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.

{ 329 comments… add one }

Leave a Comment

  • Matt

    I built my bench out of wood and am planning on using schluter board, quarter inch thick on top and front to water proof it. Can you use schluter board on the bench top?

    • Roger

      Hi Matt,

      Yes, you can. Howeever, if you are only using 1/4″ I would ensure that you have plenty of support beneath it. It is better to put plywood on the benchtop first, then kerdi-board. But it’s not required provided you have enough support. Kerdi-board has ZERO deflection capability, which means it needs to be fully supported.

  • Marc Addona

    I am going to redo my stand up shower. I have removed all cement board and everything. I want to remove the seat to give more room. Also, the pony wall that is between the stand up shower and the oval garden tub has to be replaced. I am not sure how they secured the pony wall and bench to the CONCRETE foundation. They probably used CONCRETE nails. How do remove that, to remove the bench and reframe the pony wall. Every video shows nailing to a wood subfloor. Thank You

    • Roger

      Hi Marc,

      You can attach a footer for the wall to the concrete with what are called tapcons. Any big box or hardware store will carry them.

  • Joseph

    I built a wood bench and hot mopped it along with the pan. How do I put metal lathe and concrete on the bench in prep for tile if I can not nail or screw it down? Glue or will concrete bond withbthe hot mop.

    Thank you Joe

    • Roger

      Hi Joseph,

      Concrete will not bond to the hot mop. You’ll need to do wet mud on that bench to be able to tile it (no lath).

  • Jeff Brown

    Should I attach the bench to the floor and then silicone instead of grout on the bench to wall joints?

    • Roger

      Hi Jeff,

      Yes. And silicone any other change of plane such as the bench tile to the floor tile as well.

  • Justin Baker

    I believe to the best of my ability I have made a waterproof pan by having pre slope mud, vinyl membrane on bottom and up walls 8 inches, backer board on all walls and ceiling and down to within 1/4 inch of pre slope mud, 2nd mud slope, redgard on all walls and ceiling and about 8 inch in on the floor.

    Now I plan to put a shower bench made with cinder block and thinset and have some questions. When I sit the blocks on they will already have the slope because of mud pan needed but I think that also means the front of the bench or vertical will have a slight slope inward. Will that affect my tile that will wrap around from the walls across the front of the bench or do I need to put thin set on it and try to make it completely vertical?

    • Roger

      Hi Justin,

      Provided you place the blocks against the wall the overall plane will be as level as your wall. However, the horizontal block edges will stick out further than the block above them (due to the slope of the first layer) You can use thinset to even out the edges of the blocks , but it doesn’t necessarily need to be absolutely level unless you want it to be.

      • Justin Baker

        Thanks for the reply. I understand. I am laying blocks in normal position with the holes so you can see them. I will lay two courses to get 16” high. I plan to put a piece of hardi backer on top to cover the holes because I plan to install a solid piece of marble on top. Does that sound ok?

        • Justin Baker

          Well that did not work so well. I now have two courses of block. If you look from top you see the holes of the block. I am putting marble slab on it so I think I need to have a solid surface. I was using type s masonry cement for the block so then I just put that in tip and tried to attach the backer board but it did not work.

          Should I use some type of mastic or will thinset work.

          • Roger

            Thinset will work fine. And with a marble slab it does not need complete support – the holes up method will be fine.

        • Roger

          Yup, that will work fine.

          • Justin Baker

            Thinset worked great. Not sure if this post should go here or not but I have a question about flood test.

            I think you are suppose to do it before the second mid pan but I did not so I have liner and mud in that…ready for tile.

            When I did the test the water level dropped slightly and I think it is because the water is sucking up my walls through the second mud bed. Because the concrete board in the walls went down into that mud. I can see my red guard is darker about 3-4 inches up the wall.

            His is a second floor bathroom and kitchen below. I cant e find any signs if water leaking.

            Do you think my lower level is due to the wicking?

            • Roger

              Hi Justin,

              Yes, it’s due to wicking. The only reason it did wick (I assume you have it painted from the walls out onto the pan a bit) is because a flood test completely saturates the mud and gravity cannot pull it down into the drain. It will not do that in day to day use (in case you were curious).

  • Gregory Cole

    Hi Roger
    I live in SoCal and recently had a bathroom shower floor with Pony wall and Bench all hot mopped. I know I need to use deck mud for floor of shower and top of bench but what type of mud do I use for the front of the Bench with a metal mesh? the Shower floor and bench are both sloped towards drain like require, also the guys left about a ten inch open space between floor and bottom of CBU, once I put in the deck mud do I continue with CBU to top of deck mud? I originally hired a contractor to do all of this but he decided to take the money and run and I am left with a half completed bathroom so I could use any advise your willing to give, Thanks

    • Roger

      Hi Gregory,

      After you get the deck mud in you will want to fill in the remaining wall space with backerboard to the top of the deck mud. As far as the front of the bench (and the curb if you have one) you want to use wet mud. There are a few different options in this post.

      • Gregory Cole

        Thank You, your books and web site are amazing.

  • Jason

    Hi roger. Your website is amazing. Thanks for all your help and advice.

    This is my first shower and tile job I and building a shower with traditional waterproofing just like in the how to videos for goof proof. I framed everything with a corner bench out of 2x4s into my framing. My layers starting from the bottom go OSB, Tarpaper, sakrete sand mix preslope, pvc pan liner 12 inches up my walls and face of bench and up and over my curb using damn corners, plastic over the walls hanging down over my pan liner, then Hardie backer board walls down to about 2 inches or so above the floor. Next laying my sakrete sand mix using my goof proof quick pitch and Kirb-perfect protecting the weep holes and nothing getting screwed or nailed into pan liner within 3 inches of the top of the curb. Using cement board tape and thinset in all the joints. Then my floor will be flat pebble tiled with the wall 12×24” porcelain. Few questions:

    1. Is the sand mix I’m using an ok blend by it’s self. I think it’s 4:1 but not sure. And is that mix ok to use on my curb?
    2. In your post you said to put backer board down under my plastic wall membrane on top of my bench. Is that for the flat structure or do I also need plywood as my bench top then backer then plastic. Do I run my wall plastic continuous down the wall and over and down my bench hanging over my pvc liner?
    3. Next you said to attach the cement board over the plastic on the face of the bench up 1” past framing. So the top of my bench layers will go cement board, plastic, then deck mud with 1/4in slope correct? Can/should I use tarpaper tucked under the wall plastic that goes down over the top of my bench instead of the plastic? In either scenario how do I waterproof the seams in the back of the bench between the seat and the cement board walls?
    4. I have aquadefence that can be used wherever. With my waterproofing method should it be used it everywhere, just the seams and joints, or no where.
    5. Do you have any threads/advice about building a custom shower niche with the waterproof that I’m using. My plan was to cut a hole in the wall plastic around the niche and just cement board everything except the back of the niche is Sheetrock so I would Aqua defense the Sheetrock and everything else inside the niche all over the cement board and maybe a 12” perimeter around the niche. Is there a better method? Thank so much for your help.

    • Roger

      Hi Jason,

      1. If it is indeed 4:1 then yes, it’s fine. I do not know the ratio of that particular mix. For the curb you want ‘wet mud’. That is regular deck mud with powdered lime added to it to make it sticky (essentially).

      2. You need plywood or backer first (doesn’t matter which, you don’t need both), then the plastic down over that, across, down the front hanging over your pvc liner.

      3. Your layers will be plywood (sloped), plastic, then mud (consistent, but it will be sloped congruent with the plywood beneath it). You can use tar paper instead of the plastic. There should be no seams in your waterproofing there. If you don’t run the plastic off the wall over the top, make sure it overlaps the plastic or tar paper you have on the horizontal plane. Ideally you want a single sheet of waterproofing material all the way from the wall to the overhang of your pvc membrane.

      4. I would only use it on the horizontal plane of your bench.

      5. Thinset a piece of cement board to the back of the niche (directly to the drywall), build everything else with framing covered with cement board, then use aquadefense in the entire thing out at least two inches around the perimeter onto the wall. Before you do ANY of that, after you cut out the hole in the plastic for your niche silicone the FACE of the plastic around the perimeter of that hole to the BACK of the cement board on the wall. The idea being that water running down the wall from above the niche will hit that bead of silicone, run around the perimeter of the niche, and continue down the wall without running INTO the niche behind the cement board there. Make sense? (It’s difficult to describe that with just words…)

  • Lee Aimers

    Thanks Roger!!

  • Todd

    Hi great website full of good info! I’m building a bathroom with a shower in my basement on a concrete floor. Here are the steps I plan to follow, please let me know if I’m missing a step or should do something different. Thanks in advance!
    1. Frame shower
    2. Build threshold – treated lumber
    3. Pre-slope
    4. PVC shower liner
    5. Shower pan
    6. Durock backerboard
    7. Waterproof – red guard
    8. Build cinderblock bench
    9. Durock bench and red guard
    10. Tile shower

    • Roger

      Hi Todd,

      Are you using redgard as waterproofing on your shower floor as well? Because if so you do not need the pvc liner.
      Build your threshold out of brick – NEVER treated lumber. Ever.
      It is easier to build your straight onto the concrete floor with cinder blocks before your mud. No need to use durock on the face of it – redgard and tile away.

  • Lee Aimers

    Hello Roger….Great site!!
    When using a quartz top for a shower bench (full width ), should I plan to tile the walls above the bench before putting the top on or put the top down 1st? If I tile the walls first is a silicone bead where the top meets the tile a good enough seal? It will waterproofed underneath with a topical membrane.

    Thanks again for such a great site?


    • Roger

      Hi Lee,

      I put them on before the tile above it. Yes, a silicone bead is fine, but if properly waterproofed it does not ‘seal’ anything (all waterproofing is behind the tile and stone), but it does look a hell of a lot better. :D

  • Angie

    Does a plywood bench that will be tiled in a shower does it have to be treated lumber ??
    Also what kind of tile do you recommend for not slippery floor???
    Please n thanks

    • Angie anain 😔

      Also have ceramic shelves going on we’re they are to be placed has tile there already so how do these shelves get attached to corners ? Please help n thank you

    • Roger

      Hi Angie,

      It does not need to be treated lumber, and shouldn’t be. It does have to be waterproofed, of course.

      Porcelain is normally best, but the slipperiness of it depends on the COF of the tile. This explains that:

  • Ryan

    Roger –
    question about the curved bench in photos 1 through 3 of the slideshow: im working on a shower and I think I’ll end up with a traditional liner (presloped of course). but i want to do a bench with one curved end. Does your manuals cover how one would get the liner in place and then how to get the bench waterproofed? I’d like to do a topically applied membrane or possibly kerdi – but dont understand how those would work with a traditional liner or what the transition is 6″ up where the liner is stapled to the bench structure

    • Roger

      Hi Ryan,

      The liner is not stapled to the bench structure on a curved bench. The liner is built normally, up all the walls, then the bench is built inside the liner. The alternative is to use a topical membrane for your shower floor rather than a liner. Then you can build everything at once and cover it all with the topical waterproofing. A liner is a lot more difficult method to use with a curved bench. With a straight bench the liner is run up the face of it just like any other wall. And no, this is not covered in my manuals. It is, but to a small degree, not detailed.

  • Mary

    In Hawaii, many of the old houses have a tiled shower with a very high curb, say 12-18″ to create a small soaking tub in the bottom of the shower. In the old construction, there was copper under the tiles – I have not seen myself how it was constructed. I’m removing an old bathtub in my condo and considering putting in a combination shower & soaking tub. I have 60″ by 30″ to work with so an alternative to having just a high curb would be to divide the space in half and have one half be a low curb shower and the other half be a high curb soaking tub. How would this be constructed to ensure the soaking tub is fully waterproof? Thanks so much for your informative posts! Aloha, Mary

    • Roger

      Hi Mary,

      Your best bet would be a topical waterproofing membrane. The decks and curbs would need to be formed up correctly to support the amount of water, but waterproofing-wise a topical membrane is likely the only real solution.

      Copper pans used to be used in lieu of the rubber membranes you now see. They are simply a layer of copper – and they are a bitch to remove. :D

  • Darlene Redden

    I am building a custom shower for my husband who has medical issues. I have built a 19″ x 5-foot bench along side of a remanufactured 5-foot shower pan. I’m putting up Hardie board and I have a question or two. When I put the Hardie board on the solid bench top that I have built beside the pre manufactured shower pan, do I set that piece of Hardie board in thinset? And you recommend a liquid waterproofing agent? Because I did not put a membrane over my wood bench frame.

    • Roger

      Hi Darlene,

      The only place you need thinset beneath hardi is on a floor. And yes, you need a liquid membrane over the hardi on the bench. Make sure to take it up the wall a few inches as well as all the way down over the waterproofing on the floor to fully encapsulate the bench.

  • Jardie Lauinger


    I’ve installed shower pans with membranes in the past with great success including lath curb but my new project has a bench in it. I was going to line the wood bench with pvc membrane but then i got confused.

    Some are saying put concrete board over top of the member both the top of the bench and front but won’t i puncture the membrane with the screws and make this useless?

    I’m also seeing some do lath over the membrane similar to the pre slope on the both the front and top.

    Any opinion would be appreciated.


    • Roger

      Hi Jardie,

      I normally build my benches using a topical membrane over a substrate on the bench (without the membrane behind it). If you do choose to do the floor membrane over it then the lath over that with mud on it is the way to go.

      • Jardie

        Thanks Roger

        • Jardie

          Do you think lath and deck mud the top and the concrete board the front and sides and have it go up 1” like mentioned in the article above ? Or do I need to Lath and mud the front as well?

          Seems weird to put concrete board on the front because I’ll puncture the membrane?

          • Roger

            If you use the lath and mud on the top you need to use it on the face as well (because it will puncture the membrane).

  • Brian

    Greetings! We have a shower roughed in that we are finishing, and the bench is pre-built out of wood. Shower floor is still flat, so working on the pre-slope first, then waterproofing. We will make sure bench top is sloped. We ordered a liner long enough to go up and over the bench, but can we not do that? The post on benches is confusing. You recommend a membrane (I assume a goo, not a plastic sheet) on the bench, but then that means we have to use membrane for ALL the waterproofing, yes? Because there is no way to “connect” the liner on the floor to the membrane on the bench, right? And running the liner up the bench makes for crazy probably impossible folds in the corner…? The bench is the whole width of the shower, curb to wall along the short side. Appreciate your advice.
    (From Heather, the Wife writing for Brian as we embark on the project!)

    • Roger

      Hi Heather,

      It is best to use a topical waterproofing membrane over the bench. Treat the front of your bench as the wall, running the floor membrane up behind the substrate. Then paint the membrane over the bench and down to the bottom of the wall substrate. Going over the front of the floor membrane with a membrane covered substrate essentially ‘ties it in’. Gravity makes it work.

      The ‘not tying in’ thing with the two different membranes is using a topical membrane on the floor with a membrane behind your wall substrate. This causes your floor membrane to be in front of your wall membrane, not allowing water from the wall membrane to run INTO the floor membrane.

  • Sofia

    Hi Roger
    I’m building my shower bench out of wood after presloping the shower floor. After that I will cover the floor and bench with oatey liner ( like I will do with the curb). I will follow your instructions using lath on the liner of the curb and use the stucco, then the thinset and the tile. Can I operate the same way with the bench? I thought of snugling the lath over the liner, adding the stuco, thinset and tiles. Is it a good idea?

    • Roger

      Hi Sofia,

      Yes, that will work just fine.


    What a great site with wonderful knowledge. We currently have a tub and want to remove it and put in a shower with a seat and a small half wall on a portion near the toilet and a small curb on the rest. The house is in Florida so it is on a slab, and we will want to use the existing drain location of the tub for our shower. Our idea is to frame up the half wall and the curb and the bench and then cover that and the walls with cement board and pour concrete with a slope toward the drain and use pvc pan liner and a roll on membrane over walls , bench, curb and half wall, is there anything we should be thinking about when we do this? TIA

    • Roger

      Hi Tammy,

      Several things, actually. :D First off, you do not create a shower floor with concrete, you need deck mud. A shower floor with a liner requires two layers of deck mud with the liner between them. The liner runs up the wall, then the wall substrate is installed over it, then you can use your liquid on the walls. Your plan will work fine, you just need to make sure you nail down specifics before beginning.

  • Ann Berg

    Hi Roger, We have your books, and they have been very helpful, but we still screwed up on the shower bench😮 We installed a Schlueter shower tray, but didn’t put the bench in first. We are building a custom shower bench out of Schluter board. So, now, we either have to install the custom bench on top of the foam shower tray, or we have to cut away the shower tray where the bench will be placed. Which would be the best way to fix this screw up?

    • Roger

      Hi Ann,

      I would cut away the shower tray where the bench goes, build the bench, then waterproof the entire thing. As long as the waterproofing is done correctly it’ll work just fine. I wouldn’t try to build a bench in the sloped tray.

  • llbgal

    Hi there. Thanks for your article it has excellent tips. I am installing a new shower in my bathroom and while i knows there are different methods for a shower pan my contractor advised that it would be much less extensive to use a pre-fab pan rather than concrete. I am not site if I’ll explain this properly… but at one end i want to have a bench built… does the bench have to fully sit inside the pre fab pan? I have a corner tub that the shower will run into (i have a photo of the kind of thing i want to end up with attached). So does this have to be custom base or could i use a standard base that is not the exact length but the bench “fills” the extra space?

    Waterproofing done over all of it…

    • Roger

      Hi Iibgal,

      Build the bench, then get a pan that fills the extra space. Install continuous waterproofing over all of it. Pre-fab pans are never less expensive than deck mud. Ever.

  • 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?


    • 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.

      • 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 :)

        • 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.

          • 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?

          • Andrew Hodgson

            You recommend using silicone in the corners of your shower walls when installing backer board instead of packing thinset and imbedded mesh tape? This is to allow them to act individually the silicone acts as a flexible seal between the two boards?
            So does this fact effect the integrity of the walls at the corners.
            And do you first silicone then embed mesh with thinset over the silicone.
            It sucks if it breaks down and looses it bond if there is a traditional lath paper or plastic water proofing behind it does not really matter I guess.
            It may be a issue for a topical membrane
            Applied to backer board.

            • Roger

              Hi Andrew,

              No, it does not affect the integrity of the walls at the corners – provided you also thinset and tape over the silicone. The allowance for movement, for the silicone, is the expansion and contraction of the ‘swelling’ aspect, not necessarily side to side movement due to framing expansion. Think about it like this: if the boards are butted against one another in the corner (or the gap is filled with thinset – same effect) and warmer climate causes the board to expand a bit, there is nowhere for that expansion to go – it will build up pressure. Eventually this pressure will release somewhere – tile is the weakest link. It just allows movement without causing undue stress. It does not necessarily need to remain intact, the silicone is initially placed there to keep thinset out of the gap while it’s being taped and mudded, once that is complete the bond can break down and it won’t make any difference – it has nothing to do with waterproofing – only movement.

  • 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.
    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.

    • 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

  • 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.

    • Roger

      Hi Josh,

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

      • 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!

  • 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?

    • 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.

      • Kevin Hunt

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

  • 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.

    • 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.