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.
I have installed 2 tile redi niches in one of my showers, but they are about 3.5 inches deep. I haven’t selected tile yet, but all the bull nose I have seen are only 3 inches wide. How would you tile these niches?
Hey Tyrel,
You’ll need to add 1/2 strips of tile in the back behind the bullnose. They don’t make pre-made niches for the tile size – they make them to fit the wall cavity. Another reason I don’t like them. You can also cut 3 1/2″ field tile to tile the niches, then use the bullnose on the outside to frame them. You can also use some type of natural stone which can be cut down to 3 1/2″ and bullnosed to fit.
Roger
In the “Finished” picture of the niche, it appears that there is a space between the tile on the right and the edge of the niche that is larger than the width of the grout line. i.e. the edge of the tile is not flush with the edge of the niche. Is that intentional? If so, why? If not, what do you do to make this group line consistent with those in the adjoining tiles?
I’m taking a big breath and cutting the hole for my niche in my beautiful Kerdi today.
Thanks!
Hey Larry,
That is actually due to the camera angle – the completed niche lines up perfectly with the grout lines. You can see it with the tile installed here. When measuring for your niche you simply need to take all the layers into consideration and make sure you are lined up perfectly – no pressure.
If you do cut it too wide you can always build it out. Just make sure it’s wide enough or you will run into the problem that you mentioned – and there really is no way to fix that short of cutting it out and starting over.
Hi Roger. Great site with lots of helpful tips and keeping it light with humor is a major plus (for me).
I am in the middle of retiling my upstairs bathroom. The builder’s work (as I quickly discovered) is a nightmare – uneven studs and studs that are off from an adjacent member by as much as 1/2 inch. The floor had a 1/4 crown in middle of the bathroom. I ended up gutting almost an entire bathroom.
I have three questions for you (actually I have a lot more):
1. Will a 1/4 lathe glued and nailed to studs be strong enough to support the 1/2″ cement board?
2. OK to use Safe&Sound behind cement board and 4mil plastic?
3. How do you handle the vapor barrier around the pipes and shower valve? Do you use a special tape to secure plastic barrier to the shower / tub spouts and the valve opening itself. Thank you!
Hey Arthur,
1. Not sure I’m understanding what you’re asking. Normally the cement board is screwed directly to the studs – no need for metal lath at all so long as your studs are 16″ o.c. You can shim them out to make it level and straight in-plane before attaching the boards. Perhaps I’m just misunderstanding?
2. Safe & Sound is fine behind your shower walls. (That is a noise-reduction insulation, for anyone else reading)
3. Cut the barrier as closely as you can around the pipes and just use regular silicone to attach the barrier to the pipes / spouts. Around the shower valve cut your opening however large you need it and place one continuous bead of silicone all the way around the outside of that cut before placing the backer board against it. This creates a full ring around your valve so when water runs down the wall behind the tile it will reach the silicone, run around it, and continue down into the drain without entering the wall cavity. Your escutcheon (cover plate) should have a foam ring around the back of it to prevent water from entering from the front.
Roger, Thank You for your reply. By lath I meant 1/4″ strips of wood to shim out the studs. One other thing perplexes me and that is the Kohler’s K304 shower valve installation. But I let my plumber worry about it. There’s only so much that a mortal DIYer can do.
Oh, I assumed lath meant the metal mesh we use – you’re talking old-school lath.
Yes, you can use lath to shim out the walls. Only so much a pro can do too! I have my plumber and electrician on speed dial. I do what I do and let them do what they do. Best way to do it. Dooby-dooby-doo! (Sorry, had Sinatra going through my head there for a sec…)
Floor Elf, (name suits you, helpful yet mischievous)
Just Redgarded my niches but realized, thanks to your site, that I’ll need to buy a few bullnoses to make the edge look nice and in order to avoid that sliver of tile, I’ll need to add another 1/2 thick panel of backerboard to the niche backwall. Since I’ve already got the membrane on, I don’t want to reapply over the extra panel do I? Thanks!
Hey Aaron,
You do not need to waterproof the piece you put in the back of the niche if you do it after you’ve waterproofed provided the material you are using is water stable – like durock or another cement board. As long as it won’t be negatively affected by water then there is no need to waterproof over it.
I’m living a nightmare. I know just enough to “think” my remodeler is not doing my shower properly. Let me know what you think. 1) He nailed the cement board to the studs – not screws. 2) He only put a thin layer of red barrier. 2) After doing this, he ealized the floor was off plumb and added cement board in various areas of the wall to level. Then he used some sort of white mixture over that. However, the walls now are not smooth. 3) He nailed the top of the curb vinyl liner to the 2 x 4s. Then he added metal lathe – then he mudded the top and sides without smoothing it out. It’s more than 5″ wide in it’s rough lumpy uneven state.. He has already tiled the floor and it is slightly uneven because he says the wall weren’t plumb. He still has to make the opening for the soap dish and install a premade wall shampoo niche. Scares the heck out of me as to how he will do this. Then tile. I’m thinking of letting him go because I have no confidence in what he is doing and am afraid of what is yet to come. Any advice? PS: He’s a really nice man, but….
Hi Lily,
It depends entirely on what type of shower substrate he is fabricating. Galvanized nails are an accepted fastener for cement backerboard. If he is building a ‘mud’ shower then everything you’ve seen may just be the preparation for it. A couple of things you’ve said confuse me a bit and a couple may be interpreted in different manners. When all is said and done, before he puts a piece of tile on that wall, he should have a completely flat, waterproof wall. If it is not that, then something is definitely wrong.
Hi Roger,
How do I keep plastic vapor barrier incorporated into niche and then put cement board and red guard? Do I need vapor barrier if I am redguarding after cement board in.
Also do I use screws to put cement board into wood of niche or mastic. Your directions with kerdi are great but I am doing it with plastic barrier and redguard.
Thanks ,
Dick
Forgot you were using the redgard. Just silicone the vapor barrier on the wall to the backside of the backer around the niche, then redgard the inside. No need for a vapor barrier with the redgard. Yes, use the same screws you used for the walls inside the niche too.
I found your site while looking for the name of the bright orange stuff, now known as Kerdi
your site is AWESOME! So glad I found it before attemting anything crazy, I’m in the planning stage of redoing my master bath, and look forward to bugging you wityh lots of questions, j/k (hopefully) I saw Kerdi on a home show and wanted to use it, but now my mind is flooded with possibilities. Have you ever done a roman tub using Kerdi? I have a 59 x 39 3/4 area, I have looked at tubs but I will lose some space if I buy one, but making one…. is that even a possiblity? Sorry if you have this on the site somewhere, I read about the niche cause that is a big reason for wanting to redo the bath, so glad I found you! Oh and another question, my ceilings are faulted the highest point being over the shower, would you recommend going all the way up? if not how do you transition from tile to drywall? (The ceiling is about 12′ 7″)
Thank you for this awesome site!`
Hey Tonantzin,
Let the professionals attempt the crazy stuff – like me.
A roman tub is a VERY exacting and very difficult fabrication and installation. Yes, it can be done with kerdi but it really, really shouldn’t be done by someone not experienced with them. The first one I built I was basically held by the hand a led through it step-by-step, and still felt like I was out of my league. It IS NOT an easy installation. I would absolutely not recommend it.
I’m a frickin’ barrel of sunshine, aren’t I?
I always tile to the ceiling if I have a choice, I think it looks better. You can also transition with bullnose or a metal trim such as Schluter Rondec. Or, if you like the crazy stuff, you can get all fancy-ass like I did with a Slate shower installation. The metal on the left side of that is the Rondec, by the way. That particular ceiling is vaulted to about 13 feet as well.
Well Sunshine I’m glad I asked you first! It was just an idea, I looked up roman tubs and maybe that’s not exactly what I ment, just a tub/shower built of tile, in an elcove. Like how I made it sound easier? I’m trying to get you to say ‘go for it” but I appreciate your honest answer, if I take your advice is another story,
if I could find a tub the size I want then I would be happy to follow your advice and tile the shower suround with a niche 
Seperate question here, tiling up to the ceiling, how high up the wall would you go with the Kerdi? There is also a stupid half circle window with a slider under it, in lew of a vent, it’s higher then the shower head (6’) I’d likely tile that too, but how does tiling verticly in an arch work? Sounds like a pain, but I know if I tiled up the wall it would have to be done.
P.S. the link there for the slate shower didn’t work
Sorry, still not easier.
The kerdi has to go at least to right above the shower head. tiling vertically in an arch is a pain. There’s two different ways it can be done. Photos 10 and 11 on this page (9 as well, but difficult to see) Tiling a niche.
The photo for the slate shower should be working now, operator error (me) – sorry.
If I use 4mil plastic under Hardibacker, how do I waterproof my niche? It seems like it would be tough to put plastic up, hardibacker up, start tiling, and then cut a niche in the hardibacker with straight edges. Do I need to frame my niche first, then cut a piece of plastic similar to how you cut the Kerdi, put that in the niche with the tabs siliconed under the plastic already stapled up and then put all the hardibacker up? Do I still need a topical after that? As you can tell I’m either thoroughly confused or drunk on all the chocolate milk I’ve had today.
Hey Bill,
That is exactly what you do. Pre-build your niche in the wall and silicone the overlaps of the barrier. It is always best to have a topical membrane for the shower niche but if you don’t that’s the way you do it. If you layout everything really well you should be able to get it built in the exact spot. Make sure the barrier on the wall overlaps the niche barrier on the top and sides of the niche, and the niche barrier overlaps the wall barrier on the bottom. If you use a topical membrane in your niche do not install the regular membrane behind your niche. Just silicone the wall barrier to the hardibacker all the way around the niche, then use your topical membrane inside the niche.
Did I just confuse you more? I’ve had a bit of chocolate milk myself today.
Nope, I think I’ve got it now. I can do a traditional method on everything including siliconing the barrier into the framed niche before adding hardibacker or I can do traditional method everywhere except the niche and use a topical membrane in the niche and a border around it.
I have a little bit of access to the back of where my niche will be so I also decided to go ahead and add my hardibacker to the lower half of that wall and tile up to get an idea of my grout lines and then add in my niche, hardibacker the top, tape, thinset, and tile the rest. That way it will have that nice planned out finished look. Make sense?
Hey Bill,
Sounds good. If I can help with anything else don’t hesitate to ask.
Do you have to wait for the thinset under the niche Kerdi layer to dry before continuing to tile?
Hey Kris,
Nope, you can tile anything you install kerdi (or ditra) on immediately – no need to wait. The only things I wait for are horizontal installations – like tile ceilings. The top of your niche is fine, though.
Hi Roger, I installed DensShield in my tub/shower surround and plan to tile with porcelain tile, and along the middle I am installing a glass border (Listello) around the tub where I plan to separate 12×12 below tiles with 6×6 above. I plan on using Laticrete thinset however not sure which one to use the platinum 254 or 255. The salesman at the tilestore is recommending the 255. However I am not totally convinced in his knowledge because when I mentioned that I am installing a border of glass he looked at me puzzled so I said I am installing a Listello figuring a tile guy at a tile store would know that term, he then said oh yea we should have that tile in stock, we have many Italian tiles on hand….. This is from a all tile and flooring store… So I thought I would get a 2nd opinion.
In any event it should be unmodified going on the dehshield? Thanks for your help again…
Hey Bill,
The 254 is the platinum, and it’s great stuff. The 255 is the multimax and it’s greater stuff.
The 254 will work fine for what you’ve described, it works well with glass also. The 255 also works well with everything and it’s ‘non-sag’ which means that if you spread it and press the tile onto the middle of the wall without any support from tiles below it won’t slide down the wall – it’ll stay where you put it. That is great stuff to work with when you’re using large tiles or need to start in the middle of a wall or something similar. If you use the 255 you can start at the top of the wall and work down. If you aren’t concerned with that use the 254.
Denshield does not require unmodified thinset. Both you’ve mentioned are modified – it’s not a problem. I think I’d be finding a new tile store.
‘Yeah, we have italian tiles…’ 
I am using backerboard and building a niche, if I follow your directions what happens above the niche. I mean will water run down my vapor barrior and pool on top of nich? How do you continue your vapor barrier behind and around the niche or do you just cut it away ?
Hey Mike,
Cut the opening for your niche out of your vapor barrier then cut or fold an additional piece of your vapor barrier just like the piece of kerdi for the niche. The only difference is that the plastic will go behind the backerboard rather than on the face of it, the top flap of the plastic for the niche goes behind the barrier on the wall as do the side flaps, and you will use silicone to attach that niche piece to the barrier on the wall. Once sealed up tight water will run down and either around your niche or into the top and out of the bottom on the face of your barrier.
Hey,
Great site! Ive learned so much. I am waterproofing my niche with roofing paper and followed the same pattern as you did in the example with kerdi. Awsome pics and directions! One question: When tucking the flaps in, do you put thinset or anything under the flaps or just thinset on top to hold them in place until the durock install? Thanks for your help! Ken
Hey Ken,
You want thinset beneath the flaps as well – it assists in locking those two layers together and makes capillary action much less likely between them (water can’t get in). Do make sure the bottom of your niche is sloped correctly so water doesn’t sit there and test that theory out. :Do It’s true, but no need for a pond in the bottom of your niche, eh?
Okay, I think I know the answer to this but I respect your advice. I thought I was ready to tile my shower as my bathroom walls are all sheetrocked and ready for paint. My shower is Durocked with plastic behind it. The plumber put in the shower pan before I did the sloped floor. He told me thats how its done and I didnt know any better. Now I realize I should have sloped the floor, then shower pan, then more floor. Today I had a remodeler over to the house, and while he was here…I asked him to look at the job I was doing and he asked how the pan was done. I told him and he told me that a flat shower pan will hold water, contributing to mold. Makes sense to me. I had read this after I poured the floor. As this is a basement shower that will get very little use, I was prepared to roll with it. My visitor told me I should put a waterproof membrane on the floor, about 2 feet up walls and around niches. He recommended a RedGuard type product. I have read not to use a waterproof membrane if there is plastic behind the Durock. What do you say? Thanks greatly!!!!
Hey Ken,
You already know I’m gonna suggest you remove that current base and rebuild it correctly, right?
The flat liner is a mold factory. It will never flush that water and replace it with fresh. You do not want to place a liquid membrane over your current base – it will trap moisture between the two with no way to dissipate. Same on the walls with the plastic barrier behind the backer.
Take out what you currently have, fabricate a pre-slope, install your liner, and fabricate your top slope, then tile away. I’ll send guedo after your plumber.
Roger-
Thanks for the response.
Derk
Roger-
In a previous post from Mike on 01-18 suggested that he put cement board down prior to a sloped mud bed. I have 3/4 plywood base with a single piece of 3/4 plywood on top of that (the 3/4 subfloor had to be reinforced due to sagging, bowed joists, etc.). I was planing on installing a sloped mortar bed/liner/another sloped mortar bed on top of that. This is the first I’ve heard of a a cementious backer board prior to the first sloped mortar bed. Your reply is appreciated.
Derk
Hey Derk,
I believe you may have misread that – I did not advise him to do that at all – he did it before he posted his question. There is no need for the backerboard beneath the mudbed. It doesn’t hurt anything if it’s already in place, but it’s not necessary at all. Your floor is just fine.
Hi Roger, I am redoing my bathroom, replacing the tub and surrounding walls with porcelain tile and instead of cement board I am using DensShield Tile Backer by Georgia Pacific, everything I read it sounds superior to cement board. According to specs the material has a vapor barrier built into it and no additional barrier is needed. Since this is going on an outside facing wall and that wall is insulated with fiberglass but damaged and I am going to replace it, I assume I have to replace it with unfaced fiberglass so as I don’t have 2 vapor barriers in place? I also talked to a rep at Georgia Pacific asking him if Kerdi or Laticrete Hydro Ban would be required or would be overkill. He stated that if I purchased it go ahead and use as it wouldn’t hurt it but if I didn’t then save my money as it would be overkill, that DensShield has a lifetime warranty against failure from water damage. Have you heard of this product and if so what are your thoughts of using or not using additional protection. Also could you recommend a caulk that doesn’t mold up over time, seems no matter what I tried in my old tub area it would develop surface mold after a while. Also what size caulking backing do you use in the flange area below the backer board and then you caulk right over this backer rod, You just use the typical grey backer rod. I assume you use this backing rod just to take up area so as not to fill in so much with caulk or is there another reason for the rod….? Sorry for all the questions. I appreciate your site very much as I do the humor.
Hey Bill,
I actually use densshield from time to time – it’s quick and easy and a very good product if installed correctly. Make sure you use 100% silicone between all the sheets, at all the corners, and at all the screw holes since you’re penetrating the barrier. I usually mark my studs on the front of the board, put a dab of silicone where I want the screws, and screw right through the dab. This seals the penetration as you screw it in. Hydroban or kerdi is overkill – it won’t hurt, but no real reason to use it too. I don’t think the densshield warranty would stand if you used an additional product as well, but I’m not positive about that.
I do just use the regular gray backing rod when I need it. If it’s too big I’ll get a smaller one or simply slice that one in half. It’s just there to fill space – that’s it. And yes, use unfaced insulation behind the densshield.
I use 100% silicone in all my joints and changes of plane. Provided your wall is properly constructed and you leave weep holes at the bottom of your walls mold will not be a problem. If you can find one with microban in it that always helps. Laticrete’s Latisil is great stuff and you can get it to match your grout.
Hi Roger, thanks for the reply, I appreciate your follow up. I do have a rebuttal to your follow up..lol You mention having weep holes in the bottom of my walls to help prevent mold, I understand what weep holes are and the importance on brick structures, however I have a frame house with vinyl siding and am certain there probably are not weep holes in the building. I have total access to the inside structure as I tore out all the old cement boards and drywall which I will replace along with the insulation, however I am hoping you can clarify the weep hole comment, is this for brick only homes? or with having the walls open having total inside access is there something I should do besides replacing the insulation with paperless insulation as stated previously because of the DensShield? I recently had the entire house resided and had them install 1 inch extruded polystyrene insulation around the home for additional insulation rather then 1/8 fanfold insulation, so that is what I have as far as exterior insulation. But I am a little concerned about these weep holes. I want to keep my mold and mildew down as much as possible so now is the time to make and changes. Thanks again Bill.
Hey Bill,
I think you’re overthinking the whole weep hole thing.
Every shower installation needs to be able to properly drain moisture that gets behind the tile. It has nothing at all to do with the exterior of the house or any other method of construction in the house itself – only with the shower construction. Read through this: Weep holes in tile installations. If you have any questions let me know.
Hey, I really like the humor! It helps relieve the extreme stress I am experiencing while I try to do this stuff. I’m doing a shower stall in my second bathroom. I put in 3/4 inch plywood subfloor, then 1/2 inch cement board. I then put in a sloped mortar bed/liner/another sloped mortar bed. I have since tiled the shower floor. Was I supposed to do additional waterproofing over the second mortar bed? Do I need a moisture barrier behind backerboard walls? Do I need to waterproof the outside of the backerboard? Or do I just tile over the backerboard? I’m hoping you can get me through the final stages. I’m also hoping I don’t have to start anything over. Thanks.
Hey Mike,
You don’t need to start anything over at all – your shower floor is properly constructed as it is. Just install the tile directly to the top mud bed. If you are using backerboard as your wall substrate you need either a moisture barrier behind it which overlaps your floor liner (like roofing shingles so the water will run into the liner in the floor) or you need a topical membrane on the face of it. These are products like liquids (redgard, hydroban, etc.) or sheet membranes such as kerdi. You only want the barrier behind or the membrane on the face – never both.
Sounds like you’re right on track.
Hi Roger, I really appreciate that you sharing your genius, us weekend warriors are smart people with little knowledge (of the jobs we tackle). So I am currently one step before Mike, have the shower base in and haven’t tiled. My plan was to apply a liquid membrane to the base before I install the tile. Needed or not? Also, I may (likely) be a glutton for punishment, but i am installing wet cement for tile base for the walls and the adjacent jacuzzi deck. I have the structure solidly (over) built, covered with tar paper and diamond lath and will be applying a 5:1 portland:sand mix. I am absolutely planning to apply a water proofing membrane to the shower walls, seat and jacuzzi deck areas. Thanks for your time.
Hi Clay,
If you do not have a pvc or cpe waterproof liner in your shower base then yes, you can install a liquid membrane. If you already have that liner installed then no, do not add an additional waterproof membrane to your base. Have fun with the mud work!
Roger, I’m good with the PVC liner and the shower pan is ready for tile. Your suggestion to “have fun” was prophetic. Yesterday was a long day of applying wall mud (Quikrete Sand Mix) on the area around where the jacuzzi will be placed. I struggled with applying the mud to vertical surfaces more than 20″ high as the mud was separating from the diamond lathe. As I haven’t started the shower walls, (much taller than 20″) I thought this may be an appropriate time get some expert advise. Let me tell you what preparation I have completed. I have tar paper stapled to the studs (pulled pretty flat between studs) and the diamond lathe is nailed to stud (the orientation is correct so that it holds the mud). I used a 1/2″ spacer (strip of plywood) to help keep the thickness even and match the drywall thickness. I am really guessing on the water content in the mud mix. Too dry and the mortar doesn’t hold together, too wet and it droops or worse yet separates from the lathe. Should I use a different motar mix? Also, should there be a space between the diamond lathe and the tar paper, somewhere for the mud to good? I’m hoping that I just have something basic in the setup or materials that is wrong. Suggestions?
PS Sorry my questions and the discussion is a long ways from building a niche.
Hey Clay,
If you’re using straight sand and topping mix that’s your problem. Your wet mud (what you are attempting) should be mixed at a 5:1:1 ratio of sand, portland, and lime. With the topping mix (at 3:1) you need to add 30 lbs of sand and 15 lbs of lime to each bag. That will make it much more workable and the lime makes it sticky to it doesn’t slide off vertical surfaces. You still need to pack it and screed correctly, but starting with a proper mix helps tremendously. The paper should be right against the lath – the mud grabs only onto the lath – it doesn’t need anyplace else to go. Just a basic mix problem – that should solve most of it for you.
Of course you haven’t truly experienced mudding a wall until said wall has slid off and filled your boots – that’s fun.
Hey Ridger,
I am planning on redoing my bathroom this winter & read about the Kerdi you use , if you use Kerdi then no need to use Redgaro or Laticrete? with Kerdi do I need a mositur barrier on the wall behind? Whats you opion on using Redgaro & Laticrete they seem to be like less work applying b/c you just paint them on instead of say Kerdi cutting & sticking? But how reliable & water proofing are they? Any suggusetions???
Hey Bob,
If you use kerdi you do not need anything else – moisture barrier, redgard or laticrete. It’s simply drywall with the kerdi over it then the tile is installed directly to it.
Liquid waterproofing membranes are less work and easier to apply. They are very reliable as long as you get enough coats on it to reach the proper thickness (about as thick as a credit card). If you use liquid waterproofing on your floor you also need fabric reinforcement around the drain and at the changes of plane. They are reliable enough to waterproof a shower.
The reason I rarely use them is simply due to the amount of time between coats and allowing it to cure. Liquids take me triple the time that kerdi does. (For most people that is not the case – kerdi would take longer).
Thanks for your input your the man! I think I have the time so I will use the liquid water proofing system I just need to do the wall & make a nichie like you have on your site…I will keep you posted if I have any more questions!
Hello Roger
for the shelves, do you put anything under the tile, or is it just the tile that rests on the tiles at the side of the niche? I have 4 x 4 tiles, I can’t find matching larger tiles. I’ve been looking to try and find a metal strapping to use – but everyone looks at me like I’m crazy!
Any suggestions? Thanks for this GREAT site!
Hi Mary,
Yes, it is just the tiles on the side that the shelf is resting on. With 4×4’s you can do one of two things:
1) Get some epoxy and epoxy some tiles back to back and offset them. That means cut one tile in half and lay it on the table shiny side down with a full 4 inch tile next to it shiny side down, and continue to lay tiles shiny side down until you get the width of the shelf you need. Then take a full tile and place it on top of the 1/2 tile shiny side up. Then continue to do that until you reach the end. Once you have the length you need just epoxy those tiles back to back, let it set up, then install it as I have with the large tiles. The offset tile (where the 1/2 tile and the next tile meet) is covered with a full tile so this alternating offset will give you enough strength to use it as a shelf (when supported on 3 sides inside the niche). Did I just confuse you?
2) A more simple alternative is to get a length of stainless steel and epoxy your tile on top of it. The stainless will not create any rust or other problems and will give you more than enough strength when supported on 3 sides by the side tiles in the niche.
Any type of strapping won’t really work. It will only add strength to the area above the strip and will not leave the entire shelf locked in and supported by the surrounding tile. It will eventually start to sag on you. Good idea – I even tried it once – that’s why I say it won’t work.
If you choose the stainless route you will probably need to have someone cut it for you – it’s very, very difficult. The epoxied offset tiles will give you plenty of support, though.
Totally understand! THANKS. It’s a lot of time to do these (for us newbies)- BUT will looks soooo much better than those wire corner racks or the wire hang over the shower head shelves! The plus to the epoxy is that the underside of the shelve will look good too. One of the shelves will be up a bit high in both my niches. Too bad doing the main bath first; but my basement one will benifit from this.
“Your tub should be installed first, then the cement board should go down to the top of the flange on the tub. Your waterproofing then will go down the board, over the tub flange, and end at the top of the tub ‘deck’ – the horizontal portion around your tub. “Ok I understand this; what do you do with the space between the cement board and the tub? there is a space there that needs something to support the tiles. Thanks for all your great information here!
FYI I’m using 4″ tiles.
Hey Mary,
Well, that’s a loaded question.
Let me tell you why – when a tub is correctly (technically) installed it should be done so that the vertical portion of the flange will set flush with the finished wall substrate. That simply means that the vertical portion of that flange will be even with the wall and support the back of the bottom portion of the tile – without thinset. The tile should only rest against it, not be adhered to it. That part is a movement issue, the acrylic will move at different rates than your tile substrate on the wall. If adhered to the acrylic also it may crack your tiles.
But we both know that installation – with the flush flange – rarely happens in new construction and never (that I’ve seen unless I do it myself) in remodels. So as long as you don’t tell the tile police I’ll tell you what I do with that space – nothing.
The vertical open space between the bottom of your backerboard and the tub should be no more than about an inch or so. This means that, with 4″ tiles, 3/4 of your tile is fully supported. No one ever walks on that tile and with the 3-1 ratio of adhered tile in that application it would take a hell of a lot of torque to bust it or otherwise compromise one of those tiles.
So long as your moisture barrier behind your backerboard or your topical membrane is over the front of that vertical flange then all moisture will go down into the tub. Depending on the layout of the tub you may want to fill that area with silicone but whatever you use needs to be a waterproof or moisture stable product – such as a combination of caulking backer-rod and silicone. With any method you do not want to adhere the tile to the acrylic of the tub as well. Also make certain that you leave a 1/16″ or so space between the bottom of the tile and the tub and caulk that in. This allows for that different movement between the two materials as well.
Thanks for the info on how to build a niche. I was wondering when tiling a tub/ shower surround how far down does the cement board go. does it rest over the tile flange on the tub? does it go to the floor behind the tub? When I waterproof do I waterproof the the entire area before I install the tub Thanks for your help.
Hi Heather,
Your tub should be installed first, then the cement board should go down to the top of the flange on the tub. Your waterproofing then will go down the board, over the tub flange, and end at the top of the tub ‘deck’ – the horizontal portion around your tub. The effect you want to achieve is to have all the water run down the waterproofing and into the tub. If, after you waterproof, you were to spray a hose into your shower all the water should end up inside the tub.
Sorry Roger, I have one more question – I looked around on your site but I couldn’t find the answer – when tiling a shower which comes first the chicken or the egg, oh wait that’s not it – which get tiled first the floor or the walls? I have always done the floors first, but I have only done 2 showers and you have done countless showers so I would like your recommendation.
Thanks, Elaine
Hey Elaine,
I usually do the floors first as well. That way I can get an exact layout on the walls with minimal guesswork. (There’s always guesswork) You can do either, though. I have done it both ways and simply prefer to do all the waterproofing and floor first then I can concentrate on the walls, design, layout, etc. It also eliminates the possibility of messing up your mud bed by tromping all over it. Once it’s set – it’s done. No need to worry. (Just make sure it’s set before tromping all over it.
)
when you say make sure the floor is all set before tromping all over it, does that include all the tile and grout? In other words do you completely finish the floor before moving to the walls?
Hey Brent,
If you choose to do it that way then yes, tile it first and let that cure – grout is optional. You can do it in any order you want, just be sure to always protect the floor of the shower as you are working over it. After it’s tiled it is much more durable than only the mud bed. Both should be protected, but an uncovered mud bed will take a lot less abuse before it is compromised.
Thanks
Thank you so much for posting these directions on how to build a niche – this will save me some money on a prefabbed one. I loved all of the funny comments too! One question (since you are very knowledgeable), I am adding grab bars in my shower, should anything be done about the screws that hold the grab bars on, or do I try caulking behind the twist covers so water doesn’t penetrate behind the tile? Thanks so much for your help!
Elaine
Hi there Elaine,
Before you turn your screws into the wall fill the hole for the screw with 100% silicone. This will entirely seal the screw as it is turned into the wall. You can also use silicone behind the escutcheon (the covers) if you would like. If you have not yet installed the wall substrate onto the studs you should also place a 2 x 12 between the studs where you are placing your grab bar. You can then screw the grab bar directly into a stud or solid backing without worrying about anchors.
Have a great evening and keep sewing!
Thanks Roger, the silicone sounds like the perfect solution to seal up the screw holes – duh, not sure why I didn’t think of this as that is what I did when I lag bolted a 2 x 12 bond against the house for a deck that I built (of course that was 4 years ago). As you can see I am paranoid about water and mold. And yes I have already put blocking in for the grab bars, but thanks for mentioning it – I do tend to forget some of the most obvious things sometimes.
Thanks again for all of your help!
I have a newly installed bathroom with a walk in shower. He insisted in using tile adhesive, there is no kerdi. Am I in trouble with this shower? Should I not use it? I do see some cracking in the caulk in the corners and on the niche.
Thanks for your informed reply
Hi Lin,
I dunno, I can’t see it from here.
Sorry.
I need a bit more information about your particular installation to be able to answer that question effectively. When you say ’tile adhesive’ do you mean mastic or pre-mixed? Was the same adhesive used under the floor tile? Is there floor tile? What is the substrate behind the tile – drywall, greenboard, cement backerboard…? Cracking in the caulk at the corners could mean the shower is doomed to fail – or it could simply mean he doesn’t know how to caulk.
I need a little more info please…
Hi Roger, me again.I’ve redgarded the shower and am ready to tile. My ? is when tileing the niche and bench does the tile butt up to the wall on the top of the bench seat and inside shelf of niche? Then the piece on the wall above you leave the space for the grout line? Or do you leave a space behind the tile shelf piece (and bench) and slide the wall tile down in there?Does that make sense? Thanks Lana
Hey Lana,
I always set vertical tile on top of horizontal tile. That way water will naturally flow down from the top to the bottom without getting trapped anywhere or slowing in places like a grout line. Think of it like having the tile in without grout and having the water flow from the top to the bottom without getting trapped in a grout line.
I also do not leave a full grout line on changes of plane. I will usually only leave 1/16″ or less. Not butted but very close. (I do believe that’s the first time I’ve typed ‘but’ right after ‘butted’ and did not insinuate ass anywhere in the context.) You also want to leave a very small gap between the tile and the wall – don’t butt it against the wall. The tile will not expand but the framing behind your wall has micro-movements over time. You never want to butt the end of a tile directly against your wall.
Wow, that’s a lot of butts in one reply.
Love the humor,needed a good laugh! Thanks so much for all the help. People like me need all the help they can get! Thanks ,Lana
Hello! This is great! Can I ask you ,If we have cement board up already ,is it necessary to waterproof the whole shower with redgard or kerdi? Or can we just do our bench seat and niche? We have a moisture barrier behind the cementboard. Thank you! Lana
Hey Lana,
You can just waterproof the bench and niche if you wanna. Nothing wrong with that as long as you do have the moisture barrier behind your wall. If you use kerdi make sure it runs from the corner of your bench to about 3″ or so up the walls and about the same outside of your niche. Do the same with the Redgard if you go that route. If you simply stop it at the corners you may still leave space for water to sneak through. You want some overlap there.
Good luck! And send pics or I’ll send guedo to get ’em from you!
Thanks so much for your help! Much appreciated!
You are very welcome, Lana.