If you need to decide which method is best for you I have a free shower waterproofing manual that you can download here. Shower waterproofing manual. Go get it – it’s free! And I’m not gonna use one of those damn annoying pop-ups! I hate those things…
There are several ways to prepare the wall of a shower for tile. Depending upon what was originally there, what stage the shower rebuild is currently in, and what type of tile you plan to install plays a minor part in choosing which method to use.
The most critical aspects of which product to choose are: how much work you’re willing to put in and how much money you’re willing to spend. The end result should be the same – a waterproof box. The methods used to accomplish that vary in effectiveness and cost. So we’ll start with what I consider the most bullet-proof method.
Kerdi Shower System
A company called Schluter makes a shower system called Kerdi. The entire system, which can include everything from the wall membrane down to the entire shower base, is considered by many professionals to currently be the top of the line in shower substrates and waterproofing membranes. And no, I don’t work for them. I don’t owe them money. And they don’t take me on those all expense paid vacations to Bermuda – bastards. I like their products anyway.
The waterproof membrane made by Schluter is called . . . well, Kerdi. It’s bright orange and you can see it from space. It is installed over regular drywall or cement backerboard with regular thinset. It makes your shower a big bright orange waterproof box that glows in the dark. Okay, it doesn’t glow in the dark.
The material is difficult to describe with words, it’s kind of like a fleece-lined rubber(ish) membrane. I like it for two reasons: It is the best available and it happens to be the easiest, least work intensive option (once you are used to working with it). While there is a fairly large learning curve to effectively work with it, Kerdi is fairly easy and very well documented. There is a wealth of infomation on the internet about it. Just Google Kerdi. Go ahead, I dare ya. Noble company also makes a similar membrane called NobleSeal, but it isn’t pretty bright orange.
Liquid Membranes
After Kerdi, a brush or roller applied liquid membrane such as RedGard works very well. It is applied with a brush or roller like a thick paint. It’s bright pink. You coat it once, after it changes to red, coat it again. Usually two coats is sufficient for any shower (except steam showers). After is sets overnight just go in and stick the tile to the membrane itself. It is a bit expensive, but they are also simple and quick to install.
There are several of these membranes on the market, the most common being Redgard. My favorite is Laticrete Hydroban. Laticrete also makes Hydrobarrier and Mapei has Aquadefense. They are all pretty much comparable.
Preparing shower walls with RedGard
If you are building a shower and want a manual describing the entire process you can find it here: Liquid waterproofing membranes for shower floors and walls
Cement or Fiber Based Backerboard
If you don’t want to spend the money for Kerdi or RedGard, this is your next best option. These are products such as Durock, Hardiebacker, and Fiberboard. While the product itself is not waterproof, it is water-resistant. The backerboard will actually hold water, as in water will soak through it. There needs to be a vapor barrier put up between the wall studs and the backerboard.
The unique thing about these products is that, although they are not waterproof, they will not become unstable with moisture. (That just means water doesn’t make it swell up.) To use these you must first install some type of moisture barrier over the wall framing. Get a 4 mil or thicker plastic (mil is just the thickness of the plastic) which can be purchased at places like Home Depot, and staple it to the studs of the wall framing. You can also adhere it to the studs using silicone. Completely cover all areas from the tub to the ceiling. The backerboard is then screwed onto the studs to make your shower walls. Then you just stick the tiles to the wall and shower away.
I also have a couple of manuals describing the entire process from the wall studs all the way up to a completely waterproofed shower substrate ready for tile. You can find them here:
Waterproof shower floor and walls manual
If you have a tub or pre-formed shower base and need to only do the walls you need this manual:
Waterproof tub and shower walls
Denshield
Denshield (and others like it) are similar to drywall in that they are lightweight and easy to install. It is a waterproof core laminated on each side with a fiberglass based face. It is installed like drywall except you need to run a bead of silicone between the sheets to waterproof the seams. You then need to use fiberglass mesh tape over the seams. It does not require a moisture or vapor barrier behind the sheets. When properly installed Denshield is an adequate tile substrate for shower walls and relatively affordable compared to alternative methods.
If you are building a shower and want to use a topically-faced wall substrate you can find that manual here: Building a shower with a traditional floor and topically-faced wall substrates
If you are just tiling around a tub or pre-formed shower pan you can find that manual here: Topically-faced wall substrates for tubs and shower walls
Plain Drywall *DO NOT DO THIS!!!
Yes, you can do it if you must. I absolutely do not recommend this! But I’m also realistic enough to know that if you decide this is what you’re going to do, I’m not gonna be able to stop you from here. You can not just go up to your drywall and start sticking tile to it – ever. There needs to be a moisture barrier between the drywall and the framing. At least then when water gets behind your tile and grout and disintegrates the drywall it won’t disintegrate your wall framing as well. Remember, if water gets to one of the studs not only will you be replacing the shower, you will need to do some serious repair work to your wall framing and possible structural work. Please also note that using this method runs the risk of parts of your wall literally falling apart if it gets wet – drywall disintegrates in water.
And it will. So don’t do this!
Unsuitable substrates for shower walls – no matter what you’ve been told
- GreenBoard, also known as green drywall. Never use this or you’ll get a lot of practice replacing showers.
- Backerboard without a moisture barrier.
- Drywall without a moisture barrier. (I do not recommend drywall as your substrate at all.)
- Any type of plain wood or plywood. Ever. No, painting it makes no difference.
I’m certain there are a lot of things I’m not thinking of that someone else will. If you wouldn’t let it set in a swimming pool for a week, don’t use it for your shower walls. That should clear it up.
The golden rule
Although there are many products that can be used for your shower wall, many should not be. Regardless of which method you choose one thing to keep in mind is that you need to have some type of waterproof membrane between your tile and your wall framing. Kerdi membranes and RedGard are both waterproof membranes that go directly on the wall. Plastic stapled to the frame before installing your substrate is also acceptable.
The main thing you need to ensure is that no water reach your wall studs – ever. Wood swells with moisture and the only place that excess swelling is going to go is right into the back of your tile. Remember, your tile is not waterproof so you want to adhere your tile to a substrate that is as waterproof as you can make it.
If you need to decide which method is best for you I have a free shower waterproofing manual that you can download here. Shower waterproofing manual. Go get it – it’s free!
Hi Roger. Is this where I leave a request for the shower waterproofing guide? Thank You SO much for your tireless care for us out here as we want to DO IT RIGHT ! You certainly demonstrate vast knowledge
through your experience!
Hi Stephen,
You can go to this page and fill out your name and email in the box on the right. The elves will send it right over to you. Shower Waterproofing Manual
Now am a bit worried after reading your site. I just finished putting tile up one wall around the tub/shower. Its an old house…with old iron tub..previous owners had just glued some kind of plastic lining to plywood. Finally, cleaned all up and placed backer board up and am where I am. How bad did I screw up without putting some kind of moisture barrier up between the backer board and plywood?
Thanks much. Have enjoyed the site.
Randy
Hi Randy,
Short term – no problem. Longer term (six months or so) water is going to eventually saturate that backerboard (completely normal) but rather than hitting a moisture barrier when it gets to the back it will hit wood – that’s when your problems will start. Once water hits that wood it will suck it in like a sponge and begin to swell. That swelling is going to cause excess movement in your substrate which will begin to crack the grout, and eventually tile. And your dog will burst into flames.
At this point you should remove the one wall of tile and either go over the backerboard with a topical membrane such as hydroban or redgard (or kerdi) or remove the backer, place a moisture barrier back there, and replace the backer. It’ll be a hell of a lot easier to fix just that now rather than that plus any damage it causes down the road.
Quick question (I hope) – we are installing a shower on a wall that connects to the garage. The wall has insulation with a kraft paper vapor barrier. If I hang a 4 mil plastic barrier on top of it under the backer board, will i be creating a double vapor barrier that can trap moisture and cause issues? I want it to be as waterproof as possible and long lasting. The county already signed off on the rough in framing and insulation as is and they will come back for the final once we hang the drywall and backer board.
thank you!!
Casey
Hi Casey,
Yes, it can create problems. All you need to do it just cut a slit down the middle of each piece of kraft paper to give any moisture that may be trapped in there a way to dissipate. It won’t harm anything concerning the insulation, you’ll still have the plastic barrier.
Great, thanks so much!!
Should i not use the Blue board and put the concrete board over the vapor barrier
Hey Rick,
Do not use the blue board – no reason for it at all. Just install the barrier to the studs and install the backerboard directly over that.
Should you always attach the the vapor barrier to the wall studs first? I was told to put the new blue or purple mold resistant sheetrock up first and then put the vapor barrier on.
How do I replace the green tile around a bathtub with a color that my wife wants. Do I need to just demolish and completely rebuild – or is there some way to “pry” the tile off (like some of the DIY sites show)? In other words – just how robust is the backer board typically? I’m trying to judge just how big a hole I am digging my self out of.
Thanks – very nice site from what I’ve read
Hey Dan,
Backerboard is very, very solid. That said, are you sure your current installation is over backerboard? Oftentimes tile like that is simply over drywall. You can try to just chip off the tile, sometimes it works and sometimes it doesn’t. The easiest way to remove it all is just remove the rows down the corners then the rows on the outside of the shower and remove the entire substrate, tile and all, at once.
Great site! Got a question. I replaced a window in my shower/bathtub tile area (yeah, lousy location for a window) Tile was broken out and I need to temporarily patch it for now pending a remodel in the future. This area is not in the direct path of the shower. It looks like I have two options: Use backer board and shim to the tile surface or hire a plasterer to float it. In either case, I would like to waterproof the stud framing. What would you recommend? I uploaded two pictures called FrontView and SideView for your review. Thanks.
Hey Dan,
Ideally you can put backerboard over it and use hydroban or redgard for the surface, silicone around the window. You can also use regular 4 mil plastic and silicone it to the window, install your backer, then install your tile.
Thanks Roger. One question: one of your tips mentioned using Liquid Nails as a shimming agent to level the backer board which as you saw from my photo is going to be not real pleasant to work with. Will the Liquid Nails approach still work with 4 mil plastic siliconed to the framing? It seems that the plastic might lend to some instability. If not, what do you think of using that deck membrane and nailing it to the studs? I just don’t want that wood to get wet until I move the tub and shower out of that area. Thanks for your help. BTW, I think the Elf theme of your site is pretty cool.
It will work. It will be a bit unstable until the liquid nails cures, but once it does it’ll be just fine. The deck membrane would work as well – probably better than the plastic.
Thanks!
Hi,
IM tiling my shower walls. I had the drywalls guys upgrade green board in the entire bath since it was small. Can I put a water proof membrane on top of the green board then tile over that or do I need to take Green board down and put up backer board then the membrane?
Thanks,
Brett
Hey Brett,
You can use kerdi – that’s the only one approved over a paper-faced gypsum board. Anything else you’ll need to use cement backerboard.
Hi,
Thanks for this very informative website. It helped raise my confidence to be able to fire my contractor who told me that the 40-yr-old green sheetrock around my tub is waterproof and if I agree to keep them there he will reimburse me $1200 for the wonder board that was supposed to replace it since he has already installed 80% of the tile before I pointed out to him what he has failed to do.
Christine
You’re very welcome – well done.
Roger,
Great site here, tons of good information!
We are preparing for a simultaneous Main Bath & Powder Room renovation in a 1920 home (we have a 3rd bathroom upstairs so we can be fully-functioning while the work is being done). The walls are wood lathe & plaster over stud framing. The original tub of course has a window on the long side wall, and has since been converted to a tub/shower. We love the natural light, so we are going with glass block infill to replace the wood window. Now for my 2 questions:
1) I am wondering if i can remove the existing tile, attempting to leave the lathe & plaster intact. Then go over the plaster with Kerdi or similar waterproofing membrane, and thinset tile over that?
2) How do the Kerdi and Tile terminate to the Glass Block on all 4 sides?
Thanks!
Hey Bob,
1. Yes, provided the plaster is in solid shape you can go right over it with kerdi. Any ‘similar’ membrane is not approved for gypsum-based backing, if you want to go over the plaster you should use kerdi. Not saying something else won’t work, just saying it might not. I wouldn’t chance it.
2. If installing a glass block window you should get the big plastic ‘U’ channels to inset them into. The tile can just be butted directly against them (leaving 1/16″ for expansion and siliconing it). You can see what that looks like before the tile is installed here: Glass block window in Fort Collins (You can click on it for a larger version) and the tile is just run right up to it. (That’s drywall because I used kerdi over it) The kerdi run right up to it as well and siliconed to the U-channel.
I would like to send you a picture (not of me but of my bathroom that’s being renovated by a contractor who is costing me all of my life’s savings and who now I think is ripping me off every way possible) and would like to get your input on what you think is wrong with it. I do not see a way here to attach a photo (or maybe I’m too tired to see it). Is this possible?
Hi Christine,
Yes, you can go here: http://floorelf.com/find-it and upload any photos you want. Please read through the page before you do.
Hello,
I just found this site and we are in the middle of replacing a fiberglass shower wall with tile wall. We are using Denshield as our backer – the problem lies in the fact that the tub is acrylic and the long wide against the wall is not wide enough to accommodate 1/2′ Denshield and the tile thickness – the tile wall will be thicker than the tub wall – we want to place the Denshield to the lip and then glue the remaining 1″ of tile to the acrylic tub edge. We are using 12×12 tiles so over 90% of the tile will be attached to the Denshield. Does this sound like a doable?
Thank you in advance
Hey Pam,
Completely, but you don’t need (nor want to) adhere the tile to the acrylic. It can just hang over that spot with nothing behind it, that won’t hurt anything. If you adhere it the acrylic will expand and contract at a different rate than the tile and that will lead to problems. Just make sure you silicone the bottom of the denshield to the top of the lip so there is no possible way that water can get behind the tub as it runs down the wall.
Roger,
We are in the process of adding a bathroom in our basement. We have the walls framed, insulation in between the studs and 4mil plastic sheathing stapled to the studs. Next, we have cement backerboard…my question is, can I apply a waterproof membrane over the top of the cement board before applying our tile? I am a little confused about the double vapor barrier and the mold sandwich since cement board doesn’t mold I am not sure what would mold. Any help you can give me is appreciated! One other issue that concerns me is when my husband and father-in-law installed the shower pan liner, my father-in-law thought it would be alright to cut the liner at the curb to fold it over the top then he used silicone to adhere cement board over the liner and 3 2×4’s…I told them NOT to cut the liner and that it was not supposed to be cut but they didn’t listen to me, so now my concern is that water will get into the curb and even though the wood is treated it is not waterproof! I spent a ton of money on quartzite tile and glass mosaic and I do not want to have to rip out the curb in a year or two, can I use the roll-on waterproof membrane here to?
Sorry if I am confusing…just frustrated! I have called a contractor but he hasn’t gotten back to me yet and I really want to start tiling this weekend!
Thank You again,
Trisha
Hi Trisha,
Anything trapped (moisture included) between the two barriers, including anything at all that may be on the board, can feed mold. Food for mold is present everywhere, even in the air. The key to eliminating mold is to properly contain and drain water so it is not trapped and/or stagnant. If you do that, mold won’t grow. If you have the moisture barrier do not use a topical membrane as well.
The curb is a problem. First of all, if your shower is on a concrete substrate you can not use wood on it for your curb, it will absorb moisture from the concrete. If you’ve used pressure treated wood (you mentioned it was treated) that NEEDS to be removed. The moisture from the concrete will not affect it, but it will dry out over time. When treated lumber dries out it warps and twists. When that happens it does the same to anything installed over it. Check out my ‘flawed’ page for photos of that exact problem. You need to use bricks for the curb. The liner does need to be cut over the curb, but there needs to be ‘dam corners’ installed where it was cut to fix the waterproofing. It can not be cut and just left.
Your curb needs to be fixed, it is the first place that will have problems in an incorrectly built shower. I know you want to start tiling this weekend, but you need to fix that curb first. Redgard will not fix the problem.
Roger,
Thank You for the quick response! I will pull out the curb in the morning and head back to the tile shop to buy the dam corners for the cut liner. I just hope that I am able to get the cement board off of the liner without damaging it. I did purchase a “quick curb” system that they didn’t think we needed to use since they used the 2×4’s but I think I will use that and the floor mix that we used for the shower pan to build a curb…I hope it works!
The quick-curb will work fine and provided he just used silicone to adhere the liner it will come right off, that won’t stick very well at all. You should be able to get that fixed just fine.
This is the clown from Colorado that people get there edvice from…Good luck. He is a fake. There is no code in the state of Colorado. So what he tells you is not by code. I am from California were we pro’s have to do things by code. All he has is a business tax license and any fool can get one in the midwest. He is no contractor. Just an elf with a web-site See you around bad person elf.
I am from California were we have code’s to hold up to. This elf is a clown and if anyone go’s to you to get info, they are to. Did I hit a soft stop in your black sole. The world is a small place and you give up to much info. Time thats all it takes you fool.
A little note for my readers: This is what I emailed this ‘pro’. While I’ve left two of his 21 comments he decided to leave on my site this afternoon I have deleted the other 19. They all included the ignorant rants above as well as personal insults directed towards readers of my site. I will include my reader’s replies to him after this post, but they will likely make little sense since I’ve gotten rid of much of this clown’s stupidity. Maybe he’ll stop back by and reply, eh?
Well hi there fucktard,
Let me ask you something: if you are such a ’tile pro’ why are you sitting around on a Thursday afternoon attacking people you know nothing about with idiotic, misspelled, incoherent, adolescent grammar laden rants? Let me let you in on a little secret – no one gives a fuck what you think. Only immature insecure people who lack the ability to deal with their own problems feel the need to attack others. Much easier when you don’t know those people, isn’t it?
The only thing you are correct about is that there is no licensing requirement in the STATE of Colorado – there are licensing requirements for individual counties. So while you are able to sit down and take a three hour test and work all over the state of California (or is it South Dakota, JD? See, I’m a bit confused here since you posted under two different usernames and linked your website to the first before MY READERS began telling you what a complete fucking moron you are – so which is it?) I must take a test for each individual county in which I work. So you’re correct about that part, but, as apparently is your forte, incorrect (and incoherent) about everything else.
You are just now receiving a reply to your idiocy because, unlike your misleading fake alias, I actually am a real tile pro and am not sitting on my ass in front of a computer at 2:00 in the afternoon on a Thursday. So what gives? Word finally get around that you are an incompetent ass? Or are you like every other ‘collect the check and skip town’ asshole out to destroy people’s homes and just wasting time while waiting for the moving truck?
No matter. I’ll just make this short and sweet for you: you have no idea with whom you are beginning a pissing contest. There is a reason I know you posted with two different monikers and that you are, in fact, the same worthless piece of shit. There is also a reason I know you claim to be from CA and are, in fact, likely in SD. If you whip out your balls prepare to have them smacked with a sledgehammer. Attack my website again with your drunken, incoherent idiocy and you will have bigger problems than no work on a Thursday.
OH! And have a nice day.
I would like to apologize to my readers for the troll, when you get popular they’re always around. Sounds like this guy’s just pissed that homeowners are not hiring HIM. Not really our problem though.
JD Tile, (Edit by Roger – That’s the other name he posted with)
ARE YOU KIDDING ME??
First of all, you have a bad attitude. Second of all, if you do good work you wouldn’t be worrying about getting work, there is plenty to go around. Word of mouth, referrals are your best friend.
Next, a lot of people are on a budget and can’t afford to hire you, but still need to remodel.
Also, I would rather do-it-myself because there are so many so called “professionals” out there who do crappy work, just want to get in and get out, cut corners, giving homeowners more of a headache than help. They hired someone like you who wasn’t nice to people, took there money, did crap work, and now they have no choice but to go to this AWESOME website that Roger has given all of his time to, (for NOTHING in return), because they ran out of money paying the “professional”, they have a huge mess, and you won’t come back and fix your crappy work.
PLEASE REPLY,
MIKE S
PS I’m nominating you Roger and ‘Floor Elf’ for web site of the year.
@ JD: Are you a troll?? You sound (and spell) like it.
For every DIY who posts a question, there are probably a dozen readers who are simply here to learn something, including how a good job should be done and what to expect from a competent tile pro. Perhaps that is part of your problem.
I’m the Pat that wrote the questions on Jan 9. I did not write the response today but I don’t disagree with that Pat. I happen to be female and have remodeled over 25 houses. I don’t profess to be a tile pro any more than you can profess to be a gentleman. I love this website and have been reading many of the posts to learn and get better at making my home more beautiful. Martha Stewart’s bank account is probably larger than all of our bank accounts combined and certainly larger than the 2 small tiles you must have in your pants.
@ Original Pat: My apologies for the confusion. I am a “lurker” who reads this site regularly to learn enough to deal intelligently with tradesmen and craftsmen, whom I happen to enjoy and respect for their expertise.
@ “Tile guy” — you have revealed enough of yourself by now so that no additional comment is necessary. Please do not continue to degrade an excellent website that does not belong to you.
Wow, 2 nasty posts for no reason!
Actually, I think I am a reasonable person. I took a chance and posted a rather long and drawn out question. I got a very simple, logical solution in return.
I guess I am just a happy fool!
Hey, Mr. Real Tile Pro, Dude!! I only have one question and then you can direct your hatred towards me. Why are you so angry?
Roger,
I have a question, why was this “tile pro” posting his stupidity at 10:00 AM on a Thursday? I notice you always answer your posts in the evening after working a full day. This Knucklehead must not have worked today, I wonder why!!!!
Mike
Oops,
I was writing my reply while you were posting your response. You got that he mustn’t have been very productive today.
Yeah, he’s a piece of work, eh?
Probably just mad that no one is hiring him.
I bought a Kohler pre-formed shower pan 48″ square. I want to build a bench at the right end to make the shower rectangular 48 x 60. The back side of the 60″ will be wall with glass tile, the left side of the 48″ will be solid surface (corian) and the right side of the 48 will be where the bench is located and covered with solid surface (corian). The remaining front and upper bench side will be enclosed glass. I plan to cover all the stud wall surfaces with a membrane and Hardibacker as well as the bench with Hardibacker. Can I cover all the seams with Kerdi seam paper even if I don’t use the membrane all over the walls? It seems that the Kerdi seam sealer would be better than the fiberglass mesh tape. I’m spending alot of money on this project and don’t want it to leak, what do you think? Also the Kohler shower pan doesn’t have a ledge to screw into the wall, only a 2″ high 1/4″ wide wall above the base. Should the solid surface and tile stop at the top of the shower pan or overlap the shower pan lip? Thanks so much for your help. Any and all comments are welcome.
Hey Pat,
You can use the kerdi-band, but it isn’t necassary. The membrane that you use over the studs is your waterproofing, nothing else is needed. The fiberglass mesh and thinset has nothing to do with waterproofing, it is to lock the separate sheets of backerboard together to create a monolithic wall which moves all at once, rather than each sheet moving individually.
Your waterproofing membrane over the studs needs to run down over that base lip and be siliconed to it. The backer and tile is then run down over the front of that lip to within 1/8″ of the horizontal surface of the base arm.
Hello again Roger,
Happy New Year!
I am trying to figure out how to overlap the plastic 4mil vapor barrier. ( I am actually thinking of ripping out the plastic and just using Redguard everywhere). Anyways, I have a free standing shower with a tileredi base. The left side of the shower is the outside wall, the right side is a half wall with the air tub on the other side. (I have put the plastic on the left and back shower walls and got stuck by the half wall.) That half wall between the shower and tub will have glass on it for the enclosure. The entire back wall (shower left, tub right) as well as most of the other walls in the bathroom will be tiled floor to ceiling with the 4″ clay tiles I mentioned in a previous post. I also built a step up into the tub. Now for all the questions.
1. To cover the wood of the half wall with plastic I will have to cut, overlap and/or fold over the plastic from the back wall, which could one way or another be creating a double plastic barrier thereby trapping moisture and causing mold. I’m having the same issue regarding the step to the tub which is curved.
2. Do I have to waterproof areas such as the middle of the room, or 3 feet above the tub enclosure, or even the step, where the tiles won’t be soaking in water like in the shower? If you help me to decide to go with the Redguard and rip out the plastic, do I Redgaurd floor to ceiling everywhere? One three gallon pail is manageable, 3-4 might make my checking account burst into flames.
3. Unrelated grout question. You recommended epoxy grout for the clay tiles. Laticrete directions say ‘Allow grout to cure for 10 days at 70°F (21°C) prior to use in submerged applications or steam rooms.’ Does that mean not to use the shower for 10 days or are they talking about a pool application etc.?
I really appreciate your time.
Thank you,
Mike S
Hey Mike,
1. You only need the plastic on the shower side and on top of the 1/2 wall. It only needs to be behind all the backerboard inside the shower. Anything on the tub side will evaporate long before it saturates the backer.
2. No, you do not need to waterproof those areas. The only thing that needs to be waterproofed are any areas inside the shower below the shower head. Anything else is just extra and, although a good idea, is not technically necessary.
3. They are talking about pools, steam showers, etc. For normal showers I normally wait 48 hours, although 24 is all that is required.
Hi Roger,
The answer is probably obvious in your article, but I want to be sure… We are in the middle of a DIY bathroom redo. We have a standard three wall tub/shower enclosure. The last owner installed a fiberglass shower wall which literally fell off of the wall into the shower. We are planning to tile, but the surround walls are drywall. There is no moisture damage to the walls and there was no damage from the failed fiberglass walls. I doubt they are greenboard and I would be shocked if there is a vapor barrier behind the drywall. We really don’t want to take the walls down, is it sufficient to use the Kerdi or RedGard directly on the plain drywall and what are the risks of this method? If we choose to take the wall down, would you recommend backer board and Kerdi?
THANKS!
Hi Dana,
You can use kerdi – that will be just fine, drywall is one of their recommended substrates. You can not use redgard, it is not approved for use over drywall in a wet area. Using kerdi would be completely normal, though.
Hi, I’m wondering if you can help, I’m replacing the tiles with my shower area as water has got through to the plasterboard and ruinined it, everywhere I look people recommend cement boards for shower areas I’m trying to repair an enclosed by 3 walls shower area and I’m not sure if the walls are studded or double skinned plasterboard, can any one advise the best point of call would be. And can I use cement boards on plaster
Kind regards
Daz
Hi Daz,
You can use backers on plaster but you’ll need to figure out a way to anchor them if you don’t have studs behind there. It would be easier to give you a more specific answer once you get some torn out and know exactly what’s back there.
Happy new year roger! Hope I catch you before the liqor starts flowing. I am confused. I was reading your article about putting down the dry packed mortar shower floor, and using brick for a curb, what about the wood framing in the wall? It is below the vapor barrier behind the cement board, and the wet mortar will be touching it. Does it need to have plastic or a seal of some sort before I put down the mortar? In the same vein, I am putting a short wall Between the shower and the toilet, the top will be glassed, but floor to butt height while seated on the throne, will be tiled. So I was going to use pressured treated 2×4 on my cement slab, and build the wall cover with vapor barrier on the shower side, and tile, but now I am sobering should I have brick on the slab, then the 2×4 and go up from there? Health, wealth , and happiness in 2012
Hi Sally,
You want bricks on your curb because wood will actually pull moisture from the concrete itself. Unlike the walls, the only thing over your curb substrate will be tile. Once it sucks moisture from the concrete it will swell and place pressure up into the back of your tile. Footers in the wall normally consist of pressure treated wood, and that’s fine for a wall. When a wall footer absorbs moisture from the concrete and swells or contracts – that movement is pressed up against an empty wall cavity – vertically – and into the studs – vertically. Not a problem when you don’t have tile on top of that vertical column.
As far as the half wall you still have the vertical pressure but it is distributed over two or three feet – not three inches like a curb would be. By the time it reaches the top of that half wall it is essentially nullified and not enough to affect tile or anything else installed on top of it.
Keep in mind that all this expansion and contraction, which is completely normal in structures, is always directly proportional to the amount of space it has to expand and contract. A normal wall has eight feet to do this, a half wall 2-3 feet, a curb only has 3-6 inches. Big difference. If you use bricks for your curb it isn’t an issue.
Since you are now sobering – go have a drink!
I have a big question. Can I apply waterproofing membrane over any dry surface, like old tile and spots where fixtures and tile meet? The reason being is that we bought a house at the end of hte high market (had no choice had to sell and move) and the house is a ranch that is very solid and probably would be tight as a drum and fine if the elderly owner wasn’t advised by someone to ‘update’ the 1.5 baths. She hired someone who used contractors special lowes bargain basement ceramic tile, particle board covered with plastic sheathing and rinky dink fixtures that are prone to collecting gunk. The worst and main problem is though, that the contractor didn’t waterproof a single thing. Just framed the tub and shower and tiled over what I hope at least is cement board. I’m not even sure about that. So within a month of living here, we started noticing water pouring into the basement from under tub and shower. Now it’s five years later, i’ve recaulked, regrouted and it’s really pointless. The shower turns to black, gray and orange mold and mildew within 6 weeks and the tub is now strapped with silver duct tape to try and staunch the gaps where the fixtures meet the tub tile and the tub meets the wall tile….it looks horrible in both rooms and i really no longer have the time or patience to strip every bit of caulk on my own, dry prime and recaulk it only to be showering in a disease shower. The tub is a lost cause too> The only solution is to gut them and redo the. We aren’t plumbers , dont have help, babysitters or money or time so even a DIY project would really be impossible. So i had the thought of shutting down the shower which is a huge inconvenience. We did without it for 5 months once because i couldn’t find the time to recaulk and regrout. So my thought was shut down the shower and clean the tub area, remove the duct tape and paint waterproofing membrane everywhere the tape was (i also have tile falling off the wall where the floor and tub meet now too). Would this be more efficient than more duct tape until the miracle day when we can remodel the baths?
Hi Viki,
You can apply it but it won’t last. Redgard, or any liquid waterproofing, is not meant to be a wear surface. That simply means that it will not be durable enough to withstand direct contact of elements such as water and shampoo in your shower. It is meant to have a tile covering over it to limit this exposure. It will eventually wear away. Maybe a week, maybe a month, but that is an expensive short-term fix.
Given your lack of time and funds in the immediate future your best bet, although not ideal nor permanent, would be to go to Home Depot and get some fiberglass (acrylic) panels for showers and silicone them up there over the tile. It will last a year or two and should at least stop the leak and limit structural damage. You can likely do that for the same price as the waterproofing that won’t last.
In the process of adding a new shower to my garage. They’ve just hotmopped the pan and now I find your site and discover the Kerdi system. Is it possible to use this over the hotmop? I’m envisioning a mortar bed over hotmop and then the Kerdi membrane. I really want this installation to last and I’m discovering some bad press on hotmop pans, in contradiction to what my plumber told me. I’ll be laying the tile myself. Thanks, Cindy
Hi Cindy,
You really shouldn’t do that. It will create a mud deck between two impervious membranes which can lead to problems. If you are set on using the kerdi for your pan the hot-mop should be removed. You can use kerdi on the walls over a hot-mopped pan if you want.
Hi Roger,
The obvious answer to my question is probably yes, but I’ll go ahead and ask anyway! If I put a Kerdi membrane on top of the backer board does it mean that I don’t have to put sheeting between the studs and backer board?
Hi Jennifer,
Yes.
Shortest. Answer. Ever.
Thanks.
Good Morning Roger,
I have finished tiling and ready for the frameless shower door measurement and somewhere in the process I have goofed big time about the leveling of the marble shower pan/liner. The curb slopes outward ever so slightly. It is one whole piece with the curb built in.. the guy recommended a piece of granite cut to go straight across to have it slope inward. Do you think that is the best option or can the marble be resanded to give it the proper grade?
Another problem I had when tiling around the opening for the shower lever is that the black plastic of the control nozzle had to be removed and it left a bigger opening, is there anything that can be done? Leaving it on made the covering stick out about 3/4 inch, so we removed it. I was told it is ok., but it still leaves a eerie feeling I had left too much space. The cover will hide it all, but seems too open.
I sure wish I would have seen your site before I even started this project, but it is nearing end. Or at least I hope so!
Thanks again and Happy Holidays
Hi Janice,
Any natural stone, provided it is thick enough, can be sanded down to the proper pitch and repolished. The cover (escutcheon) should have a foam ring around the backside of it which will seal the valve – no problems at all.
Hi Roger,
Perfect Timing in seeing your posting.
I’m in the process of having a steam shower installed. Work already accomplished. Moved shower location, new stud walls and pony wall added. The floor drain moved and a new instaset drain with ebbe square drain adapter and drain cover is being used. I’m hoping to pull off a ‘beach’ entry to the shower space but may need to have a low curb. Shower floor/pan will be hot-mopped and that includes an area that extends up the walls by about a foot. (I live in California where hot-mopping is common).
So to the question. Any advice on how to best prepare the shower walls and ceiling for a steam room application? The new wall tiles will be a natural stone.
The tile installers that have provided estimates so far seem to be going with a method that uses tar paper backing and floated walls over diamond lathe and then apply the tile. They don’t seem to be concerned when I ask about the steam shower element. Only one installer said that I should have an inline fan installed in the shower ceiling to remove steam after the steam bath but that was the only difference.
Is this an acceptable way to build a steam shower? Is there something additional or different they should do instead?
thanks!
Debbie
Hi Debbie,
Yes, there is a lot that needs to be taken into consideration including, but not limited to, movement (a lot of it), vapor control (fan) and proper vapor permeability of the waterproof membrane. Laticrete has made a very in-depth steam room manual which you can download and read here: Laticrete steam room manual
Hi Roger,
Thanks for the reply and advice and given your site and others I’ve read recently I’ll be ditching the hot-mopping and current drain and going the Kerdi route. Thanks for a great site and helpful insight.
All the best to you in the New Year!!!
Cheers!
Hi Roger –
First, Merry Christmas and Happy Holidays. I hope you and your family have a safe and enjoyable holiday weekend.
Question for you. Just installed my mud deck and am trying to think ahead. My shower is going to be a hybrid of topical / traditional system. I am using a membrane on the floor and hardie board on the walls w/water proofing (redgard). I have read your guide so I am appropriately armed. Anyhow, my question is with regards to where traditional meets topical.
With my walls waterproofed and my floor being a membrane, is there anything i need to do specifically where one meets the other. I was planning to use Redgard on the walls and where the wall meets the floor I was planning to use tape / morter on the joint and then Redgard thru the joint extending perhaps a few inches onto the floor.
Is this correct or is there a different / better way that I should address the joints where the wall meets the floor?
Thanks again for all of the great information.
Regards,
Dale
Hey Dale,
Actually you should leave the backer about 1/16″ – 1/8″ off the mud deck and silicone between the two. Backerboards can wick moisture, if the backer is touching the mud, and the mud is wet (which it will be), the backer can actually wick moisture behind your waterproofing (redgard) on the walls. So silicone between the two and just paint the redgard over the bead of silicone and about two inches out onto the floor. That’s the only thing that’s different, other than that you’re good to go.
Have a great Christmas!
Awesome. Thank you so much for the information….Again!
Regards,
Dale