is difficult and slow.  There is always a bulge on the overlap and if you try to minimize it then there isn't enough thinset to stick.  The floor corners are the worst because of all the overlapping.

I read about WEDI and decided to give it a try on my own bathroom.  Easy as pie!  The WEDI rep told me that once I used it I would never use anything else -- he's right.  More expensive than cement board but probably about the same or less than a Kerdi install.  Quick and easy.  Hard to find though.

I don't know if WEDI has a shower base system like Schluter (my install was a bathtub surround).

Schluter has a Kerdi board in Europe, but I haven't seen it in Canada yet.

kerdi (post #207292, reply #23 of 23)

Kerdi is available at Home depot in Vancouver.  I am sure they carry it in other branches too.

I have installed Kerdi in many bathrooms  (Wedi not available here to my knowledge). Corners and overlapping areas are easy if you use the right tools (read instructions). Had no callbacks in many years

Schluter-KERDI shower liner system (post #207292, reply #14 of 23)

My wife and I installed this shower when we built our house about five years ago.  This is our very first attemp at doing a shower and not only has there been no evidence of leaks in the basement below the shower, there has been no evidence of any moisture whatsoever.

3 showers done so far more to come (post #207292, reply #15 of 23)

All 3 previous showers leaked,  2 of them a 2nd floor MB the 3rd a 2nd bath tube surround. 

I agree to the post it's pricey, but! the advantages are worth it. Home owner wanted the shower relocated to the corner of the bathroom. I did a corner shower 54" x 54" with 2-3' arc windows. I used a 60" square shower Kerdi pan cut down to 54", since I had to relocate the shower I kept the section sub floor open to gain access to install the drain pipe up through the pan. Mounted Kerdi 7' high of the 9' tile. The remaining floor throught the MB I put Ditra down following installation instructions for a 2nd floor wood install.

2nd bath bath tube surround. Here I put up cement backer board. My concern was 24" center studs and didn't want the user to bounce off the wall flexing a drywall install. Cement doesn't flex, I thought a better backer for this reason. 

Another 2nd floor MB shower, with Kerdi pan...

Customer Service.  My helper picked up the wrong thin set that they recommened, after the debate, I handed them a cell phone and said convience me. Thier CS was great on explaining why you must use unmodified thin-set mortar and they had us read off the mix of the 2 different brands we had on hand to betermine the best one. I'm sure this varies by region on where you are located and what is available, so check with them.

This is great product, no holes going through the waterproof lining, valve and pipe seals and easy to install.

Some tips:
1. pre cut panels and layout all the pieces for a esay grab and install.
2. Mix thin set loose so it's easy to spread out and doesn't add a lot of bulk on the seams.
3. pre cut card board or wood piece to set on the floor to help protect liner during the tile install.

KERDI System by DIYer (post #207292, reply #16 of 23)

I, too, built a complete bathroom using the KERDI system. My wife layed out the design and selected all the components; large format Italian tiles, high end valves and trim, a 250 ib soaking tub, Toto toilet, 48" vanity and a 5 ft tower. In other words, it was all about style and style, in this case, meant "complicated installation at great expense".

The bathroom has been in service for 6 months and there are no leaks. Nor do I expect that there will be 20 years from now. I also expect that there will never be a problem with mold.

In general, installing the system was simple enough. I used a linear drain in the shower and large format tiles on the floor as well as on the walls. I reviewed the video and read the installation instructions. But I had a few problems.

The most difficult part of the installation was in the corners. Overlapping membranes glued with thinset bulged out the corners just enough to create problems with the installation of the tile. I discovered, however, that not all thinset is created equal and that the best thinset is the one you buy from the dealer who sells Kerdi products. Creamy thinset is best. 

So, if you use the Kerdi system, buy the best thinset for the job, pay very close attention to the corners to minimize bulge, triple the estimated installation time and spend lots of money and you will end up with a fabulous bathroom.

Remember though, that the Kerdi system is a German system and that means you better follow the directions precisely. Also remember that walls are expected to be flat, corners at 90 degrees, edges perfectly square and tiles perfectly cut. That's the German way. No room for sloppiness.

Schluter Kerdi system (post #207292, reply #17 of 23)

We are not contractors but fairly experienced DIY'ers and we used this system to surround a walk in shower in an old circa 1870 house. It took a while and it wasn't easy and it used way more thinset than we expected, it really worked well. We used their system to create the pan as well - graded foam strips that go in the mortar to slant towards the drain. Our is a walk in shower without any curb at all and no water escapes into the main room at all when we shower. We have a shower curtain across the doorway that just clears the floor and no water leaks out. We are very pleased but I agree with the cost factor - it's not cheap.

do you have any photos of (post #207292, reply #19 of 23)

do you have any photos of your project?

I used it and liked it well (post #207292, reply #18 of 23)

I used it and liked it well enough. 

I read the comment you had about the lapped pieces, but I think your concern is overblown. If you lap pieces the water has to move sideways to get into the substrate. Thinset *could* wick it sideways, but the amount would likely be miniscule...

That said, I always go a little overboard... I used redguard over the lapped sections : D It seems like that would make it impossible for water to penetrate. The Redguard fumes did bother me, so I recommend wearing a respirator while applying it.