Waterproofing
Just look at you! Sitting there with a hole in the wall of your shower. What are we gonna do with you? If you do not happen to be sitting there with a hole in the shower of your wall read How to Build a Niche for your Shower – Part 1 and join all the cool kids. We’ll wait…
There, now you’re one of the cool kids. Now take your beer Pepsi off that niche shelf so we can waterproof it. You have a couple of different methods with which you can accomplish this.
Liquid Waterproofing Membranes
These products are usually readily available and fairly simple to use. Products such as Custom’s Redgard and Laticrete’s 9235, Hydroban, Hydrobarrier, etc. are all a thick, paint-like product which is brushed or rolled on to your substrate to waterproof it. You should only use these products if you are using a cementious backerboard as your shower substrate, they should not be used over regular drywall.
If you do have a cementious backerboard and choose to use one of these products for waterproofing simply follow the directions with whichever product you choose. Make absolutely certain that you get enough of the product in your niche to effectively waterproof it. The specifications vary but the best way I can explain it with a general rule would be the thickness of a credit card. Two or three good coats and you should have a layer on your substrate equivalent to the thickness of a credit card – that would be the correct amount.
I use to waterproof niches this way until I started doing them with Kerdi. Unfortunately I don’t have any photos of a niche I’ve waterproofed with a liquid membrane. Just make certain you have every (literally) pinhole and corner covered very well. For the remainder of this post I will describe waterproofing your niche with…
Schluter Kerdi
Kerdi is now my preferred method of waterproofing a niche, bench, floor, wall, beer Pepsi cooler, just about everything. For those unfamiliar with Kerdi it is the orange membrane on the shower walls in all my photos. It is a thin polyethylene sheet which is installed directly to drywall and/or deck mud as well as other substrates, to make it waterproof. It is easily cut with scissors or a razor blade and can be folded, molded around curves, etc. and is installed directly to your substrate with regular (unmodified) thinset. A very versatile product.
While there are countless ways to utilize Kerdi to make your niche waterproof I am going to walk you through the way to cut and install it using one single sheet cut to size for your niche. I say type there are countless ways because there is really no *particular* way which Kerdi must be installed. As long as every piece is overlapped 2″ your substrate will be waterproof – no matter how many pieces you use. I just prefer a single piece cut to whatever size I need for the particular niche.
So what size do you need for your niche? Here’s how to figure it out. The badly created diagram to the right explains it better than I can with words, you can click on it for a full-size version.
It is basically the width of your niche plus the depth (twice) plus 2″ (twice). See? I told you the diagram was easier.
For my 13 x 13 x 3 niche the measurement for the piece of Kerdi is 23 x 23. That is 13 + 3 + 3 + 2 + 2 = 23. Width + depth + depth + 2 + 2 = width of kerdi. The two inches (twice) is for the overlap on the outside of the niche. Remember I said kerdi needs to be overlapped 2″ – that’s what that is. 2″ on each side of the niche.
For a square niche both measurements will be the same. If you are creating a rectangular niche the width and height measurements will be different – they need to be figured differently.
Photo 1
So here is my piece of kerdi for the niche. (Photo 1) You can see the measurements marked out. Take a ball-point pen or pencil and mark the measurement lines on the piece of kerdi.
At the bottom right of this piece I have marked the two partial cuts you need to make in every corner as well as the small square piece to remove. (Hold on to that piece – don’t throw it away)
Cutting each corner in this manner will allow you to fold the kerdi into your niche correctly and have an exact fit. Make sure you do not cut the lines too far, it’s always better to cut them a bit short and fine-tune it later.
Photo 2 - Kerdi cut for niche
In photo 2 the kerdi is cut to fit into the niche. After you get it all cut you should place it into your niche to ensure that it fits correctly. Just take the piece of kerdi and place it into your niche like photo 3 here:
Photo 3 - Dry-fitting the kerdi
Take the inside corners – the ones that go into the back corners of your niche, and push them tightly into each corner. If measured correctly the corner marks on the inside square should fit perfectly. Wrap the top and bottom flaps over the niche and onto the wall outside.
The side flaps then get smoothed onto the sides and all the strange corner pieces you cut out will fold over the top and bottom flaps and outside to the wall with a 2″ overlap. If fitted properly it should look like photo 4 here:
Photo 4 - Correctly cut and fitted
At this point make any minor adjustments in the cuts or remove any excess you may have and make all the folds over all the corners to make sure they fit tightly.
After you ensure that the fit is correct its time to actually install it. Make sure you are comfortable with the way it fits and how it folds into there. Remove it and replace it a couple of times until you are sure you know how to do it. Once you start playing with the thinset it gets really messy very quickly if you need to make adjustments. I became a tile guy because I like playing in the mud – you may not.
Pull the piece out of there and comb your thinset into every corner and part of the niche and about 2 1/2″ around the outside of the opening. You need to make sure you get every little bit covered. There must be full coverage behind the kerdi to make everything waterproof.
Photo 5 - Combing thinset into and around niche for kerdi
Photo 6 - Placing the kerdi into the niche
When you go to place the kerdi into the niche you should fold in the sides as it will be placed into the wall. By folding the flaps over and in before placing the kerdi in it will help get it in the right place with a minimum of mess.
Start with the upper two corners in the back of the niche and press them in there very firmly. Make sure the line between those two corners follows the corner of the wall in the upper back of the niche. This is why you want to draw all the lines onto the kerdi – it will assist in getting the piece all lines up and in the space straight and square.
When you get those corners and the line between them pressed in firmly run your fingers down each side of the back of the niche to make sure the lines follow the niche. The lines you drew on your kerdi should follow the lines of the niche exactly.
Smooth out the entire interior of your niche starting with the center of the back wall and working outward. You need to make certain there are no air pockets behind your kerdi. Once the back wall is firmly in place start with the sides of the niche working from the back to the front wall again ensuring no air pockets remain.
Once the entire inside of the niche is smoothed down and flat start with the main flaps by using your index finger and thumb along the outside edge of the niche to get a nice, square transition around the corner like this:
Photo 7 - Smoothing outside edges of niche
If you look closely (or click on it for a full-size view) you will notice that only the first inch or so around the outside edges are completely smoothed down. You want to get that nice and tight before worrying about the remainder of those flaps.
After you get the large, main flaps installed and smoothed out flat you can start with the inside corner flaps. Just do one or two at a time and don’t rush through these – they are the point where your overlaps create the waterproof aspects. I do the two opposite corners at a time.
Photo 8 - Installing two of the corner flaps
Photo 9 - Finish installing the remaining flaps
You want to take considerable time and great attention to detail while installing these flaps. The tighter the seams are together where they overlap the more dependable they will be. Kerdi is made waterproof by the overlapping and attaching of the seams – the tighter the better. Get it all smoothed out and tucked in and you will have an absolutely waterproofed hole in your shower wall. That is, after all, what you are building – a hole in the wall.
Now, if you are anal retentive attentive to detail like I am there will probably be one or two spots which may concern you for one reason or another. Remember those 2″ square pieces you cut out of the corners that I told you not to throw away? There’s your patch. Just comb thinset over the spot that’ll keep you awake tonight and install the patch over it. The outside corners of your niche may be one of those areas.
See photo 9? It’s a frickin’ mess. If you aren’t making a bit of a mess you aren’t doing it correctly. Yours should be a bigger mess than mine. Don’t be afraid of it – thinset is your friend. Besides it looks better after is sets – see:
Finished
If you do it the right way you will never have to worry about leaks, standing water or any other fun problems associated with an improperly built hole in the wall. When done correctly you will end up with an absolutely waterproof niche in which to store your rubber ducky! See:
Thought I was joking, huh?
You thought I was joking about the rubber ducky, didn’t you? I wasn’t. I build showers – I like rubber duckies.
In my next post I will describe various ways you can place tile in your waterproofed niche for maximum rubber ducky storage.
Heya Roger,
Just curious, assuming i am using the vapor barrier method, how exactly do i waterproof my niche? i have a tub of redguard that i bought for a few reasons (basically because im super paranoid) and i was wondering if i can use that to waterproof the niche.
Hey Bill,
When you cut the hole out of the vapor barrier for the niche silicone the perimeter of that cutout to the back of the backerboard and use the redgard to waterproof the inside of the niche. The silicone will create a dam around it so no water gets behind the niche itself and the redgard will prevent water from getting into the front.
Roger,
Thanks for the tip, it should work marvelously. That being said, i still haven’d decided if i love you, or hate you. When i first found your page (3 days into building my shower) i was overwhelmed by the wealth and quality of information you have put together. But as i read on, the realization of how many things i had done or was doing wrong finally sunk in (bad advice from the local “experts”…it was a lot) So after ripping everything out and turning to alcohol to ease the pain, i finally got everything g So i guess, what i’m really trying to say, is thanks . . . for making my life hell, but my shower amazing! I think i owe you a drink after this is all over with. (if i’m still alive)oing perfect. My pre-slope now drains well, my curb is brick and not PT lumber, and i have something a lot better than the .4mil drop cloth i was recommended as a vapor barrier. It might take a week and a few more bruised appendages than i was hoping for, but Murphy willing, my mother is gonna have one hell of a shower.
Oh wow, my comment got ripped in half. let me fix it rq. (sorry for spam)
Roger,
Thanks for the tip, it should work marvelously. That being said, i still haven’d decided if i love you, or hate you. When i first found your page (3 days into building my shower) i was overwhelmed by the wealth and quality of information you have put together. But as i read on, the realization of how many things i had done or was doing wrong finally sunk in (bad advice from the local “experts”…it was a lot) So after ripping everything out and turning to alcohol to ease the pain, i finally got everything going perfect. My pre-slope now drains well, my curb is brick and not PT lumber, and i have something a lot better than the .4mil drop cloth i was recommended as a vapor barrier. It might take a week and a few more bruised appendages than i was hoping for, but Murphy willing, my mother is gonna have one hell of a shower.
So i guess, what i’m really trying to say, is thanks . . . for making my life hell, but my shower amazing! I think i owe you a drink after this is all over with. (if i’m still alive)
Hi Roger:
I have stumbled across your website (thankfully) and would like to ask you a question about my ‘niche’. It is about 12 x 24 x 5 inches. I plan on using granite tiles starting with the back with a piece 12 x 24 x 3/8. I will then thinset the bottom, top and sides. Finally, I was planning on using silicone on the edges (and to install a shelf). My question: do I really need to use Kerdi in this application? (the shower walls are covered with densshield and the niche is constructed with plywood)
Thanks
Larry Laughlin
Hey Larry,
You don’t need kerdi – but you do need some sort of waterproofing. If you have denshield lining the niche and properly siliconed at the seams and fastener penetrations then it’s fine – tile right over it. If you are planning on tiling directly to plywood then you’ll end up with a huge moldy mess in there in short order.
You can use the denshield, kerdi, redgard or any other approved topical membrane – but you do need waterproofing in there. Granite, while not as porous as marble or travertine, still absorbs water. Once that gets to the plywood it’s gonna be just like a big sponge in your wall cavity.
Should I use plastic corner bead beneath the kerdi band on outside corners when kerdi banding over denshield? Hopefully that’ll be the last question.
Hey Garth,
If you want to. It won’t hurt anything. If you are wrapping tile around the corner there’s really no need for it, though. The tile will protect the corner.
if I do use the kerdi band on external seams, should I use the alkaline resistant tape and mortar first and then put the kerdi bamd over it, or does the kerdi act as a waterproofer and reinforcement for the outside edge? Thank you tile master. Not sure how to add to my old past so i’m just putting a new one
Hey Garth,
No need to tape and mud when using kerdi-band. The kerdi does the same thing and waterproofs it all at the same time.
I apologize if this is answered in the plethora of information you have on your website but I can’t seem to find it. When using denshield for a waterproof barrier i understand the silicon at the joints and screws. However, I’m not sure how to waterproof an outside corner because the core material will be exposed. Thanks for the amazing website!
Hi Garth,
If you look at a sheet of denshield the waterproofing wraps around both sides of the board. You need to make your cuts so that one of the wrapped edges covers the exposed edge, then silicone between them. Alternatively you can use kerdi-band or redgard to waterproof an exposed edge – probably not something you have on-hand, though.
Roger,
I’m curious why you place the piece of Kerdi that you cut out for your niche at the back of your niche. You then show us in part 2 how to use a single piece of Kerdi to waterproof your niche. Why the extra layer in the back?
Hey Dan,
Because most bullnosed tile is three inches wide – most wall cavities are 3 1/2″ wide. Placing an additional 1/2″ into the back of the niche allows you to have a single piece of bullnose as the niche perimeter without having a 1/2″ sliver of tile behind it – that looks like crap.
It has nothing at all to do with waterproofing – it’s simply a perfectly sized shim for the back of the niche.
Roger,
Thanks for all the great info. I’m looking for Part 3 and Part 4 of your series — have they been posted yet? Also, will you be covering how to seal around piping penetrations?
Hey David,
*I fixed it – they are now right under the post. Thanks.
If you scroll all the way down past all the comments, to the bottom of the page, all posts have links to both the next post and the last. Part 3 is here: Building a shower niche part 3
Sorry, I’m not explaining it right and to be honest I’m not use I understand. I wasn’t planning on doing the bottom row first just using it as a guide in which to draw a level line on the wall. However, its trying to use the lever that is throwing off this line. Most of the infor I read is for 4×4 tile not 12×12 so this is throwing for a loop.
If you have a level tub there’s absolutely no reason not to start with the bottom row. The only reason to start with the second row is either your base (tub) is not level, thus the need to begin with a level row one tile up, or you are installing tile beneath the first row like on a shower floor and are doing the wall first. If your tub is level stack the tile up the wall beginning at the tub.
I’m using the Kerdi band from HD couldn’t find the sheet. Now I need to put the mesh tape over the corner before I put the thinset for the Kerdi band? Also, is a putty knife okay to spread the thinset in the niche?
Hey Mori,
No need for the tape under the kerdi-band, it does the same thing. A putty knife will be fine for the niche.
Thanks. One more question. I’m trying to get a row of tile up tonight. I was told since my tub is leveled I could use my tile which is 12×12 plus 1/8. Draw a line and use my leveler to draw the line on the wall. However, when I try this I’m a few mm above the tile line that I drew which makes my tile a few mm above the original 1/8 starting point. And how am I suppose to add a batten to this?
Move your line. I don’t really understand what you’re asking me. If you are placing the bottom row up just install it and lay your level on the row of tiles and shim them up to be flat and level against it. The exact measurement isn’t as important as the level line. Doesn’t matter where the line is vertically in relation to the tub, as long as you have a level base.
Maybe I’m completely misunderstanding what you’re asking.
Thanks, I know I’m asking a lot of questions. Two of the three sides of the tub are leveled.
I use the kerdi band in my niche, actually I ended up using 95% of it. I’m sure there is a less wasteful way but I had a hell of a time covering the corners. Anyway, the thinset has dried on the membrane and I discovered a couple of spots on two outside corners where I somehow missed getting thinset in. And I used a lot of thinset. Is there a way to fix that? Also, I had a little trouble getting the mortar texture just right when I applied to the tape so its kind of thick in some places. Should I sand this to make it smooth and flat?
You can still add more thinset to the kerdi wherever needed. Yes, you can (and should) sand that down to make it flat. It’ll make installation much easier.
Roger,
I wasn’t planning on using a membrane throughout the entire shower. Rather, I’m using the Oatley shower pan liner just for the shower pan mud bed area. However, I want to do a niche. If I use a membrane (whether leftover Oatley or Kerdi) only in the niche – it would seem that any water that would penetrate would terminate on the vertical, untreated cement board and thus this would be an unacceptable installation. Am I correct on this?
Thank you.
I recant my dumb question. I hadn’t thoroughly read your post where you point out that in lieu of Kerdi, you can use liquid, which I would imagine I should already plan to apply to my entire veritcal surface area anyway, even if I wasn’t doing a niche.
I recant my lecturing answer then.
The questions I answer are taken in order and did not see this one before I answered that one. If you have another one somewhere it should be answered shortly.
Hi Marc,
Any shower which does not utilize a barrier of some sort throughout the shower at least up to the shower head is incorrectly built and and unacceptable installation. Your scenario is correct – it will begin to collect on the vertical and begin to absorb into it.
Hi Roger,
) Would it be best for water drainage to bring the tile out ? Also , my daughter’d like
Great info as usual ! Thank you for providing this resource. I’ve got a niche question , is it just a matter of taste as to how I’d tile the top , bottom , and sides of the niche with regards to the tile extending out of the niche and overlapping the wall tile as they meet ? (sorry ’bout the run-on sentence
1″ mosaic tiles just in the niche so instead of using a 1/2″ notched trowel what would you recommend to keep the thin set from oozing up between the tiles? Thanks much. – Steve
Hey Steve,
I prefer the tile in the niche to be flush with the wall tile, but it is a personal choice. Overhanging shelves drip water, that bugs me.
I would use a 3/16 v-notch trowel for those mosaics.
Hey Roger.
Thanks much. I am confident and reassured now that you’ve given me wise advise.
This project is coming along very well and I want to get all of the details correct.
I understand it’s an optional thing but I’ll go with the Roger preference. Also 3/16ths
it is! I appreciate your expertise ! You do some fine work !
H i Roger
I was wondering how to build a row of glass mosaics out to the depth of my ceramic tiles. If I use thinset then I end up putting so much on that I can not get the glass to lay flat and even. Is there something I could use to give me some depth to start with? Thanks John
Hi John,
Yup, right here: Installing different thicknesses of tile
We’re redoing a bath and were told that if we used Hardi backer that we didn’t need to use Kerdi. We were told to use the mesh at the seams and we’d be fine. If I read your blog correctly, you are saying the shower is not waterproof and could just fall apart or become extremely moldy in 3 months?
Oy! Did I understand this correctly?
Hi Virginia,
Yes, you read that correctly. If the shower is not waterproofed it can fall apart of develop mold in three months.
You did, however, only understand part of it. Kerdi is not required. It is only one of about 20 (general) accepted methods of waterproofing a shower, the most basic of which is to simply have a moisture barrier behind your hardi. Read through this and it will give you the basic method of waterproofing: Preparing a shower wall for tile with cement backerboards.
You can also download my free waterproofing a shower pdf which will explain in detail the different methods.
Hi Roger,
My husband and I are doing some remodel in my mom’s house. We have found mold is several areas so the project has grown considerably. Currently we are putting in insulation and new floors in one of her bedrooms. Today while taking out the drywall in that room on a wall that is next to her bathroom I found moisture on the bottom of the drywall and also noticed that the back of the niche that she had installed when she had the bathroom redone seems to attached directly to the drywall in that adjoining bedroom. Is that correct? Logic tells me no but I am far from an expert on that.
Hi Nora,
I attach the back of niches to the adjoining wall all the time. I, however, use a topical membrane which means that neither substrate (the niche backer or the drywall in the other room) ever sees moisture. The moisture at the bottom of the drywall is NOT normal, and is a sign of an incorrectly built shower. Is the wall of the shower drywall as well?
Thank you Roger for getting back to me. The portion of the shower wall that has been covered with tile is concrete board but above the tile level is drywall to the ceiling.
Then it sounds like there isn’t a moisture barrier behind the concrete board. Is there plastic or roofing felt between the cement board and studs? If not then it will continue to get the surrounding structure wet. Concrete board is not waterproof, it is water stable. It won’t warp or fall apart when wet, but it will soak in moisture and retain it. That’s completely normal but there does need to be a barrier behind it to keep the water inside the shower and away from the studs and adjoining walls.
Roger,
What are your thoughts on the pre-fab plastic-like niches such as PreFormed? Any tips on sealing between the edges of these niches and the cement backerboard?
Also – I am replacing a plastic surround with a tiled shower above the tub. On the front side of the tub wall (where the shower head is) the plastic surround comes all the way out to a 90 corner (actually wraps around slightly). When peeling this back I can see where the drywall has been cut out to the corner – so if I put backerboard in all the way to the corner and tile to that corner with bullnose or a picture frame I will have the factory finished edge of the backerboard exposed to the room. Does that make sense? I don’t think I can use a traditional corner bead as it will lift the tile up. Should I just tile and then finish the drywall and edge of the backerboard with joint tape and joint compound?
Thanks,
Ian
Hi Ian,
Hate the prefabbed niches – strictly a personal thing, though. Nothing wrong with them and they work just fine. Most are sealed with just silicone.
A corner bead is 1/16′ thick, it should not lift your tile up any more than normal if you are using a correctly sized trowel (normally 3/16 x 3/16). The amount of thinset should more than compensate for that. You can also install the corner bead and float it out on the shower side with thinset to create your plane. If you do it after the fact use fiberglass mesh tape and thinset or joint compound you mix with water (not the pre-mixed wall mud, it’ll disintegrate).
Roger,
Thanks for the information – good stuff.
Can you give me a little more detail on the corner bead install? Should I use joint tape and compound on the drywall side and fiberglass tape and thinset on the backerboard side or are you saying I should use joint compound (the good stuff) on both sides?
Lastly – should I just use a tube of silicone and run that between the prefabbed niche and the backerboard? Should I run a coat of tape\thinset over it afterwards like the other joints?
Thanks again!
– Ian
Fiberglass mesh tape on all of it and either thinset or joint compound on all of it, either one. You can paint over thinset if you choose that route.
With the niche – do whatever the manufacturer says, they vary widely.
Thanks again, Roger. Your expertise has been invaluable.
When including a niche in a shower install – do you tile around the niche first to be sure everything lines up properly or do you take proper measurements and start further down the wall? I know it’s bad practice to start on the tub but I am unsure how far up is best practice.
Also, is it OK for my top row of tile to slightly overlap the drywall?
– Ian
Hey Ian,
I install everything from the bottom up. When I get to the niche I tile it as I’m moving up the wall. You can take your measurements whenever you want, the closer the tile is to the niche the better your layout will be. If you get your measurements exact you can just tile it all at once. The key is knowing where everything will be before you put the first piece of tile on the wall.
Can I use a moisture barrier over plywood then the Hardi board then tile for the floor of the shower?
NO. Why would you want to do that? (I mean other than the obvious ease of preparation) If you do it that way you’ll be replacing not only the shower floor in about three months, but likely half of the surrounding structure. Not a good idea.
I asked because that’s what they told me at Home Depot. I just wanted to be sure that I wasn’t crazy. Thanks.
By the way, I just happened on your site and you’re a hoot. But after reading all that niche prep, I think I’ll just by one that sits in the hole’……………
Aaah, gotcha. Yeah, you aren’t crazy – they are!
Hi, I love your website and have spent a couple of hours in preparation for a bathroom remodel. The plan is for a bathtub in a alcove, with 3 tiled walls around the tub. I plan on using plastic on the studs, then backerboard, for ease and cost control, but I would dearly love to have a niche or two. Your 4-part niche series does say it can be done with waterproofing liquids, but I have a few questions:
1. When I make the niche, it will mess up my plastic moisture barrier. What do I need to do in preparation for that? Do I staple and caulk the plastic, wrapped around, a little ways into the niche? Or right up to the edge? Or is that the making of a “mold sandwich?” I can’t figure the best transition of the plastic barrier and the niche edges.
2. Can I put drywall in the niche and use Kerdi in that spot only, blended onto the backerboard?
3. When I attach the backerboard in general, over the plastic-covered studs, do I need to use caulk or something as I put in the screws to keep it waterproof? That is probably such a basic question but I want to be sure I don’t botch anything.
Thanks so much for your help, and Happy New Year!
Hi Diana,
1. Cut the hole in the plastic the same size as the hole for your niche and silicone the plastic to the backside of the backerboard. The effect being that the silicone creates a dam around the niche so when water runs down the wall from above the nice (behind the backer, over the plastic) it will hit that bead of silicone and run down and around the niche, and continue down into the drain.
2. Nope, you want to use backerboard. Although water will not get into the niche a tiny bit may wick up the backerboard and into the backerboard inside the niche. While this amount is not enough to reach or do any damage to the studs, it will disintegrate drywall. It would also be best to have a bead of silicone between the backer on the wall and the backer in the niche. This prevents any wicking at all.
You can use kerdi over the backer inside the niche and carry it out onto the backer on the wall about two inches all the way around the niche. This won’t create any mold sandwich problems.
3. Nope, and not basic either.
As you screw in the fastener it will create a pucker in your barrier which essentially creates a different type of dam between the plastic and backer. Water will run around it rather than into it.
nice looking nice, I decided to give it a try… but I am not sure how to do the joints between the vertical and horizontal surfaces. I am told I have to use metal trim, which I find not very attractive.
I do not see such metal trim around your niche, so I am curious to know how you did your edges?
Hi Rene,
You do not have to use metal transitions or trims. Most of my niches are made with the horizontal piece of bullnose inside the niche simply resting on the vertical wall tile outside the niche.
I’m wanting to add one like your final picture with the 2 insets. do you just add a shelf/divider between a larger opening, or do you have to build a completely different insert? You didn’t really explain that part unless I missed it. Also, I was going to use the Kerdi as you recommended, but am only going to use it for the niche. Home depot has it only in 5″ strips which doesn’t cover the width. I don’t want to buy a huge roll to get a one piece layout as you had shown. for cost reasons. Is there a way I can use the 5″ strip Kerdi and overlap it? Or will I end up with leaks?
Thanks,
Beverly
Hey Beverly,
I simply placed a shelf at the appropriate height in a large niche to separate it. It’s just two pieces of tile (one cut wall tile and one piece of bullnose) placed (almost) in the center. What HD has is kerdi-band. You CAN use it for the niche as long as you overlap each piece two inches. It will be fine. A better option might be to call around to some contractors who use kerdi and see if one of them has a piece big enough that they’ll sell to you. I always have a load of extra pieces laying around.
Hi Roger,
– so we decided to “do the rest of this ourselves”. We survived our first bathroom floor fix and are now working on our master. We really appreciate your tips as we’d love to have niches in our shower….rather than those nasty wire things which hang off the shower head and generally slip and spill assorted and sundry bottles of liquid on my toes! 
I would like to make a niche with two shelves – one for shampoo articles and one for my rubber duckies (yes, I collect them too!). 
Thanks again for all your help!
Wanted to thank you for the insightful, understandable and yes, even playful explanation on how to create a professional “hole in my shower wall”. My husband and I are self building our retirement home and – after three plus years, are down to floor tile and showers! We think we may have met the “hack” you referred to in part 1
Best regards,
Debbie
Hey Debbie,
You are very welcome! If you need any help at all don’t hesitate to ask. I’ll usually answer when I’m sober.
That, by the way, has been since 2001 – but don’t tell anybody, it’ll ruin my nasty reputation!
Congrats Roger! I spent quite a bit of time last evening running through your FAQs. Did have one particular question and another request if you have this DIY listed somewhere (for a newbie, don’t want much do I?
Question: We bought this roll of fine mesh stuff that it says we should apply with a thin coat of mortar to the seams and thus join the hardibacker. Several folks have told us this is a waste of time as our cement board is down on quality subflooring. We are installing natural marble with a nice pattern (spent some time matching those out) so I am inclined to add the mesh. Thoughts??
Request: Saw your beautiful picture of the shower with the triangle ledges in the corners…I would LOVE to add a couple of those around my garden tub as it will have the same travertine finish as our open shower. Is there an article on how those are installed or at least brackets so I can order glass later? Gotta have something to hold the duckies and candles ya know!
Thanks so much!! Time to hit the showers – with waterproofing and cement board!
Have a great day sir!
Deb & Doug
Hi Debbie,
Yes, you should use the mesh. What it does is create a monolithic structure out of separate sheets of backer on the floor so that any movement is transferred over the entire installation. It also creates a substrate which moves all in the same direction rather than each sheet moving differently.
The triangle shelves are fairly simple. Read through this and it describes how I install them: How to build a corner shelf.
Hey Roger,
Long story short-bought house, tiles in niche started to buckle after about a month, got estimate for floor and niche from tilesetter, removed buckled tiles, tilesetter no-showed for the job. Had another tilesetter do the floor but did not do the niche. To make matters worse, the entire bathroom is done in subway style tiles which have been discontinued (there are tons of very similar ones, but none that are the exact shade or exact same size) which meant I had to carefully sand the grout and peel the cement off each tile. I don’t think it’s reasonable to put the kerdi on because I would have to take them off all around the niche and I don’t want to risk breaking a tile and I have a bad feeling they were mounted straight onto the drywall. Do you have any suggestions for a guy who is generally quite inept but has to deal with a tiling issue that no tilesetter wants to?
Hey Archie,
Get some redgard and paint the inside of that niche to keep water out of the substrate. It buckled likely because water was being soaked up back in the substrate or wall cavity and started to swell. If you replace the drywall with backerboard and redgard it you’ll be fine.
Hey Roger! Thanks for this very educational and entertaining article. I’d very much like a niche for my rubber ducky… What is your thought on “ready to tile” niches you can buy at Home depot? Is that for fakes? Or is it a good product to use if the dimensions match your tile choice?
Let me know your thoughts
Julie
Hi Julie,
It’s for fakes! Hacks, rookies, wannabe’s… Just kidding.
They work just fine provided they fit your particular tile and your particular layout. That NEVER happens with my showers so I don’t even try anymore. They do work well, though.
Pretty sure it won’t match the tile exactly…. so I’ll probably end up doing the DIY method following your instructions. (Minus the beer)
Julie
Sorry if this seems a bit stupid but in your above diagram where you did a great job of showing how to measure and drew the 2″ and 5″ lines. I am unclear of the cuts. I get and understand cutting the 2 inch section from each corner to be applied later but I am unclear if you cut both sides of the 5 inch. Secondly does the 5 inch cut section remain inside the niche?
Last question is I was planning to put durock inside the niche on top of the kerdi. Is this a bad idea?
Not stupid at all – I do it every day, I’m just used to it. The dotted lines in the lower left of that corner are the only lines that get cut. Repeat those cuts in all four corners. The inside 3″ of the 5″ sections go inside the niche – they are the sides of the niche. The outer 2″ lap outside the niche to waterproof the edges.
Why do you want to put durock inside the niche? No real reason to, the tile is installed right to the kerdi. If you need more layers to get to the right size just add them all before installing the kerdi.
My Kerdi doesn’t stick! I have done some tests with thinset on scrap pieces of drywall. The thinset sticks fine to the drywall, but the Kerdi can be pulled off the thinset quite easily.I have tried this after approximately 18-20 hours and the thinset is still damp under where the Kerdi was. Do I just have to let it dry longer? I live in a dry climate.
Hey Allan,
Your kerdi is sticking just fine – quit pulling on it.
If you want a demonstration of the forces actually acting on the kerdi after it is installed on the wall test it on a piece of drywall, let the thinset cure for 24 hours, then grab one end of it and try to pull it off the edge of the drywall. In other words – pull it off across the drywall. The force acting on the wall is actually sheer force – in-plane – not pulling out away from the wall but rather down it. If it’s still damp after 24 hours it’s because you’ve used a modified thinset – let it cure about 72 hours if you’re concerned about that aspect – or use unmodified thinset.
Hello Roger, I need your expertise yet again. I get mixed answers on the following and wonder if you could share your experience:
1. Install floor tile to 1/8″ off the wall;
2. Suspend wall tile an 1/8″ off the floor tile in case of structural movement;
3. Caulk the gap;
4. When installing tile on concrete backer board (BB) wipe the BB with a wringed sponge and then apply mortar and then tile.
I appreciate your expertise very much. Thank you. Arthur.
Hey Arthur,
1. Yes. But I do 1/16″
2. See above.
3. Yes, silicone is better than caulk
4. Yes. Backerboard sucks moisture out of thinset like a sponge thus weakening the bond. Wiping it down compensates for this.