This post covers:
- Cement board, foam board, and Hardibacker
- Cutting into wall framing
- Waterproofing
- LOTS of photos!
First, if you haven’t read my post on 10 things to consider before building this shampoo shower niche, please do so before moving forward.
The Ultimate Guide to Building a Preformed Custom Recessed Shower Niche
Other niche building posts:
Part 4: Building a Custom Shower Niche from Scratch
Sometimes there’s no good way around it.
Building your own custom recessed shower niche from scratch can be the best way to add much-needed storage in your shower.
Not every shower works out perfectly to be able to put in a standard-sized preformed niche. Sometimes it makes more sense to start from scratch rather than make modifications to standard-sized foam niches.
So let’s start at the beginning. What material do you want to create your custom shower niche with?
Building material
Foam Boards
Most of the time when I build a custom shower niche I end up using Wedi board. I save my scraps so I always have some on hand. The nice thing about Wedi board and Kerdi board are that they come in different thicknesses.
This can be an advantage when trying to get a niche to layout with the tile. I may end up going with a 1/4 inch thick board on one side and a 1/2 inch on the others.
Another advantage to foam board is that they are easy to cut to size and doesn’t create any airborne dust. Also, the board itself is waterproof so once it’s installed and the glue is dry it’s ready to tile.
It does need to be installed like the instructions. With lots of glue. Schluter requires additional banding over the seams and penetrations for their Kerdi Board products.
Cement Boards
Niches can also be made out of cement boards like Durock and Hardibacker. These products are not waterproof so they will need an additional waterproofing membrane over them.
Kerdi vs Redgard
To waterproof over the cement board, I recommend either a sheet membrane or a liquid waterproofing membrane.
Liquid waterproofing is much easier to use for this than trying to hassle with all the cuts and folds of a sheet waterproofing membrane.
Examples of sheet membranes are Kerdi, Durock, and Valueseal. Examples of liquid waterproofers are Redgard, Hydroban, and Aquadefense. More on these below.
Building your custom shower niche
Much like the other niches types of niches, you’ll need to have these steps done:
- Tile backer board installed (at least most of it)
- Tile layout and niche placement figured out
- Niche location framed in with blocking on all four sides
Cutting studs in the shower
Sometimes there’s a temptation to cut the wall studs in a shower wall to accommodate a custom shower niche. After all, it is custom, right? Before you do this here are some things to keep in mind:
I don’t recommend cutting any studs on an exterior wall. Same thing for a load-bearing interior wall.
Load-bearing walls are interior walls that are holding up your house. Not all interior walls are holding up your house. In fact, most of them are just there to divide the space up.
Oftentimes, when you see an interior wall that is 2×6 construction it’s a bearing wall. With non-load-bearing interior walls sometimes you can cut a section of a stud out and have it be no big deal.
If you decide that you know what you are doing and want to modify the framing of an exterior and/or bearing wall for a recessed shower niche then the niche should be framed in like a window would be framed in.
Additionally, it probably is proper to get a permit when doing this. This is a tile blog though. I’m not going to give out advice on framing other than this:
If you don’t know what you are doing then don’t cut any studs!
Hire a professional for that aspect of it.
Cutting the wallboard to fit the niche
Assuming the backer board is already installed on the wall around the niche then this is how I typically go about it.
Cut a piece of backer board to install in the back of the niche. This can be either 1/2 inch like the wallboard or you can go thinner with 1/4 inch thick board for example.
The advantage of a thinner board on the back wall is that it gives you a little bit deeper of a shelf.
Then cut some pieces for the top, bottom, and sides. So, if you are using the 3ft wide backer board you might cut a strip at 3 3/8″ by 3 ft long.
Then cut the top and side pieces to length out of that.
Installing the wallboard
- You’ll need to mix up a small amount of thinset and put some thinset on the back of the backer board for the niche.
- Use a 1/4 x 1/4 inch square notch trowel for this. Comb the thinset all so that the ridges are all going in the same direction.
- Install the backer board on the back wall and wiggle it so the notches on the thinset collapse. Don’t screw or nail this piece in! Usually, you would be sticking it to the back of a sheetrock wall.
If you are installing this on a deeper wall, such as an exterior wall, then you’ll need to frame in some blocking to attach the back piece.
Assuming that’s the case, then you can forego sticking the back piece on with thinset and screw it into the framing blocks. For an exterior wall that you are installing this niche in you may want to read my post on this.
Side and top pieces of the niche
Upon installing the back piece, the side and top pieces can be installed.
No thinset is necessary under these pieces. Just screw them in.
If you’re using Wedi board or Kerdi board then I usually just put screws and washers down the middle of the strip.
If it’s cement board then I will screw a row of two screws in: one screw towards the front and one in the back.
Note for Wedi board users: You’ll want to make sure to put some sealant on all leading edges of the board before screwing it in. Just like if you were installing walls.
If you miss a spot then don’t take any chances. Pull the board back out and use more glue.
Slope the bottom
The bottom of the niche needs to slope slightly so that water will run out. But not so much that nothing can sit on the shelf.
The rule is 1/4 inch per foot minimum so I usually slope the bottom of the niche 1/8 inch.
One way of doing this is to plane the bottom 2×4 that you install for the niche. This means removing 1/8 inch of material from the front of the 2×4. Obviously, this would be done prior to installing it.
If you don’t want to plane the board then here’s an alternative way of doing it:
- The bottom piece of backer board on the niche should be thinset and screwed down no matter what.
- Typically I will apply thinset to the bottom 2×4 in the niche with my 1/4 inch square notch trowel.
- Then I put some tile wedges or spacers along the back. Maybe every 3 inches or so. Right in the thinset.
- Notch thinset on the back of the backer board.
- Install the backer board in the thinset and wiggle it. The back should wiggle down until it touches the wedges. Wiggle down the front and be sure it slopes.
- Screw in the bottom backer board
Sealing the seams
If you are installing foam board in the niche then you’ll want to apply more sealant to all of the seams and smooth it out.
This is where the plastic Wedi corner tool comes in handy [link at bottom of page]. Do the entire inside and outside around the niche.
If you’ve installed a cement board then you’ll want to thinset and tape all the seams.
Alkaline-resistant 4-inch mesh tape is nice for this. You’ll want it in every inside and outside corner. Fill in all the gaps with thinset.
Note for Kerdi membrane users: When installing a waterproof sheet membrane in the niche you can forego the mesh tape step. The membrane will act as the tape for the seams.
Waterproofing your custom shower niche
Wedi board users: You’re already done! Your seams should be waterproof and you’re in business!
Sheet membrane users: Precut the sheet membrane for the niche. Make sure to overlap all seams by 2 inches minimum. I would apply a dab of sealant(Kerdi fix, Nobleseal 150, etc) in the corners for good measure.
Liquid waterproofing people: Scrape down any high spots in the thinset that has dried from the last step.
Apply a thick coat of liquid waterproofing over the entire niche. A paintbrush is usually the best tool for this job. Pay special attention to the bottom shelf of the niche. Make sure the membrane soaks into any pinholes.
Once this layer is completely dry (including all the corners) you can apply a second coat.
Thickness: A common mistake made with liquid waterproofing is people put it on too thin. However, it can be too thick also.
A general rule of thumb is to apply it “driver’s license thick.”
If you want a more exact way of determining the thickness then a wet film gauge is best [link below]. The exact thickness of each liquid is different and can be found in the installation instructions.
Once it’s waterproofed you’re ready to tile. For more on this step see
How to Build a Recessed Shampoo Shelf
Finally, if you’d rather forego the custom niche you could always add some elegant shower corner shelves.
Products and Tools mentioned in this post:
This post contains affiliate links. The site owner may earn a commission should you click on an affiliate link and make a purchase. Read more
Tools
- Torpedo level with slope indications
- Dewalt 20v impact driver
- Horseshoe spacers
- Wet Film Gauge
- Wedi Corner Putty Knife
Supplies
Waterproof foam backer boards
Liquid Waterproofers
Waterproof sheet membranes
Hi Jim,
Thanks for this fantastic tutorial — the pictures are especially helpful! I have built a custom niche, but in my excitement to get everything put together, I forget to thinset the bottom piece of Durock to the supporting 2×4. Can I just be extra diligent in my waterproofing (thinset and mesh tape, followed by a generous coat of Redgard)? Or is this a huge mistake that I need to take apart? I ran the bottom piece of Durock underneath the side pieces, so I would have to dismantle most of my work.
Thanks in advance for your guidance!
I’d say it depends on how you sloped the bottom. If the 2×4 underneath is pitched forward then you’d probably be ok. If you pitched it like I’ve shown, with plastic spacers, then I think the mortar would be a good idea because it would take out any voids that would be underneath the bottom piece.
Thanks for your quick response, Jim. I didn’t use spacers between the 2×4 and the Durock, so there is no gap. I plan to use spacers to get the bottom piece of the tile at the correct pitch. Does that sound like a reasonable plan?
What you want is the slope to be at the waterproofing level so that any water that gets down to the sill- underneath the tile- will still have an escape route to the drain. So, unfortunately, this would mean going backwards a little bit before going forwards.
Do you have recommendations on waterproofing the area around a vinyl window in a tub surround? Seems like a similar situation to the niche but with a joint to the window frame at the back instead of a wall. Current plan is to install backer board sides, top and bottom (sloped), leave ~0.25″ gap between board and window, waterproof with liquid membrane, caulk between backer and window frame, and cover with thinset+tile.
Is this correct? Is there a better way to set up the joint around the window? I’m worried that if the outside caulking has to be replaced, the backer-to-window seal will also get broken when the old stuff is getting removed. Backer rod between the 2 layers? Thanks in advance, I would appreciate any advice.
Yes, it’s similar. Use whatever waterproofing that you are using- in your case it sounds like a liquid. Then backer rod and caulk the gap between backerboard and the vinyl window frame. The caulk can be either silicone or urethane.
The steps that you’ve outlined sound exactly right.
Hi there
First of all, what a great website! I really like your way of explaining how things are done and your pictures. I’m soon going to be tiling my new bathroom and will visiting here a fair bit during the process!
Anyway, just a question about shower niches. I have two relatively large ones built in (600mm x 300mm) and was wondering if there’s a particular sequence to tiling a shower with niches? For example, do you do the walls and then the niches? Niches first and then walls? Or simply tile them as they come up as you do the wall tiling?
Also, I’ll put in a glass shelf in each – would you put the shelf holders into the grout line and grout them in?
Pretty simple questions I guess, but useful to know the techniques the pros use for this sort of thing.
Thanks
Simon
I do the walls first, then the sill, and let that dry so I can stack tile off of it later. Then I install tile in the niche. Usually top, back, then sides. There are a lot of ways of doing things but that’s how I usually do them.
The glass shelf you can put in a grout joint if you like where that lays out. Typically, I caulk them in but grout would probably work as well. You might test it first and see if the grout scratches. Usually, it won’t.
Thanks for the comments!
Jim,
Any guidance on cutting clean miters in porcelain tile for corners? I saw a picture of a beautiful gray tile niche that you tiled with mitered corners and it was outstanding.
I’ll be renting a wet saw for my installation but wanted to collect tips from pros like yourself first. Thanks!
There’s a few ways to do it but probably the easiest way if you are renting a wet saw is to get a saw that miters. This means the head will tilt.
But you’ll be dependent on whatever the rental store has so if it doesn’t tilt then you can make a wedge out of wood, or something, so the tile itself will be at a 45 degree angle.
They do make special wedge products for this purpose but they are saw specific.
If you have a lot of bevels to cut them I would use an old blade or buy a cheaper one to use for this purpose. The reason being is that you’ll wear out one side of the blade faster than the other and the blade won’t cut straight after a while.
Good advice — thank you.
I’m throwing around the possibility of using Schluter edge trim also, although I think it will be more noticeable than I’d like. For that reason, I’m leaning towards the bevel approach.
FYI, Schluter does have some options besides just aluminum and chrome. There are some colorful choices that may be appealing if you don’t want the metal look.
Good morning. I’ve never seen backer board placed directly to drywall. Is it safe to assume that this done quite a bit?
I am about to remodel our bathroom and will be making my own niche. We’re actually turning the tub area into a walk-in shower.
Any suggestions on prefab shower floors. I’ve been thinking about using the Schluter Kerdi kit.
Typically, 1/2 inch backer board is installed in place of drywall and not in to of it. I’m not sure if that’s what you are referring to, or not.
I haven’t used all the different prefab shower trays. In fact, the only one I have much experience with is the Wedi system and it’s one that I would recommend.
But the Kerdi system is good, also Hydroban and the USG Durock system have all had good reviews. With Kerdi, you have to attach the membrane to the pan but they have probably the best videos and instructions.
So I don’t have an individual product recommendation but the ones that I’ve mentioned above have good track records and are good choices.
Have you ever used corian as the bottom shelf in a niche? Would you attach it with thinset or silicone? Would you put it over cement board and membrane or just attach it to the supporting blocking directly?
I haven’t used Corian before but have used products like quartz. I’ve installed them with mortar and siliconed around them.
Always attach after the board is installed and after the waterproofing is done.
Why not achieve the slope of the bottom of the niche by ripping the wood blocking piece at a slight angle? Or do you just not have the tools for that with you on site?
Nothing wrong with it at all! In fact, it may be a better way of accomplishing the same thing. I typically have a skill saw available and that’s about it. Plus, I’m a tile guy and shouldn’t be allowed to handle carpenter’s tools. ;-)
Jim, thanks for all the helpful information! With regard to where the window ledge meets the window frame, should the gap be caulked with silicone before or after application of Redgard or Laticrete?
Yes, it’s a good idea to caulk that area around the window. I recommend doing it after waterproofing as the liquid waterproofers will not want to adhere to the silicone. You’ll have to keep the gap clean though.
if you put cement backer board around a shower wall do you have to water proof with the liquid on the entire shower before thin set and tile ?
You need to manage the water in some way and there is more than one option. I recommend taking a look at these two posts which I think will answer your question. Please let me know if I can be of further assistance.
https://www.diytileguy.com/durock-cement-board-waterproof/
https://www.diytileguy.com/shower-waterproofing/
Do you do anything with shallow niches? The best wall for a shower niche is 2×3 construction. I’m going to shim it out some but it still leaves only about 2-1/4″ which would hold a shampoo bottle but would look funny and doesn’t seem worth it. I could extend a ledge but that would also look funny and seems a bit dangerous. Wife doesn’t like the idea of corner shelves. Might need to just hang up some narrow glass shelves on metal hangers attached through the tile. Are there some options I might be missing? Otherwise we might be shamefully hanging a caddy on the shower head.
You could put a piece of quartz or granite on the bottom of the niche and have the piece extend past the niche just a bit. I’ll see if I can find a photo as an example tomorrow.
For non-niche options, you could always install some shower shelves.
Thanks, those do look good. That might be the winner. But $200 for a shampoo basket? Damn.
If I want to mount something like a grab bar by drilling and putting screws through the tile, is there a good way to waterproof the attachment points if I’m using redgard over cement board? The Tileware bar mounting system looks good but I wanted to keep the wallboard in one piece where the bar would go.
The thing to do is usually just to fill the hole full of silicone before you mount. That’s what shower door guys do.
Thanks so much for your site, it’s very informative and I have already learned so much. I’m hoping you can help me to plan for a project that I’m researching. My shower has an old aluminum crank-style window in the back wall, which I plan on removing and thought it would be a perfect spot to build a niche. I have a couple of issues I’m trying to figure out .
First, this window is set in what used to be an exterior wall. I added a utility/mud room on the other side so now the window opens into another room. As far as the wall construction goes, it doesn’t really matter in this house. The entire house is built with cinder block walls covered with a thick layer of concrete-like material that I think is mortar. Interior and exterior walls are all built the same way, with the walls being about 10 inches thick.
The window is 17-3/4″ wide x 36-1/2″ tall and 44″ from the floor. The “frame” is concrete, 18″x37-1/2″ The top and bottom ledges slant horizontally, with more of a slant on the top than on the bottom. The top slants up and is 4″ wide, the bottom slants down and is 3-3/4″ wide. The vertical sides are straight, 3-3/4″ from the window. The opposite side is built the same way, with about the same measurements.
I’m trying to figure out how to frame this in (after I figure out how to remove the window!). As I understand it, I don’t need to do any backer board for the rest of the shower, the concrete is basically my scratch coat. But obviously, I will need to build the blocking – attach it somehow to the concrete – and then create the niche with some sort of backer board. I’m leaning toward your suggestion of using Wedi board.
Would you recommend I fill in the hole in the wall with concrete block and then attach wood framing to make the niche (finishing with Wedi board as you suggest)? What sealant and glue would I use? Can you think of a better way to do this, or would you recommend that I scrap the niche idea altogether and just fill the hole and tile?
Secondary question, not really niche-related, but one of the walls in the shower is bulging. I’ve had new plumbing installed, so the cause is fixed, but to level out the wall it was recommended that I could save some money by using pieces of cement board to fill in any deep areas, then build out the wall to a smooth finish with mortar. Would you recommend this as well?
I really appreciate any help or tips you can give me in dealing with this problem. I’m forced to diy this one myself, and although I’m fairly handy and have completed a lot of different home reno projects myself, I have only tiled with LVT. I’m fairly confident in my abilities to pull it off, but the condition of the walls and concrete are making me really nervous. The previous owners had apparently just glued the tiles to the concrete, and once the shower started getting regular use, the tiles literally just fell off the walls. I need to be sure that doesn’t happen again.
If you have the money for a foam board I think that is the solution to all of the problems.
Structural foam is changing our industry and they are even using it for freeway offramps and that sort of thing.
I don’t like the idea of you tiling over the concrete directly. You should have walls that are waterproof and this waterproofing should tie into the shower floor which should tie into a drain.
A normal basement floor drain isn’t going to work either. You’ll need either a bonding flange drain (Kerdi drain) or a 3 piece shower drain.
But to answer the questions: the niche can be framed in with foam panels. Use Wedi or Schluter or whichever but use the sealant that goes with their product.
You can cut up their panels and construct the opening to your liking.
You can also use the foam panels to go over the wall with a hump in it. By using the glue you can flatten the wall out.
Wedi and Schluter put on local classes all of the time. I would encourage you to look into their systems and see what you think of them.
There’s also Hydroban board, GoBoard, Probably board, and Durock foam panels. They are all competitive of each other and perform essentially the same function.
It’s a little more money for the materials but it’s a much easier DIY then trying to incorporate wood framing into a concrete structure.
Just curious, does your bathroom have a ventilation fan or is that window the only available ventilation? Because if it’s the only way for moisture to exit the bathroom, you might think twice about removing the window.
Thank you so much for taking the time to give your speedy reply! You are a godsend – watching your videos and reading all the information here has given me courage with this project. Please keep up the great work; your tutorials and explanations are the best. So many diy blogs that you find either skip over relevant information, or answer questions with a canned answer that doesn’t really answer the question.
The structural foam board does sound like exactly what I need. I found some Wedi kits on HD, and I see what you mean – they are pretty pricey, but it sounds like they will save me money because I don’t have a lot of time to mess around with the other options. They have a 1/4″ underlayment kit that includes five 2x4x1/4″ panels and a tube of their sealant (plus some screws and washers that I wouldn’t need). I was told that 1/4″ cement board is appropriate for floors only, for walls you use 1/2″. Is it ok to use 1/4″ of the foam for the walls, too?
Of course, the same guy at Home Depot that told me I could just tile directly on the cement is the same guy who told me about the thicknesses of the cement board, so I’m not sure I believe anything he said at this point.
Also, thank you very much for taking the time to go over the drain, too. I obviously have some more research to do, but any tips or hints like that are very welcome. The shower currently has a regular shower drain installed, but the floor is not sloped correctly. I don’t suppose I could attach the foam board to the floor and use the sealant to even out the slope, could I? This house was built in the 1940’s and as I mentioned in the earlier post, every wall – interior and exterior – is cinder block with a concrete coating.
I had to pay a good deal of money to get the faucet and shower head replaced, mainly because the plumber had to cut and chisel the pipes out of concrete and metal mesh in order to replace them. He was able to raise the shower head from around 5.5′ to around 6′ tall, which is still too low lol. The floor drain isn’t centered, either – and I do not want to uncover any additional problems under that floor, which is why I’m re-tiling instead of trying to fit a tub and surround into this teeny space. So I’m hoping I can unscrew the current drain head and replace with one of the options you recommended.
Hi Colleen, good catch. Yes, it’s the only ventilation at the moment, but I am having a pro install a light/fan combo in the ceiling. Part of the problem with the shower was lack of ventilation in the first place. Let’s be honest – I like getting away with not installing any other ventilation, but no one opens a window in the shower in the middle of winter in Michigan :)
The bathroom had mold and mildew everywhere. I had a mold remediation and cleanup company do the whole house last month. Trying to make sure that never happens here again. Thanks for the comment, it’s a great point.
I’m not sure about 1/4 inch foam board over walls. If the 1/4 inch board is completely supported underneath (behind) then I think it would be fine. But if you did blobs of glue every so often then I think 1/4 inch board would have too much flex and 1/2 inch would be better. 1/2 inch is designed to span 16-inch center spacing (14.5 inches unsupported).
For the shower drain I think you would have a couple of different options. The first three involve foam shower trays.
1. Schluter makes an adapter for a standard 3-piece shower drain which you have. It’s not the cheapest but it would allow you to incorporate one of their foam shower trays.
2. A company called KBRS makes foam shower trays also and I’m pretty sure that they are designed to fit with a 3-piece shower drain. That might be an option.
3. You could cut out your current shower drain and put add a 2-inch drain pipe to extend up above the concrete. This would allow you to use a Wedi shower tray. This may not involve cutting out concrete as you only need to reach just below the current drain.
With foam shower trays, I understand there is additional cost and if you don’t have a centered drain then you will have to cut the trays and add extensions onto them which adds further to the cost.
Another option would be to get a custom-made foam shower pan. There are several companies that make these. I think the companies mentioned above will all make custom foam trays.
Finally, you can do a mud pan shower pan where you mix a sand topping mix and make your own shower base. I think the best way to do these with foam panels is to use what’s called a drain flashing. Here’s a link to the one Noble Company makes and I’ve used several times.
noblecompany .com/products/nobleflex/
You would install foam panels on the walls, install a “mud” shower pan with a “divot” drain. Then put a waterproof membrane on the top of it with the drain flashing. Wedi makes a membrane called Subliner dry. I’ve also used Noble ValueSeal and Kerdi fabric works just fine also.
I know this is a lot of info. Here’s a link to a thread that goes over the “divot method”. This talks about doing it with a liquid waterproofing but it can easily be done with a sheet membrane with a drain flashing described already.
https://www.johnbridge.com/vbulletin/showthread.php?t=72403&highlight=divot
This might be too much info but let me know what path you are inclined to take and we can go further from there.
I am so very grateful for your help, you just don’t know! No way to thank you enough. I still need to read through the links so I understand exactly what you’re saying. I read through the divot thread, but really need to go over it again to understand the process. KBRS looks awesome, but really pricey. If this were my home, I might be more inclined to spring for it. Ugh – balancing price vs labor is hard! lol
Again, thank you so much for your help. I will ping back when I’ve done my due diligence on this.
I understand. I have a couple of photos on my Instagram page of a divot in use but don’t know if that’s helpful, of not.
All the high tech products are expensive but they are problem solvers.
Is it okay to leave the underside of a shower shaving shelf made of a waterproofing wedge exposed? The top and sides are tiled and grouted.
Assuming the bottom side is waterproofed it made of something that won’t deteriorate, such as aluminum, then yes, it’s ok to not tile it.
If it’s wood then answer would be “no” it shouldn’t be left like that.
Hi John,
I’ve got my niche built, sloped and waterproofed. I now realize that for the wall tiles to be nicely spaced around the niche I need to add another thin piece of hardiebacker to the top of the niche. Should I treat that piece of backer board like a tile and thinset it in, then install my tiles over that once it’s dry? I’m thinking I wouldn’t want to screw the additional piece in and make holes in my nice waterproofing.
Thanks,
Liz
I’d rather see you screw it in, tape the seams with mesh tape and thinset, and waterproof over it.
I have ALWAYS used continuous Corian pieces for any place remotely horizontal (my brother was a lic Corian person :-) so lots of scraps ), “if” a whole tile will not fill. Cubby bases, Shower thesholds, Seats (kitchen sink cutouts).
NICE SITE! Nice to see someone who knows what they are doing. Tile was my specialty of the crew. Martha’s Vineyard trophy houses, & custom work for almost 40 years.. So I was usually able to frame the shower wall for my cubbies to line up to the tile grout lines like your photos do. So I always did custom cubbies. Plus I always added extra studs for hanging shower doors. Some ended up with 1/2″ glass doors! I was able to use Corian for the bases, & shelf, if there was one. Which some times I just angled the 2 side pieces of tile a tiny bit out, so a tight shelf would sit on the top bit of edge.
Extra framing for shower glass is important!
Thanks for your comments input. :-)
You refered to exterior wall to install a niche.
At least in most northern state and Canada, this is against the building code.
Aaargh! We planned our niche and our tile layout, only to discover that what the tile company lists as a 12 x 24 tile is actually an 11 3/4 x 23 9/16. Now my husband has to cut out the niche and rebuild and rewaterproof it…..unless you have any other ideas. We just can’t get the grout lines to work out so that it looks good. Our tile is supposed to go to the ceiling, and we had planned on stacking it…not doing a 1/3 offset. (Our other showers are stacked and we like the look.) The new shower is in place of an old 5′ tub that we removed. Any suggestions, other than get the tile in one’s hands BEFORE doing layouts and building niches?
It’s always advisable to have the tile in hand before beginning as tile always varies from manufacturer to manufacturer, as you’ve found out.
Most 12×24 tiles are really 30x60cm which is about 11 13/16 x 23 5/8. But even then they will still vary. Sometimes, they vary from batch-to-batch.
Hello DIYTileGuy
I know this is an older post, but wow is it ever helpful. Thank you for making it and including pictures. I do have one question though…
For the bottom backer board that used spacers and thinset–I am assuming that if the wood had the right slope no thinset would be needed–you could simply screw the backer board to the bottom shelf.
If I am wrong–please let me know :) I am building one of these right now!
Thank you again!
The rule of thumb that I use is anything that is on a flat horizontal surface will get thinset underneath it. So if you haven’t done it yet then I would mortar underneath. But I would also say that’s it’s unlikely that not doing so would be the cause of problems with such a small elevated space.
Hi TileGuy,
Would this solution work with a steel casement window as well? We’re working with a contractor and his tile pro who have tried to get us to change out to a vinyl window in place of our steel casement (which we’re trying to keep if at all possible).
If so, is there an “elegant” way we could introduce this solution to our contractor?
Thanks!
I’m trying to picture what a steel casement window is? All I can think of is aluminum frame. I can’t imagine that steel would work well in a wet environment but if there’s something that I’m missing please let me know.
I used a shower pan made by Tile Redí, its made of polyurethane which is very light and one of the best features is that the drain is built into the pan. It is sloped 1/4” per foot so you just level it onto a mortar bed and let it set. Once set, it is like concrete. It comes with an epoxy used to set your tiles right on to it. They have many different sizes and shapes. The standard tub sizes are comparable to the price of Kerri.
Good morning – Thanks so much for your post and website, it’s great!
I am making repairs to my master bathroom. The shower has a tile floor and tile wall, the line where the walls and floor meet (the 90 degree angle) was originally grouted (I have pictures if that would be helpful). The grout had begun to crack in parts, so I cut most of it out. The line (which runs the perimeter of the rectangular floor of the shower) gets a fair amount of water exposure, but is seldom submerged under water for a significant period of time, unless the drain is clogged. I was hoping to get a recommendation from a tile/shower installation specialist as to whether it should be re-grouted, caulked or sealed with some sort of silicon sealant (or perhaps there is another alternative I hadn’t thought of). And what product(s) would you recommend (there are a lot out there).
Many thanks,
Patrick
You want to use 100% silicone sealant and probably some backer rod. This post, with a video, answers your question and shows how to install 100% silicone without a big mess.
https://www.diytileguy.com/silicone-caulk/
Thanks for the great info here, I am a tiling rookie to be sure.
One question I have:
Why is it necessary to install the backer board to the drywall in the back of the niche? Is their an added benefit to installing backer board in the back of the niche versus just waterproofing over the existing drywall in the back of the niche? I always thought backer board was used for the tile to adhere to but if you are just waterproofing over the backer board then it would lose that attribute so why use backer board in the back of the niche at all? I am probably missing something here, just curious as I am about to do this myself. Thank you for your time!
Most waterproofing products aren’t approved for going over drywall. So, if you install 1/4 inch cement board over the drywall then you can apply the waterproofing over that.
Thank you for such a terrific post! I’m a little concerned though, as I am reviewing the photos of my last remodel job (done by a professional contractor) and they did not seal the niche with a waterproof membrane. They only used hardibacker board, and I’m not even sure that they did a mesh wrap over the seams. How big of a deal is this? Should I have the shower redone? I live in a condo unit with downstairs neighbors, so a leak could be disastrous.
It’s hard to say what’s going to happen but that is a potential leak spot. So, I guess it depends on how much water you think it’s getting but it would make me uncomfortable, for sure.
I have installed a custom made niche for my shower. My intent was to finish the niche with aluminum schluter edge trim I am using 13×26 wall tiles laid landscape and wanted the grout line to line up with the top and bottom of the niche opening. I did not account for the height of the schluter therefore my niche rough opening is not large enough for the grout line to align. Any ideas how i can recover from this? I was thinking of changing the design to just use the aluminum trim around three sides and use a piece of quartz to finish the bottom side of the niche and have the quartz hang down below the bottom grout line to hide the miss alignment.. thoughts?
What you are proposing might work. It’s hard to know without seeing it but hopefully, you can fix it fairly easily. You could always remove one row of tile around it and rebuild the niche to be the proper size. Mistakes happen sometimes.
do you have options for installing a corner shelf for a waterfall feature I would like to create with local rock.
We are about to apply the liquid waterproofing membrane aquadefense to our shower for waterproofing. I have already used the fiberglass mesh tape in the corners. I am wondering if I need to also use the fiberglass fabric for the liquid waterproofing on top of the mesh tape in the corners. As for our niche, we have not done either the fiberglass mesh tape or the fabric for the liquid waterproofing membrane. I have seen posts where people do one or the other, but not both. Do you recommend using the mesh tape rather than the fabric for the niche?
Mesh tape and thinset is all that you need with Aquadefense. You can use the fabric if you want. There’ really isn’t a downside to doing so.
Hi, another Nick here with about the same question, doing same project! I saw on YouTube video where the guy from Ottawa did the same thing, just applied AquaDefence on the back of the drywall to save a bit of space. I appreciate what you said about not being approved over drywall, but do you suppose I could just apply a thin coat of thinset on the drywall and then AquaDefence? Would be like a thin cement board.
And one more question, if you had a choice between AquaDefence and RedGard, which would you choose? Both are available to me at same price. Seems that there are 2 camps on which is better, but I trust you Mr. DIYTileGuy!
I’d lean toward the Mapei product and I don’t think the thinset will help. But that’s just a guess.
I am installing a shower pan and will be tiling the walls and bench. Actually, plan to place a quartzite slab on the bench, to match the vanity countertop.
It seems to me there is a weak link for waterproofing where the wall meets the pan flange. I have seen one video where the guy fills that gap left by the thickness of the backerboard at the flange and the bottom row of tile with waterproof tape and thinset. The thinset is just to provide a reinforcement to the tile.
I wonder if waterproofing that interface of the cement board to the flange would be to place a bit of fiber mesh tape there and paint with Redgard, like the rest of the cement board? Of course, there will also be caulking there in the 1/8” space to the pan, but that, by itself seems like a weak link in the long term.
The best way to do it is to shim out the walls so they drop down in front of the flange. However, it isn’t always practical to do it that way. So, check out this post where I outline three different ways of handling that junction. https://www.diytileguy.com/tile-tub-flange-gap/
Hey there! Love your site, it’s crazy how hard it is to find accurate info on the web, almost feels like cheating!
We are converting our tub into a his/her shower, there is currently no showerhead. The current vale has a shower hookup, so no issue there, just run a showerhead to the valve. There is a 28″ x 11-1/2″ gap at the opposite end of the tub. The current plan is to build a 2.5″ thick stud wall at the end of the tub for the other valve/showerhead to fit into. And build a “towel shelf” [9″x15″] that faces the bathroom, and “shower shelves” [12″x11.5″ (either tiled or glass shelves?) that face the shower area. See picture at this link if you’re confused: https://imgur.com/a/XV32feK
1) I am assuming I should use 1/2″ cement board for the “stud wall”, I have 1/4″ left over from the floor, so would like to use this if possible, maybe with blocking behind?
2) Can I use 3/4″ plywood & 1/4″ cement board to separate the two shelves, or do I need to use 2×4 or similar for strength? I don’t want the tiles to flex obviously.
3) Can I do a shower shelf (aka niche) that is 11″ deep, as long as it slopes? And I would rather not build out and tile 2-4 shelves for this, can I cut tempered glass to fit (or find some 12″x12″ glass shelves maybe?) What would you recommend?
4) The exterior wall is cinderblock with old plaster currently, I am assuming I need to remove the plaster wall, then can I thinset 1/4″ cement board to this, waterproof with redguard, and then tile onto this? Would obvously prefer goboard or kerdi, but don’t have that in the budget.
Thanks again! You provide an amazing service for us DIYers!
Caleb
Hi Caleb, I’m going to take these as you numbered them.
1. The cement board manufacturer’s don’t recommend 1/4 inch cement board on walls. The one exception being Hardibacker, I believe. It’s probably because of flexing so if you block it then that should fix that. I don’t know how frequently to block it. Maybe 18 inches? You might check with the manufacturer and see what they say.
2. Plywood and cement board should be just fine, I would think, especially if it’s supported 11 inches apart.
3. The 11 inch deep shelf is just fine. The glass, I’m not so sure. Are you thinking 1/2 inch glass? I would check with a glass supplier on what the limits are for their products.
4. This is one where I’ve got to be the bearer of bad news. There isn’t any cement board manufacturers that I’m aware of that approve their product being attached to a concrete block wall.
They want their product fastened and that’s difficult in this situation. However, 1/4 or 1/2 inch foam board would work as they will approve adhering it to a wall. I think Schluter has a video on how to attach their Kerdi board. That’s what I would recommend for that wall.
Great, thanks for the reply!
1) The end walls are the only stud walls, and they are 28″ long, so 16″ OC studs, with blocking vertically every 16-18″ you’re thinking? Could I use two layers of 1/4″, samwhiched with thinset or just screws? Maybe best to just buy 1/2″?
3) I think I found some 1/2 glass shelves that are 12×12″, so my guess is they are rated for general strength, but I will check! Maybe I will build one tiled shelf and do the rest glass, but only 6″ deep or something.
4) I was afraid you would say that. It is an old plaster wall on cinder block, can I put 1/4″ foam board over the plaster, or I need to chip all the plaster off? I’m just confused, if it is a structure issue, can’t I just thinset/tapcon 1/4″ hardibacker over the plaster/cinder block and red guard that? The wall is very stable, obviously. I also am REALLY not excited about chipping away all the old plaster and trying to get the cinderblock somewhat smooth, so if there is a way around that, but I want to do it right if I can!
1. 1/2 inch is the best but 1/4 blocked regularly might be OK. Is 18 inches frequent enough? I don’t know. You’ll have to check it as you go if that’s the way that you decide to go.
2. One thing to check is all of your measurements. For example, your tile is probably about 11 3/4 inches wide but the glass shelf might be a true 12 inches. If so, will it still fit? You won’t be able to cut the glass shelf so you’re kind of stuck with it at whatever width that it comes in.
3. I don’t understand why you would have to chip off the plaster in one scenario and not the other? I would think it would be more important to have a smooth wall if you were fastening the board than if you were simply attaching it. Check out the Schluter video on Youtube to see how they do it with Kerdi board. It’s probably different than you would think.
Also, I would think you’d want to go 1/2 inch foam board for the back wall if that’s the option that you choose.
Ok, great! So I could leave the plaster in? I know you are not supposed to tile over drywall, I thought the same with plaster walls. The plaster wall overhangs the tub flange, so I was a little worried about coming out into the tub too much. Or did I read that wrong, and I would need to remove the plaster in either scenario?
So if I don’t decide to do foam board, which I may if I can budget it, the plan is to screw (or thinset?) the cement board over the plaster/cinder block wall. Waterproof with red guard and mesh tape. Then thinset/tile over that. Does that seem right?
Thanks again for all of your advice on this, so hard to find accurate info on the web!
You probably want to remove the plaster if you can. You could do foam board on the block wall only and cement board on the two end walls. The Redgard would be for the cement board walls only. Then you would want to apply waterproofing tape in the corners
Ok! I tried removing a section of plaster (I’m assuming that’s what it is) from the cinder block wall. it looks like it will be a real pain to remove, but doable if that’s recommended. I’m going to see if I can source some go-board locally, seems to be more in my price range, the back wall is 6×7 ft. I’m assuming 1/4″ go-board would be sufficient, since it’s going on block wall?
And just to clarify, there’s really no option to not use foam board on the block wall? Attaching cement board to the cinder block with tapcon screws and thinset isn’t an option? Just wanted to check, just in case I can’t get go-board locally here in WV, USA.
Thanks!
Caleb
You might have a hard time finding GoBoard in 1/4 inch thickness. The most common is 1/2 inch. As far as the 1/4 inch, I’m not sure if GoBoard would approve of that going on a wall. Maybe if it had full mortar coverage on the back? But I don’t know if that’s practical in your situation. You might check with them to see what they say about that.
I’m not aware of any cement board companies that will bless this installation. However, that doesn’t necessarily mean that it wouldn’t work. Nor does it mean that it would.
This is a question that you would have to ask the tech department of one of the cement board companies because it’s too far outside the norm. They might write up instructions for you on how to do it and then you would have a warranty as well.
Going well – I removed all of the plaster, relatively easy with a hammer drill and chisel attachment! I was able to source go-board, and I spoke with john mansville about attaching. The wall is 1/4″ out of level vertically, I am assuming I can maybe fill this with thinset, or shim? Should I thinset the whole wall planar before attaching go-board, or can I just shim with wood? assuming it is not strong enough to just shim.
Also, for the shower niche, I don’t really want big bulky shelves, can I use 1/2″-3/4″ plywood, with 1/4″ cement board on either side? They would be around 12″ x 12″ and attached on 3 sides.
Thanks again! Glad I was able to find the go-board, it will be worth it to do it right!
This is the concrete wall that is out of level? How did GoBoard tell you to attach their board to it? It seems to me, the Kerdi Board video had spots of mortar on the back. If that jives with GoBoard’s instructions then I think shimming out the board would be fairly straight forward.
For the shelves, can you use left over GoBoard? Or maybe cement board? That would work just fine once they are tiled on 3 sides.
I was planning to use 1/4″ cement board since I still have some leftover from the floor. maybe I am misreading, are you saying that I could just use half inch goboard with thinset and tile on either side as the shelf? or I would need some sort of wood in the middle, three quarter inch or half inch plywood would be fine?
John manville’s people didn’t actually have any experience installing against cinder block wall, but the guy told me just to screw it under the wall, and I was planning on just doing the kerdi board instructional video approach with globs of thinset. but yes, I agree that shimming it out and then blobs on thin set on is probably the best bet. thank you!!!
It depends on how small of a cut that you can make for the front. If you can make a skinny enough piece to fit on the front using backer board then you don’t need the wood in the middle. How are you planning on doing the top and bottom edges of the shelves?
I have some black 12×24 tile left over from the floor, so was planning on three 12×24 niches, finished with schluter roundex trim. Most likely will do the backs with one piece of 12×24, and the sides and front with 6×6 white tile. Good point on the thin cut, I have it framed out with 2×4 now, so the space in between is 3″, worked with my grout lines better, as one niche matches the grout lines, and one niche is centered in between the grout lines.
In the back I would like to save space, my main question is just the strength of 1/2″ goboard with thinset/tile. Can I just use this as the 12×24 back, or do I need some sort of support behind (have just enough space for 1/2″ ply, would love to use 1/4″ luan. it is not going against the wall, there will be shelves behind). Since it is only 12″ tall (less then 16oc) my thought is the goboard is enough?
And I couldn’t find a good answer for calculating final thickness of tile/thinset? I was thinking that 1/4×1/4″ notch trowel leaves 1/8″ thinset, so:
1/2″ goboard + 1/8″ thinset + 5/16″ tile = 15/16″~7/8″ finished tile thickness? But a lot of research says leave 3/4″ for 1/2 backer and 1/4 tile, so does the thinset spread out? I know 3/16″ isn’t a huge deal, just want to get my lines nice and matching! Doing a 1/3 offset on the 6×6 tile (start 2″, 4″to, full, etc) to get my valve and showerhead centered on the tile, took almost a full day just to plan the stupid lines to match everything up!
Thanks again, you rock!
I do like the idea of solid backing on the niche. I don’t think the luan will do a lot of good and I’d be more inclined to go with the 1/2 inch.
However, as long as you don’t exceed 14.5 inches you aren’t required to have a backing as it would be the same as a 16-inch on-center stud bay.
The thickness of the mortar will likely be 1/16 inch or less. Your 1/4 inch notch trowel is held at a 45 degree angle which cuts the mortar height in half. Then when the ridges collapse it’s halved again.
But if you are installing a 12×24 tile, you really should be using a larger trowel or notching both the tile and the substrate.
Right! I used a 1/2′ 1/2″ trowel on the 12×24 on the floor, the bulk of the tile on the walls will be 6″, so I was thinking 1/4″ notch trowel. I called john mansville, and they also said that under 14.5″ is ok, but recommended support if possible. Thanks!