I am building a walk in shower. The Sheetrock is up, time to start putting up the Kerdi. In demo video, they band all corners and lay sheets cut to each wall. Is there any reason I can't use single sheets to go around corners? I understand placing each sheet will be a bit more work, but, it would seem to me that fewer seams is better and also saves a little material.

I was wondering if maybe it had to do with the thin set setting up very quickly, allowing little time to fuss with the kerdi. Or maybe Schluter likes selling Kerdi Band!

Install Answers for Kerdi Membrane - TCNA and TTMAC do NOT allow drywall in a shower I have deleted all my posts showcasing Kerdi, Ditra and the like from Schluter Systems. I have stopped using these products and do not recommend them now to my online clients, my local customers. You will not see photos here going forward. No one asked me to delete these photos.

No one told me to delete them. I feel these products from Schluter come with far to many restrictions and that the testing of the products leaves lots to be desired. It was my testing of the niches and resulting phone call to review my findings that finalized my decision to switch to a more premium waterproofing approach a quit using Schluter's products all together.

Oct 28, 2015. Schluter Kerdi Shower Systems Assembly With Prefabricated Tray and Curb. Materials needed for installation: KERDI-DRAIN, which includes the KERDI-KERECK-F pre-formed corners; KERDI waterproofing membrane; KERDI-BAND waterproofing strip; KERDI-SHOWER-ST prefabricated tray.

If you need help with a Kerdi Question email Dale at - this is Schluter's top tech. Remember that Jadnashua (Jim) here on Terry's forum is not in this business and by my account works to privately promote Schluter and the John Bridge Tile Forum. Pete, I don't mean to 'pile on,' but. NO GYPSUM in the shower! Not even the green or blue stuff!

Yea, I know, various vendors make various claims. Read the fine print. There's a lot of 'maybes' in there.

Murphy's Law will ensure that something goes wrong. I'm not a plumber; I do electric work.

Several of my customers are property-management firms, so I get to see plenty of remodel work. I have yet to see a any gypsum product, any tile job, survive. So, when I do my bath, it will be cement board 100%, even on the ceiling. If nothing else, the cement board won't dent when you hit it with a mop handle. No paper or glue to feed mold, either. Skim coat it with real plaster, and it's as waterproof as steel plate.

FWIW, my walls are getting covered with FRP (fiberglass reinforced plastic) sheeting. Absolutely waterproof, with very few seams - and none of the seams are horizontal. It's that pebbly stuff you see in commercial kitchens and public restrooms. Maybe I'm over-doing it, but the difference in materials cost is not that much.

It amazes me that folks will spend a fortune on getting just the 'right tile,' yet compromise on the basic structure. Kerdi is a waterproof membrane. When it is installed properly, once you protect it with tile, no moisture penetrates it. John is a belt and suspender kind of person. Being in a business where you never want callbacks, it has some merit if people are willing to pay for it.

Schluter has paid for an independent testing of Kerdi membrane installed over drywall and it passes all industry specifications for moisture protections IF IT IS INSTALLED PROPERLY. In my 60+ years, I've never had a belt or suspender fail, and have never worn both. You either believe the manufacturer and the testing, or you don't.

They do not force you to use drywall, they also list other acceptable materials, which includes cbu. You use what you feel comfortable with and local regulations require.

There are thousands and thousands of Kerdi showers in use today applied over drywall that are as dry as the day they were built. If you have a leak, it's either because of poor workmanship or an accidental puncture that occurred after testing and before tile. A leak would require fixing whether it was cbu behind it or drywall whether it was through the membrane or from a plumbing leak behind it. If you don't believe a single layer waterproofer is sufficient, then you'd want cbu on your walls and especially next to your windows in all the rooms of your house, or make the walls poured concrete.

A house exposed to rain driver gale and hurricane force winds is a much more hostile environment than a shower. I trust my shingles and paint on the outside of the house to protect the interior walls as I do Kerdi to protect my shower. Feel free to augment it if it makes you feel better. I've got the certification test document somewhere, but you can find a copy on-line if you look.

Since the test is only valid for a few years, it gets repeated, and has always passed. Most local inspectors will allow installation to the manufacturer's instructions with that certification.

Some won't, and then you do what you have to should you want to use that material. There are lots of choices, pick one you're comfortable with, but installed properly per the manufacturer's instructions, they all work. Some give you more margin for error than others, but if you trust your workmanship and workplace environment to not compromise it, that's somewhat irrelevant. FWIW, in the USA (don't know what the duty is to Canada), you can pick up Kerdi membrane for around $1.75/sq ft fairly easily. Many places offer free ground shipping. Also, if you believe the websites selling it, list price is in the order of $1.91/sqft. Canada can have some high tariffs on things, so your pricing could vary considerably as well as shipping.

OK, Jad, I won't debate your religion with you. 'IF' is the biggest word in the language. Heck, I'd win the lotto IF I pick the right numbers. IF the Queen had balls, she'd be King. So go ahead, get by with the minimum possible. I'm confident you also wear Wal-Mart $8 sneakers and drive a Yugo.

After all, they meet all the same regulations as the expensive name brands, so they must be just as good. While you're fumbling through all that documentation. I seem to recall seeing somewhere that there were model codes that banned drywall and greenboard from 'wet' areas, like showers- no matter what was over them. You might want to be sure. And get the permit and inspection as well.

Everything I need to fix in my house is the direct result of someone being 'smarter' than the rule book. Click to expand. Personally, I've installed several, seen many more installed, and in contact with people that have installed many hundreds. Some argue that paid testing is biased.

But, if you believe that, then you'd ignore any UL, CSA, IAMPCO, or other testing that is paid for by the manufacturer. I don't put storm windows over my windows, or an awning over my roof, to give things a second waterproofing layer.I believe, that properly installed, they can do their designed job, as I do believe Kerdi works as designed. I don't care what you use, if it is not installed properly, you can have problems. I happen to drive a BMW, but that should be irrelevant to the issue. I'm not adverse to spending more for better things, but at some point, more doesn't buy you anything except a smaller bank account, personal preferences aside.

Wow, looks like my thread came back to life in a big way this past week. Here is where I stand.

My shower is drywalled, ready for the kerdi. Haven't hung a single piece yet. Have an expensive roll of it sitting here waiting. I bought the entire roll with the understanding that I can return any I don't use. My gut feeling, even as I was hanging the drywall was that it was a bad idea, but the kerdi dealer was adamant that drywall is the way to go.

I now realize that maybe this is a marketing strategy. Kind of their way of saying their product is infalible. So, do I rip out 50 bucks worth of drywall to avoid later ripping out a thousand bucks worth of tile/kerdi or do I continue taking great care to do it right? I am kind of leaning towards moving on and just making sure I do it right.

And crossing my fingers!!!! So, did I read right that a coat of drywall primer would be a good idea?

BTW, the mortar I have is Versabond fortified thinset. I bought it from Ace hardware.

Recommendations on primer or anything else are greatly appreciated. Thanks for all your help. You either believe the testing and the manufacturer that Kerdi, properly installed, is waterproof, or you don't. Or, you don't trust your ability to do it right.

If it is waterproof, as long as what's behind it is stable and is recognized to be able to hold and bond with thinset for a good seal, it's good (there are millions of tile installed on drywall outside of a shower, so drywall is known to hold tile and thinset well as it will hold onto Kerdi). If you don't believe this, don't use it! If you don't have confidence in the manufacturer, don't use it. If you don't trust yourself that you can do it, don't do it! Versabond is a modified thinset (lightly modified, but still modified). There's nothing wrong with using cbu, or adding other products that are known to be compatible on top of it to give you extra margin except for the costs (and starting with something else may work as well and be less if you're going to combine products). If you feel that extra margin is worthwhile, go for it, it's your house, may make you sleep better.

Using a modified thinset voids your warranty, as Schluter specifies only the use of an unmodified when using this material. A worst case test will be the flood test. A shower does not normally have standing water in it, and if it does because of a bad drain or something similar, it typically doesn't stay there for the common 24-hours or more a flood test checks. Very little moisture normally gets below the tile in a normal shower, but it still needs to be managed, and if not, can accumulate and cause problems. With the slope on the pan, there should be no pooling of any possible moisture underneath the tile on top of the membrane. The sheet material is waterproof, a proper 2' minimum seam may wick a little water, but not beyond the full width, unless you have too much thinset in there (this is where the technique is important). But, even then, if you have the proper slope to things, there is no hydrostatic pressure to push water into that seam - the only time it would happen is during the flood test.

Kerdi has been around for a long time, many showers installed with it. Most local inspectors will look at the certification from an independent lab and the manufacturer's installation instructions and, if those are followed accept it. If yours doesn't don't fight them, you'll lose either time or money and it's not worth the aggravation. If you take the time to read the certification document I'm linking to, you will see that it was both tested and passed with the use of drywall in a shower. It also passed with other backer materials.

Any of those work, your choice, since the certification covers all. The manufacturer indicates in their installation instructions their preference for drywall as the easier, less costly installation media. You are not required to use it, but if installed per the instructions, it is fine.

We’ve already talked about and, and now the moment you’ve all been waiting for How to install Schluter Kerdi! Ok, really quickly, for those of you who have no idea what I’m talking about Schluter Kerdi is the orange fabric looking stuff you see rolled up in the picture above. It’s soft and felt-like but also completely waterproof. It’s made by a German company called and cool guys like and use their products. You may have heard of Schluter Ditra, it’s also orange, but more of a plasticy honeycomb structure, and is used on floors, under tile.

I’ll show you today how to apply Kerdi membrane, it’s kind of like applying wallpaper, then *poof* you’ve got an instantly waterproofed shower! Remember this was my very first attempt at building a shower or using Schluter Kerdi, but it sure did turn out awesome.

My point is that if I can do it, so can you! How to Install Shluter Kerdi in a Shower 1. Plan out and cut the Kerdi Do yourself a favor and read through all these steps before you cut a single piece of Kerdi. You want to keep your pieces as big as possible, and you want to plan out your seams. I was able to do the entire shower with only one roll of Kerdi. At $100 per roll, it’s not something you want to mess around with.

I cut pieces for the two side walls first. The width of the wall was smaller than the width of the Kerdi, so there was enough left to fold it over to the other wall. When it comes to Kerdi, there are two options for the seams: (1) Seams can be constructed by overlapping the edges of KERDI by 2″. (2) Alternatively, you can butt pieces of Kerdi against each other and cover the seam with KERDI-BAND.

I decided to overlap the Kerdi. Next I cut the piece for the floor, it over hung the shower curb, which was perfect. It’s best to use one piece of Kerdi to cover the curb, rather than create seams. Mix unmodified thinset mortar to a fairly fluid consistency If you watch the Schluter videos, you’ll hear the guy say these words over and over.

I mixed 1/3 of the 50 lb bag to start and modified the water accordingly. Instead of a 5-gallon bucket, I use gallon water ice containers left over from a home owners association party. They would have just been tossed in the trash, so I don’t give too much thought to using them once or twice, then throwing them out. Cleaning thinset off your tools is a pain in the butt.

Apply thinset The bummer about working with unmodified thinset is that it dries much faster than modified thinset, so you don’t have as much time to work with it. So don’t screw around. Figure out how much of an area you can complete in about 20 minutes. This is why I mixed only 1/3 of the 50 lb. This was my first time doing something like this and I knew it would take me 20 minutes just to get the hang of it.

I started on the left side wall first. This is the Schluter Kerdi hanging out waiting to be installed. Wet the wall down with a damp sponge first.

Cement board soaks up water like a beast, so be generous. (Remember it’s not necessary to use cement board, you can install Kerdi over drywall.

I discussed this in.) Then spread a smooth layer of thinset with the flat side of the trowel. I split the wall into top half and bottom half and wet down and applied thinset to only the top half first. Once the area is covered in thinset, use the 3/16″ notched side of the trowel to add additional thinset, raking trowel marks into it as you go. I don’t have any pictures of this part because I was taking a video of the process, so I suggest watching that.

Attach Kerdi to the walls The goal is to embed the Kerdi into the thinset, so the first thing to do is lay the Kerdi in place, then pat it into the thinset with your hands. Make sure the Kerdi is positioned exactly how you want it.

I planned to have 2″ of the Kerdi membrane cover the adjacent wall. This meant I would not have to use in this corner and I was all for one less step. Of course I needed to apply thinset to this 2″ portion of the adjoining wall to embed the membrane into. Once the Kerdi is in place, use a drywall knife (or flat side of a trowel) to push the Kerdi into the thinset using a “smoothing” motion. It’s similar to applying wallpaper, you start in the middle and push the excess thinset out to the sides. Make sure the corners are nice and crisp. Now do the same with the lower half of the wall.

I had minimal cutting around the shower curb, which was easily handled with a utility knife. After the left wall was complete, I did the wall on the right side, followed by the middle portion of the middle wall.

I can’t remember my reasoning exactly, I guess it was because the top section was going to be pieced together with two smaller sheets. But it looks like that middle section was pieced together as well. Use full pieces if your worried about it. I made sure there was a 2″ overlap on every seam, so I know I’m good. I was on a mission to only use one roll of the Schluter Kerdi. Mission accomplished.

A few action shots. A big thank you to my 7-year-old daughter for these. All the walls complete. Note the bottom of the middle wall, 2″ of Kerdi is on the shower floor. Again, no will be necessary at this seam. Just to be clear, the Kerdi membrane on the center wall stops at the corner, not 2″ from the corner. So there is a 2″ double layer of Kerdi running up both sides of the middle wall.

This is a requirement because it is a seam. Apply thinset and Kerdi to the shower floor So you will be a pro at this point, but that’s good because the shower floor is the trickiest part because of all the corners (step 6). So there are four walls attached to the shower floor, if you include the inside of the shower curb, which we are so get on board with it. And you now know, wherever two pieces of Kerdi meet (the seam) you need to have a 2″ overlap. So be meticulous in your planning (step 1) and make sure you consider all the seams.

Alternatively, you could just cover the seams with, which is half the thickness of the Kerdi membrane by the way. Looney Tunes Photo Print Studio there. • Back wall – Kerdi from the wall overlaps the floor 2″ and will be under the Kerdi on the floor • Left wall – Kerdi on the shower floor will overlap and come 2′ up the wall • Right wall – same as left • Shower curb – there won’t be a seam because one sheet of Kerdi will cover the floor and the curb Um, so yeah, maybe this isn’t a project for dumb girls DIY because there’s a lot of thought and visualizing involved.

But you’re smart, so don’t worry, you’ve got this. Now that that’s figured out, apply the thinset and Kerdi the same way as above. (1) Wet the floor, (2) apply a smooth layer of unmodified thinset mortar, (3) spread additional thinset with 3/16″ notched trowel, (4) embed the Kerdi with drywall finishing knife, start in the middle and push thinset to the edges. Wrapping the Kerdi over the curb was challenging because it was hard to get the thinset to push up and over the curb. It wanted to go back down and under the Kerdi on the floor instead. But it all worked out fine. Cover all corners Preformed waterproof corners come with either the or Kerdi-Drain.

You need to add these to the corners because there are multiple seams in these locations. There are different preformed corners for inside corners and outside corners, so make sure you have everything all figured out before you apply any thinset. An outside corner is used where the shower curb meets the wall. Apply seals around shower components Both a pipe seal and mixing valve seal come with either the.

They’re like a combination Kerdi Band with a plastic ring that goes around the fixture. I was only able to use the pipe seal because the other did not fit.

But that’s okay, I tested to make sure the cover will protect the opening. To apply the valve seal, just add thinset to the Kerdi that is on the wall, slide the pipe seal over the pipe and embed the membrane into the thinset. Let the thinset dry This is the easiest step! Give it a good day to dry. Perform a water test They make a handy just for this purpose. It was really annoying to fill the shower pan with water because we don’t have a sink in the bathroom yet, but hopefully that won’t be the case for you. Robert Randolph Jr. Fill it a few inches high, then mark the height along the wall.

Come back 24 hours later and see if the water is still at your mark. Once I got the drain plug figured out we were good to go! I didn’t lose any water over night. So that concludes the “building” part of the shower. Mine sat like this all summer while I hung out at the beach with my kiddos. I have since tiled and grouted the floor (with, God help me!) and I am currently finishing up the wall tile. But I feel like the hard part is behind me because the shower building is what intimidates most people.

If you’ve read this far, you seem pretty determined, so I’m confident you can make it happen. Just maybe try not to take as many breaks as I have. I can’t wait to use my shower, even though this is just the guest bathroom. Now on to tiling! BETWEEN POSTS YOU CAN CATCH ME HERE: / / / / I’m linking this post up here.