limestone shower benchI 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.

Rectangular frame for shower bench

Rectangular frame for shower bench

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.

Triangular frame for shower bench

Triangular frame for shower bench

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.

Arced shower bench

Arced shower bench

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.

 

 

 

 

 

Slope the top of your bench!

Slope the top of your bench!

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.

Kerdi waterproofed bench

Kerdi waterproofed bench

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.

 

 

Kerdi-board waterproofed bench

Kerdi-board waterproofed bench

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.

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Leave a Comment

  • Brandon Lee

    When installing a granite benchtop to the hardi board, what is recommended as the bonding material? thinset? Would you use silicon or other bonding adhesive? What if you need to remove the benchtop at a later date does that factor into the bonding material I should choose?

    Thanks!!

    Reply
    • Roger

      Hi Brandon,

      Thinset. I would not install it with silicone, it leaves too many open areas beneath your granite. NEVER factor in the chance that you ‘may have to remove it’ into any decision when installing tile. That ‘convenience’ may cause undue problems.

      Reply
      • Joey

        To follow up on this same issue. Can you provide additional insight on what you mean by open areas under the granite? Since my bench is sloped, isn’t the theory if water gets under the granite it will eventually drain? Thanks for the question Brandon as I’m about to install my granite bench in the shower :)

        Reply
        • Roger

          Hi Joey,

          Unless the silicone is fully spread then you’ll have open spaces between all the beads of silicone. This allow water to build up under the granite. Water WILL get under it, but if it’s installed with thinset there is no area where any significant amount of water build-up can sit – it will drain immediately.

          Above and beyond that – silicone is NOT an adhesive. It is not permanent, it shrinks and loses it’s elasticity over time, it will eventually compromise any small bond it may have initially had.

          Reply
          • Joey

            Thanks for the explanation Roger.

            Last question (hopefully) about this..

            Is this an area you consider a change of plane and would caulk the edge of bench along tile?

            Reply
  • Joe Kolks

    Hi Roger,

    Great site!
    Now for my question: I am using a Schluter shower pan with the Schluter membrane. I want to build a bench.
    1. The walls have been drywalled in the shower space.
    2. I have not yet installed the membrane on the walls for water proofing.
    3. I am going to build the bench out of 2×4’s and cover with durock.
    4. I am going to slide the Schluter pan in so that it butts up against the bench.
    Questions:
    1. Do I put up the membrane on the walls before framing in the bench?
    2. If the answer to #1 is yes, then do I screw the supports for the bench thru the membrane into a wall stud or do I use thinset to secure the bench to the membrane?

    Thank You in advance for your help.

    Reply
    • Roger

      Hi Joe,

      1. No, build the bench, then cover the walls and it at the same time.
      2. No further comment required – I’m gonna go have a beer. Have a great evening… :D

      Reply
  • Josh

    I am building a new house and decided to do the master shower and bench on my own. I am not finished but am in rough in stage of the house. So, I built the frame for the tub and the shower bench is an extension of the tub deck. I used plywood, then oatey shower membrane that connects into the pan but I extended it up onto the bench. Then I put backer board over top of that, but I did screw the backer board to the seat of the bench and to the wall of the bench. I then used fiber tape and thinset to fill in all of the seams and screw holes. I then used Mapei Aqua Defense over the entire shower and bench. Do you think the screw holes in the bench will give me issues? Next step was to thinset and tile over the Aqua Defense membrane. I put two coats of Aqua Defense. Should I put more Aqua Defense coats over the bench and entire wall to help or should I put a thin coat of deck mud over the tub deck and the shower bench? I didn’t think about putting deck mud until I saw your article here. Thanks so much.

    Reply
    • Roger

      Hi Josh,

      If you have AQ over the whole thing it’ll be just fine as it is.

      Reply
      • Josh

        Thanks very much. Last night, my wife and I actually added a 3rd coat of Aqua Defense to the entire shower and a 4th coat to the bench, curb, and corners. Thanks for your reply. I think it’s going to stay water free for many years… I hope!

        Reply
  • Kevin Hunt

    Do I need plywood under the backer board for my bench? Or will the backer board plus deck mud on top
    be enough support?

    Reply
    • Roger

      Hi Kevin,

      If you are putting deck mud on top you do not need plywood. It won’t hurt, though, and I always prefer more support.

      Reply
      • Kevin Hunt

        Thank you for the response. Your site is a great wealth of information!

        Reply
  • Marye Ann

    My shower floor was improperly tiled and has some places that are uneven. I’d love to add a bench and then just tile over the existing tile floor. I’m a pretty good DIY but I would love some input from you.

    Reply
    • Roger

      Hi MaryeAnn,

      I would remove the tile, build your bench, then retile. Attempting to tile over existing shower floors opens up an entire can of worms, the drain height being just one of them.

      Reply