WATERPROOFING A MASSIVE SHOWER!!!---Part 1: Installing Kerdi Membrane

In this video we install Schluter Kerdi waterproofing membrane in a shower. This shower is massive...almost 10' long by 4' wide. I show in this video what type of adhesive thinset mortar to use, what trowel to use, and special techniques to avoid thinset build up. This shower has a ditra-heat floor and bench plus a double line drain set up. To see all of the other steps in this shower build, please watch the other videos in this playlist titles "May 2020 Bathroom Remodel". Here is the link: • May 2020 Bathroom Remodel
Find me on instagram @tilecoach and send me an email if you have a really bad shower or need help. I cannot guarantee I will be able to respond but I will do my best.

[@TileCoach]

I forgot to mention this is part 1 of 2 videos. As you can see, there is no band or 8+9. On Friday I will be uploading the part 2, where I use Ardex 8+9 to install the kerdi band.

[@armorer1984]

I'm anxious to see the Ardex 8+9 used as a bonding agent for the Kerdi band. Awesome work!

[@brent9129]

Gotta try Marshalltown cement float for laying membrane. Allows you to put a lot of force and really press those bubbles out. Plus blunt edges make it safe and great for corners

[@jayvee5398]

Great job tile coach! Idk if you do a lot of upholstery or wrapping cars but checking out a few upholstery/ wrap videos. I'tll help with laying those waterproof sheets in the future. They pretty much start at a corner or edge and work bubbles out as they move along instead of lay the whole sheet down.

[@nickcary6145]

I use a plastic wallpaper trowel works awesome no sharp edges. Very easy to get good corners and easy to clean up

[@bearridgeconstructionllc1249]

Curious why Schluter says Ditra Heat mats or sheets are waterproof already minus any seams but you along with some others also install kerdi membrane over the shower pan... Is schluter wrong about the ditra heat being waterproof as is?

[@LandbergTileTV]

"This Stuff Feels Good" I say the same with working with good thinny.. Good stuff Isaac!

[@jeremyroberts4568]

Just wanted to add that with both schluter workshops I have done I have learned it is best to use unmodified thinset behimd membrane and on surface of membrane to set tile. I use mapaei kerabond unmodified or the actual schluter all set thinset. Just my input. Love your videos man great job.

[@bufunga]

I thought that too, which is why i5 just peels off?

[@elcoyotecojodeldesierto2300]

You are right sir

[@marcusaydelott]

I like to use my resin float to embed my membranes. I don’t have to worry about nicking the membrane and I can get good pressure to squeeze the thinset out.

[@OneWheelLess]

Great video :) I thought that wrap seemed ambitious! I’ve had it work, but it seems more trouble than it’s worth. I usually install that top sheet with a 2-2 1/2 overlap onto the bench then use 2nd piece to wrap the bench. I really like to use paramedic shears to cut all my kerdi. They hold up forever and the tip won’t puncture the membrane or things like that heat cable 👍

[@hollywoodstarfish]

Great great work my brotha 🤙🏼 but that sheet of kirdy installed upside down is driving me crazy 😂 just aesthetics but I’m the guy who has all the durock sheets with the words going one way. That’s going to be an awesome shower!!! Love your videos 😎 🤙🏼

[@keithscofield4583]

When skimming walls you can treat them like a drywall finisher would on a level 5 finish and get big skim blades to make them smooth and strait. Also take the thin set out of the bucket and into a mud pan and use a 12 inch mud knife to get it on the wall. This will speed up floating walls by atleast 75%

[@tomhman6441]

One of your best yet.step by step is the only way to learn.all good.

[@Oliversmith17]

Proper tradesmen love your videos! All the best from England

[@JLT2342]

Wow, Thanks so much for showing this. That is what I doubt the water with leak through the thin set layer that acting like adhesive between two layer of waterproof membranes. I think couple months ago I asked Sal about this and his answer was "no way".

[@franksalituri5988]

Any chance you can include how you flood test for the inspection, would be great. Thanks

[@williammingey961]

I'm with you man about the right feel of thinset on your trowel .u just know that trowel and thinset and you become one .not too loose not too thick .

[@ABlueDahlia]

Geez who in the world needs/paid for a huge shower like this.. wowza.

[@Mike-Minion]

i love the quality of work you do. I'm just not sold on the kerdi yet.

[@Rustyshackleford752]

Trick to make kerdi 100% is to use red guard or some other paintable waterproofing membrane to go over the seams, but without that, I don’t trust it completely either

[@justinofboulder]

I concur! Though I have only used it maybe 8-10 times and only once over a heated shower floor. The schluter linear drains are my least favorite part....

[@robbob4872]

@@Rustyshackleford752 red guard by itself is better than kerdi

[@Robinio8989]

Sick how neat you can work, makes the difference between diy and pro:)

[@JW-pj1zd]

I agree the ardex 5 is funny like that with any type of membrane. I also wondered why it does that. I am currently using exactly what you are using. That's what seems to work the best . Ultra 2 is a good product for the membrane.

[@davethompson16]

I asked the local schluter rep and he said they void the warranty if you use any other modified thin set then theirs.

[@Aepek]

26:11 Is that the Mapei Ultraflex LHT mortar, or the Mapei Ultraflex LHT SG(am assuming it’s Mapei)? Can really see the mortar standing up well for ya & that really does help when using the Kerdi Ditra & all those lugs to get around etc... Also nice to see you guys take your time with this stage, cuz rushing this process doesn’t end too well. This bathroom is going to be amazing when complete. With each video, get more & more excited (yes, can see it in my head....like I know you & others can); but there’s nothing like “seeing” the completed job in person & having “that feeling”👍🏻 You did mention a grout float, & I’ve done that at times on the initial set, than go back over with flat trowel to get those bubbles out😉 Very impressed didn’t get anything on your clothes, good job. Sometimes no matter how careful I am, the stuff gets on me, & swear it’s gotta be magic, lol. Have a good one ✌🏼

[@FVPS904]

Kerdi band and sheet material is totally different, I learned a long time ago that sheet material will never act like band when it comes to corners

[@disel1983va]

such a master I’m enjoy looking your video a lot of good information

[@aaronpage1822]

Props to you for being able to do your job in nice clothes and not get any thin set on your pants.

[@mjremy2605]

Wow, you did a really great job! Such an artist. MAPEI is an Italian company, Schluter Kerdi is a German product. Both are excellent! I was curious about a couple of things: 1. MAPEI ultraflex thinset mortar has polymer mixed in it. Is this any different from regular thinset mortar + polymer added? I will always use polymer instead of water as it rubberizes the mortar so it does not crack easily in earthquakes, ground settling, or RV motorhome installs. It holds up to vibrations well. Polymer in grout also seals everything nicely and no need for a sealer top coat. Can you use the same Ultraflex mortar for tiling as well? 2. Why not use Kerdiboard which has both the backer board + waterproof membrane in one package? It would save on labor having to thinset coat twice - once for the membrane install, then again for the tile install on top of that. Plus Hardibacker board and all the cement boards do not hold up to moisture and are very heavy. Seems to make no sense unless it is a cost savings.

[@user-lc2ug1hb1q]

I didn't notice what you did in the corners. Do you always end a sheet in the corner and then add a strip or do you wrap around the corner?

[@waldemarpalomo]

What motivated me to go for my license is I used to work for guys that had no license and they never paid on time take up to 2 to 3 weeks for them to pay

[@CharlesJamesdesign]

why at 24:47 did this video take a turn, for the kinky side!! Haha great video love brotha

[@jschaefer8549]

Looking at the schluter site they say all you need to do to waterproof the ditra heat is use kerdi band on the joints. The ditra heat is already waterproof. Is the extra kerdi sheet really necessary ? Thanks for great videos !

[@bearridgeconstructionllc1249]

Exactly my thoughts. Schluter claims Ditra Heat is waterproof minus the joints

[@jon22988]

you say you are using Mapei Ultraflex 2. Isn't this a polymer based thinset and doesn't Schluter say to use a unmodified thinset?

[@mikesmego1510]

I thought so too..but schluter all set is modified so..

[@devinmccauley7783]

Hmm. Kerri says to use Non modded mortar mix. Can you elaborate why you chose this mortar? It looks much easier to work with. Thanks!

[@gregsanden3691]

Kirdi membrane for walls is a hassle quit useing it years ago , bubbles , egdes dont bond , red guard much easier and water proofs just as good if not much better , Kirdi floor systems and pans though are great systems .

[@justinwalsh5664]

That looks great coach!!!

[@EricNeilson_]

I thought your tests half-confirmed that the Kerdi membrane wasn't waterproof under 'relative' extreme testing (continuous water, or standing water over a week). Great work though!

[@draconicwindbane2056]

Gotta back your products brotha

[@maxplant6926]

Yeah I thought this too!?

[@TileCoach]

See pinned comment above, this is part 1 of 2 videos.

[@tophatt5706]

Easier, cheaper, and faster to shim studs before drywall. Plus you can waterproof same day.

[@butrintiny3201]

I do construction for living and I can say really good job(Can’t trust a lot foam boards and I do same as you are doing,cement boards-membrane on top..). My only concern is the fact that I can’t trust 100% the membrane(especially if there will be any leak from the ceiling or from behind of cement boards-humidity may weaken the membrane...just saying). What’s the best thin-set you have used for waterproof membrane installation?

[@mwoolston100]

I updated my shower put in a mud pan with linear drain. I waterproofed it with kerdi membrane. Today I did a flood test and it did not leak but water wicked up about 3 inches. My question is can I put hydroban liquid membrane on the pan to keep it from wicking? Kerdi told me I don’t need to but I want to stop the wicking. Thanks, Mark

[@daroldw4606]

Can you float the floor pad first and let it cure and then go back with the Kirdi membrane?

[@JoeySchalger]

Great video. I would really like to see what you all did with the drains in that size shower. Foam Pans or drypack?

[@a.dejesus792]

Great vid. Great info. Thanks.

[@GilBatesLovesyou]

One thing I thought of... What about grind down and round off the corners of a taping knife, so the knife won't poke the Kerdi?

[@briankowald6465]

Since this was three years ago, would you still use Sluter Kerdi membrane today?

[@coreybond9656]

Just wondering why you would put kerdi over the Ditra in the shower area? Is it because of the heated floor? I know in ontario canada I dont think we are allowed to put heated cables in the shower. Definitely great work! Love watching the videos.

[@Phiire]

I love UltraFlex II..sadly its been getting discontinued at most of the stores here in AZ.

[@juleswere5811]

Hi there, any reason why you guys put a layer of kerdi membrane over the ditra heat? From what I've seen on the Schluter website, you can just put kerdi bands over the joins in the ditra and tile straight on top...

[@trungphan2550]

Can I install the kerbi waterproof membrane over the regular drywall or do I need to install backer board or kerbi board before adding the kerbi water proof membrane? Thank you!

[@bufunga]

I think your supposed to use Unmodified thinset for this membrane

[@johnandrew9934]

Do you ever worry about the water proofing being right under the tile if you ever have to take a tile out and replace it?

[@brainhub1281]

Shouldn't the horizontal seams overlap so that the one "up the stream" goes over the lower portion? In other words, if you use the tape, you need to stick upper half of it under the layer above. Similar to how roof shingles are arranged. don't see this in this video. Thank you

[@davethompson16]

That is the same issue I deal with. Schluter says no but it doesn’t make sense.

[@nahumromero7826]

Is ultra 2 modified or unmodified? I think I read somewhere that it requires unmodified. Just asking if ultra 2 can replace schleuter all set! Thanks "D love your videos and great info

[@TileCoach]

Schluter All-Set is modified. Go figure.

[@alexcummins2722]

nice

[@hsiehkanusea]

The electrician has those light switches/rockers inside the wet area?

[@Peter-fg7rd]

why not use denshield behind motar bed and avoid the kerdi ?

[@jtltet]

If you have the Ditra on the floor, why would you need to put the sheet membrane over top of it?

[@garohachigian339]

Hey bro two quick questions. First can you double up on the membrane on the shower pan if necessary? Also I've seen you use a few different waterproofing methods on top of the membrane. What's your current favorite?

[@kennethlemke9826]

Crazy big job and lots of labor…looking good. Not for a DIY person. Wouldn’t red guard be easier on the walls. Using cloth on the corners and screws.

[@suave47]

Nice install. Question though. I do alot.of what u do on my installs. But I have had great success with the ardex products under and over my schluter products. Could b the climate. I install in mid to northern Canada so a way diffrent climate. Lately I prefer the uzin cx30 for over and under schluter systems. Strong bond, easy to work with (creamy) and no slump. Also dries very fast when between 2 non porous products. And that's my question to u. What r your thoughts on polymer modified and non modified mortars. Ivw always been told that ultraflex 2, being modified, (and.possivly the lht mortar) needs a porous product to dry into. Thus not allowed b/t ditra and kerrdi. Thoughts???

[@tjdonald9084]

It looks like your float is about 1/2” thicker or so than your drywall..How will you cap this in the end to hide to mortar bed?

[@Rustyshackleford752]

I would like to learn floating walls, I’ve been at it for 21 years now and hadn’t had to float walls other than shower pan repairs on older home...problem is, I work in generally new construction and these builders I work around don’t like to pay for stuff like that. Hell, I used to wet shim but due to time and money constraints, I’ve just been struggling with the shitty framers I have to work behind

[@Aaron86v]

I'm right there with you bro. I'm 27 and just started doing my own thing after working with my dad for 7 years. The framers are horrendous. A lot of times you are forced to do things not exactly the right way because there's no other option. The builder isn't gonna pay me to fix any walls so im stuck with it. Most times for me i cannot trowel my thinset onto a wall ever because a wall is so off. So i have to build out with thinset. I know you're not really supposed to do that with regular thinset, but the builder wont pay for medium bed either so idk man. Just working with what i got and what im allowed to do, kinda sucks.

[@aaronpage1822]

@@Aaron86v sounds like you need to go with a different builder that allows you to do your job correctly

[@Aaron86v]

@@aaronpage1822 That’s one of the big problems down here in south Texas... There’s lots of cheap work, so basically no one wants to pay more even if it’s a proper job. Most of them don’t even know what a proper job is.

[@JustinMentionedIt]

@@Aaron86v that’s what I callin fkn up on purpose and it sucks to have to do that

[@Aaron86v]

​@@JustinMentionedIt I know im still doing a better job than anyone else could do for the price and job, so i don't lose sleep over it. Always gonna do my best regardless even if the builder doesn't care as much.

[@Jkswartzell]

On the Ditra, do you need to cover with membrane if you aren’t doing the heated floor?

[@keithschwaiger9951]

Can you put Detra heat, under foam shower pan

[@21dazey21]

How does the plumber know where to set the valves? Do you just tell him a half inch and that’s what you shoot for when you float the walls. he has a little bit of wiggle room with the valves but not much.

[@JustinMentionedIt]

Is that bench foam or is that a dang inch in mortar bed !?

[@carlosmorales-yc2yn]

Hello Mr. Tile Coach. I’m a big fan of your work. I have a question about your inside shower floor. Was the wood floor NOT Hot Mobbed which made you add the Vapor Retarded Membrane on top of the Uncoupling Membrane for waterproof ? Or was it Hot Mobbed but you wanted to add the Vapor Retardant Membrane on top of the Uncoupling Membrane?

[@franksalituri5988]

BTW! Beast of a shower Bro!

[@ronsirolli8533]

Mike how are you changing for all this work I am in New Jersey’s do you charge sf for labor plus materials

[@tjdonald9084]

First comment! LETS GO TILE COACH!!

[@MrTooTechnical]

great vid. more stabila

[@jeremyroberts4568]

And another input for people that may not know is schluter warranties lifetime if you use there thinset and 10 year warranty with the proper premium thin set like mapaei.

[@robbob4872]

ha ha, they would never pay ..

[@hollywoodstarfish]

I love using schluter all set but it’s crazy expensive 💸

[@zmonty09]

but hate being the next guy to tear out mortar bed

[@FearbeloW]

It does shrink!! I will not use x5 with any heat mats what so ever

[@mericanwit]

So... the Marpei thinset is the way to go with Kerdi even on the 2” overlap?

[@radodrill]

What are the advantages of using the Kerdi membrane vs Ardex 8+9 or Redguard/Hydro Ban on the walls?

[@armorer1984]

My thought is that the Kerdi would act like an isolation membrane when the structure moves. I know the liquid membranes do have some flexing capabilities, however they are still bonded to the substrate and have limited ability to decouple from small structural movement. I think that's where the thinset/fleece have a little better ability to flex and move. The weakness is the seams where thinset can wick water, which is where the liquids come into play. That's my thinking, anyway.

[@florindeconde7952]

Hello man! Do u have a nick name? U should be called Golden Hands! Thumbs up!

[@andymarinshaw911]

Full disclosure, I'm a newbie to this so dont scorch me if this is a dumb question. I'm confused about the use of kerdi on floated walls. Why do this extra work?

[@MrThunderbumper]

It’s about levelness of the wall. Simply adding kerdi-board to the substrate won’t fix problems with the wall being out of plumb. Floating the wall fixes this issue, and then the kerdi membrane provides level 1 of 2 waterproofing (Issac prefers the one-two punch of kerdi membrane and Ardex 8+9 or Laticrete’s hydroban for waterproofing the shower.) Hope this helps.

[@eamonnmcstravick2721]

Instead of wetting the wall Why not use PVA bonding Seals it up and helps the adesive

[@GilBatesLovesyou]

Weirdly in USA we actually don't even have plain "PVA" adhesive. The closest you can buy is Quikrete Concrete bonding adhesive, all branded/patent stuff for companies to make more cash. To be fair, too, water is also free and should work fine.

[@tonygoshive785]

I have a quick question, over here in the uk. We called thinset, tile adhesive. My question is what kind of tile adhesive is suitable for Kerdi membrane? Struggling to find the right adhesive for this purpose, as the most common bag stuff we have are usually rapid set with only 30 mins working time. It would not be enough working time?

[@devony5813]

You can buy the mapei theyre using here from tilegiant and other online retailers, the best,easiest to use and most cost effective here in the uk is topps tiles own brand with a trade account slow set flexible in grey or white, the bal grouts and silicones are also the best we can get, the actual tiles are overpriced through

[@tonygoshive785]

Devon y thank you you are a life saver! Didn’t know topps tiles do a slow set adhesive.

[@SuperSteven0808]

Can I use durock cement board for membrane?

[@waldemarpalomo]

There is questions about membranes and ansi A 108.1 A118.1 A136.1

[@mericanwit]

Bruh! Wifey gonna go nuts having them dirty clothes in the washing machine😝

[@davidwetzel4340]

Did you try ARDEX X 77?

[@dw1986jr]

Anyone ever tried the roll on membrane one the bottom band and then gone back over with the mat (detria)?

[@robwalker8530]

I thought you only apply Kerdi to the seams of the ditra heat?

[@OneWheelLess]

Not in a shower, you want a continuous membrane

[@robwalker8530]

Yes, I should have checked the installation handbook before commenting, it is on page 11.

[@mallorymoore987]

I'm trying to learn as much as I can from all your videos. You're freaking awesome. but, teach your camera men to hold the damn camera still. its drives me crazy! also, you'd probably get better picture and quicker focus from an iPhone than all these fancy cameras everyone has. Sometimes simpler is better my friend.

[@magdumpmoravec3557]

Use a wall paper tool instead of those taping knives

[@robertmartinez6533]

👏👏👏👏👏👏

[@lliamcoxon9760]

Dot and dabbing plaster boards is easier

[@JB_58008]

Multimax was the best stuff for walls, then they made it "lite" and totally ruined it. All about shipping weights and $$$. Make sure you buy a new set of trowels with every bag of that junk

[@waldemarpalomo]

I just purchased books from cal osha safety order title 8 electrical safety orders and general industry safety orders

[@jakeklassen3702]

I kinda skipped through the video because I already know how to kerdi, just wanted to see how you do it, but why did you kerdi the floor? According to schluter all you have to do is band the seams and it’s waterproof. Unless of course your just over killing it like usual.

[@johnandrew9934]

I think Schluter wants you to cover the heat cable with kerdi in a shower

[@crazyeyes19523]

if ditra heat is in a shower you have to membrane the entire thing. water would pool in the pucks if you didn't

[@jakeklassen3702]

crazyeyes19523 well it shouldn’t puddle in the pucks because you skim the ditra before you would put down your floor tile. I just find some contradictions and inconsistencies in schluters standards. I use their products all the time but some stuff just don’t make sense.

[@patjosiah9356]

Does that seat say Milf🤣

[@patrickknapp5867]

I thought you talked all this trash about Kerdi, now your using it....

[@billydow1971]

Party shower

[@troyfrench9884]

Floating the walls seems like such a huge waste of time...

[@richhoffman5255]

Does not care about bond strength omg pretty important on the walls

[@GilBatesLovesyou]

It's only as strong as the application, is his point. If one has some theoretical bond strength in the spec sheet of 400PSI but sucks to handle, gets air pockets everywhere, shrinks, sags, etc, and one has a theoretical bond strength of 300PSI but doesn't do all those things, the 300PSI one will bond better.

[@Ebbrush3]

kids....buy a bucket knife

[@wyattburns6436]

Overkill with membrane .just lay tile over ditra heat ..waste of money and time for customer

[@joshschindel9103]

this camera work is sure making me sick. is there an earthquake???