I get a LOT of questions about how to build and waterproof a bench in your shower. I’ll touch on the easiest method here, but there are a couple of different methods you can use.
I will describe simple framing of a bench with your substrate over it. You can also use after-market, pre-fabricated benches. Better Benches (google it) attach directly to your wall substrate, the top gets filled with deck mud and it gets tile. There are also several different Styrofoam products available from companies like Schluter and Laticrete. They are made from the same type of foam used for their shower bases. Although they are ‘foam’, once tiled they are more than sturdy enough to support your tile.
While you ‘can’ build a bench in your shower after you form the shower floor with deck mud, it’s always easier to make your bench first. Your floor substrate is flat, your shower floor (should be) sloped. It’s difficult to build a level bench on a sloped floor.
But you can do it if you wanna.
As I said typed, the easiest way is to simply frame a bench and cover it with your substrate. The waterproofing is ALWAYS easier if you use a topical membrane. Either a liquid like Hydroban or redgard, a sheet membrane such as kerdi, or a topical board like kerdi-board.
If you are using traditional waterproofing in your shower with a membrane behind your substrate, I will cover that in a little bit.
The rules for benches and concrete are the same as curbs and concrete. If you are building on top of concrete rather than wood use bricks (cinder blocks) to build your bench. Just stack them up to the height you need and bond them to one another with regular thinset.
There is no hard and fast rule to framing your bench. Just build a square frame box out of 2×4’s and put your substrate (cement board, or drywall if you’re using kerdi) around it. It’s really that easy. If you want to build a corner bench then build a triangular frame, or arced frame, to place in the corner.
The first couple of photos are small bench frames I made for showers. The top one is only 2 ½ feet wide by 1 foot deep. It is 22” high. I normally build them 21 or 22 inches high, but that isn’t required either. The other two are corner benches.
Be sure you slope the top of your bench ¼” per foot toward the front of the bench! Water needs to drain off of it rather than collecting in the back of it.
So how do you decide how high to build it? Ask the woman in the house. I’ll let you guys in on a little secret. The bench she wants you to build in the shower? She’s not going to sit on it. She wants it so she can shave her legs. Really. Ask her.
So it really depends on how tall she is and where the comfortable height is for her. Ask her. Starting to see a theme here?
It usually looks better if you build the bench around the size of your tile. For instance, if you have 12” tiles, don’t build your bench 25” high because you’ll have a 1” strip at the bottom. It’s not imperative to get it exactly the size you need it, but keep the tile size in mind while building it.
Your bench doesn’t need to be huge. It can even be just a little triangle in the corner, like the one above. It’s for a foot, not a butt.
Once you get it framed and covered with your substrate just waterproof it with your choice of topical membrane. This one is kerdi.
And this one is kerdi-board.
I don’t have any photos of a cinder block bench, but it’s just as easy to build one. Stack your cinder blocks up however high you want them, minus 2”, with the open holes vertically. Once you get them stacked up place cinder block ‘caps’ on top. The caps are solid 8 x 16 x 2 inch bricks that fit right over the top of the cinder blocks to give you a solid top.
Once again, make sure the top of your bench, in this case the caps, are sloped ¼” per foot toward the front of the bench.
Once the thinset cures just cover your cinder block bench with your topical waterproofing.
Now, if you are using a traditional waterproofing method it’s a bit different. You need to build your bench BEFORE you put your membrane up on the walls. I really don’t recommend this method, it’s a pain and if one thing is done incorrectly then your bench may leak. But it can be done.
And I don’t have pictures of that either, because I don’t build them like that anymore. But I will answer any questions you may have about them if you leave a comment below.
Frame your bench against your wall framing and put a solid piece of backerboard on the top, making sure it’s sloped. When you run your membrane down the walls, run it down and over the bench, down to the floor overlapping the front of the floor membrane.
Your regular substrate will be installed on the face of the bench (and the sides, should you have them) but you need to make the top of them 1” higher than the frame. The front of your bench is treated as any of the walls. The floor membrane runs up it and the wall membrane overlaps that with the substrate screwed to the front.
Your substrate will stick up 1” over the top of the frame to form a ‘box’ around the top of your bench. Your seat, the top of the bench, is formed from deck mud. The extra 1” will give you an edge for your top and the top is simply shaved flush with the top of the substrate. Tile is bonded directly to the cured deck mud on top of your bench.
You cannot use your wall substrate on top of your bench! It will drive fasteners through the membrane on a horizontal surface – it will create a problem. You need to use deck mud.
If you are going over concrete and using the traditional method you need to build and waterproof your entire shower, then build your bench INSIDE the shower, so the waterproofing is surrounding your bench. There is no waterproofing on the bench itself, it’s all under and around the bench.
If you build your bench inside the shower it needs to be built out of cinder blocks. You cannot frame a bench inside your shower using wood unless you are using a fully topical waterproofing method in your shower.
This is why it’s better, and easier, to use a topical membrane of some sort for your bench. It is, in my opinion, the only way to build a bench. If you want a bench, spend the money for some sort of topical membrane for it.
If you have a bench you cannot use a topical membrane only on the bench with traditional membrane on the walls. There is no way to channel the water from your membrane behind your wall substrate, over the membrane on the bench, then into the floor membrane (unless your bench is built inside your waterproofed shower).
As I said typed, there are many ways to build a bench for your shower. This is the easiest. I realize some of this may be confusing due to different types of waterproofing and lack of pictures. I only build my benches with topical waterproofing, so I just don’t have them.
The important keys are to ensure that your waterproofing on the wall is continuous from the wall, over the top of the bench, and down the face of it, and to ensure that the top of the bench is sloped toward the drain. Anything wooden needs to have waterproofing OVER it, and the waterproofing needs to tie into both the floor and the wall membranes.
I’m absolutely positive there will be questions, so leave a comment in the comment section below and I’ll answer it as best I can. Not necessarily about this method, either, if you have a question about any of the pre-formed benches, better benches, etc., I’ve used most of them and can answer those as well.
Below are a bunch of photos of different benches. Look through them first, you may discover an answer in there. You can click on any of them for a larger version.
I’m grateful for the information you shared.
This blog deserves recognition.
I built a wood bench using 2x10s, including a (sloped) 2×10 across the top. I put a CPE pan liner on top of my pre-sloped deck mud, and ran it up and over the bench and 6 inches up the wall all around. I’ll do another 1.5″ of deck mud on top of the liner. Based on your guide, I plan to attach durock to the front of the bench (as well as all walls), and go 1″ above the bench and fill the top with 1″ of deck mud. Then I plan to Redguard the durock. Questions:
1. If I Redguard the durock that is attached to the front of the bench, wouldn’t that give me a waterproof sandwich no-no? What should I do?
2. Do I need wall substrate on top of the bench, rather than (or on top of?) the wood 2×10?
3. Or, should I just cut off that CPE liner from the bench and do durock+redguard over the bench?
Thank you so much, you are such a great resource!
Hi Lisa,
Your best option is to do the mud on the top, durarock on the front, and run redgard over the face of the front and top, as well as a couple inches up the wall.
In normal circumstances yes, that would give you a sandwich. However, with the bench you have all the open area beneath it to help dry it out (it isn’t necessarily a closed system as a 3 1/2″ wall cavity would be) and any water that does end up behind it is only coming from the wall behind the tile. The major percentage of water will be prevented from entering there because of the redgard.
Hello my name is Clarence and I am building my shower. My plan is to put down felt paper then a layer of concrete to get my pitch to the drain and next rubber membrane and concrete bench then hardy board and then my concrete floor
Hi Clarence,
You need to use deck mud for your shower floor, not concrete. Read through these posts and it will give you a good basis to start: How to Create a Shower Floor – Part 1
Roger,
Your site and book has been a huge help for me in understanding the whole process. I’ve done well because of your willingness to share your knowledge and that’s a big deal these days.
I do have a situation that I haven’t yet found a solution for on your site or in the book. I am using a complete Schluter Kerdi 48”x48” shower kit. I have the floor piece to put in but I also planned on having a bench. I don’t know how to build the bench on the floor piece that comes with the kit. I guess I can spend the money later and buy one of those fold down teakwood benches that just mount to the wall. But I have all the materials I need to frame up a bench in just minutes. Have you ever used the floor that comes with the kit and have you built a bench on it? If you can help me once more I would really appreciate it and you more than I do already.
Thank you!
Robert
Hi Robert,
You don’t build the bench over the Schluter pan, you build the bench and run the pan from the wall to the front of the bench.
You can either get a 48×36 pan (assuming your bench is 12″), or cut the existing down to fit.
IF you cut the pan you need to cut an equal amount off of opposite ends to maintain the perimeter. You cannot cut 6″ off of one end, you need to cut 3″ off of each end.
And yes, it will screw up your drain placement. The floating bench may be your best bet.
Thank you Roger. I had a feeling I wasn’t supposed to go over top the floor pan but given everything I’ve read I didn’t have a good answer for myself. Thanks for getting back to me so quickly! I’d buy you an adult beverage of your choice if I could but I’m in the northeastern part of the country, in PA. and if I remember you are in Colorado. If you ever come to Philadelphia I would love to thank you and maybe show you around the city.
Thanks again!
Sorry I posted this question at the bottom in response to a different question by accident. How would you attach your shower pan liner to a concrete block bench? My thought is to still go up about 6 inches and then connect it somehow…..just not sure whats the best way?
Great sites! Thank you for doing these
Hi Ryan,
If you use concrete blocks to build your bench, the bench gets built over the liner. You install the entire liner as you would in a shower without a bench, then build the bench over it.
I have built a shower curb with three stacked, dry-kiln, 2×4’s.
Is it sufficient to use Kerdi-membrane per the curb?
Hi Bruce,
No, you want a substrate of some sort, like backerboard, over the 2×4’s. You don’t want to install Kerdi directly to bare wood, you need some sort of barrier between them. Bare 2×4’s expand and contract and the kerdi membrane does not compensate for that.
I already have kerdi membrane over my wall. I have built my shower bench out of wood and was going to cover the wood frame with kerdi board and kerdi waterproofing strip in between seems of board. I was going to secure bench to concrete floor and wall via Keri Fix . I then plan to pour the shower base and then seal around bench and floor with kerdi membrane. Do you see any problems with any of the steps listed above? Your website instructs to attach bench to wall BEFORE adding membrane.
Hi Nicole,
If you are fastening it to the wall with kerdi-fix rather than mechanical fasteners (screws), there is no problem with your plan.
Floating bench?
I am framing a steam shower on concrete basement floor. I was going to frame, go board and tile two ledges about three inches wides on either side of a four foot span and build a teak bench top to rest on them. I know I would have to maintain or replace the bench top periodically. Would this work? Could I use 2” goboard or Kerri to build the ledges? Could I do this with a 2” slab of Go Board or Kerri for a floating tiled bench top?
Hi Christopher,
You can do it with 2″ Kerdi. You may be able to do it with the go board, but I don’t have experience with that so I can not give you a definitive answer there.
I love your comment about women wanting a bench to put their foot to shave their legs. That is exactly why I’m reading this post! My shower doesn’t have one and it’s so annoying I’m going to retile the tub and shower area JUST to add a foot bench. So you are spot on with that statement! Thanks for the great post! It was very helpful!
I highly recommend the floating benches. The one I did was Innovis brand. Remember to slope slightly to drain. Before troweling on waterproofing, I did the corner pieces with pre formed orange, Kerdi? Mine I put between two reinforced walls. Corbel used for a corner shampoo shelf.
How would you attach your liner to a concrete bench? Great sites by the way! I’ve been referencing them throughout my bathroom remodel!
Hi Ryan,
If you use concrete blocks to build your bench, the bench gets built over the liner. You install the entire liner as you would in a shower without a bench, then build the bench over it.