Building a traditionally waterproofed shower for tileI’ve finally gone and done something worthwhile! Well, that’s a matter of opinion, I guess, namely mine. I have written complete manuals on properly building and waterproofing your shower utilizing the different waterproofing methods.

Each manual describes a specific method so you don’t get bogged down with a bunch of information you don’t need for your chosen project. Not sure which method you want? Not sure which methods are available? Didn’t know there were different methods? Start with the free manual here: Shower Waterproofing Manual. That will help you decide which one you want to use based on time, skill and cost.

Once you figure that out you can get the manual that is specific to your particular project. Although these are all mostly completed it’s a whole process to get them ready for you guys. It’s difficult to describe but it includes half a watermelon, platypus eyelashes and a full moon – weird, right? Let’s just say I’ve been writing the damn things for close to two years – it’s not a short process.

Anyway, I do have two of them all finished up, uploaded and ready for you to devour!

I have the complete shower manual utilizing the traditional waterproofing method for walls and floors. This will walk you through the entire process for complete shower floor and wall building and waterproofing. If you are going to have a tiled shower floor and walls and need to construct the entire thing – this is the one you need. You can get it here: Complete traditional shower waterproofing method (Price goes up next week!)

And I have the manual using the traditional method for just your shower walls. If you already have a tub or pre-formed base (like acrylic or Swanstone) this is the one you need. You can get it here: Traditional waterproofing for your shower walls

You can always just click the yellow highlighted ‘Library’ tab at the top to see what’s currently available. If you have any questions just feel free to ask them in any of the comment sections on the site. I always answer them – I’m just super cool like that. 8) I will add the new manuals to the library section as I finish them up.


Comments on this entry are closed.

  • Hogan

    Hi Rodger,
    I plan on purchasing both of your books on waterproofing a shower with kerdi or liquid (since I can’t decide which yet). I’m just wondering if I would be able to use both? Paint on a hydroban and then put Kerdi on top of that. I know it’s over kill but I’ve always thought “doubling up” can’t hurt (ha..ha…i know). But seriously, is there any negative or drawback to using both? Thanks in advance!

    • Roger

      Hi Hogan,

      It can be done with only one major drawback – the weight of your wallet. There’s absolutely no reason to do that, and I honestly can’t say that using both as a full waterproofing option will cause no problems, it’s simply that no one knows. Because there’s absolutely no reason to do it. My suggestion, if you are concerned with doubling up on everything, is to use the liquid. There is a hell of a lot less chance of making an error and you can always put on extra coats – there’s your doubling up.

      While I have (and still do) used a hybrid method in showers, utilizing both products, I only do so with each product for different areas or applications in a shower. For instance, kerdi the entire shower and use liquid for a niche – stuff like that. I would highly discourage the use of both over the entire substrate.

  • Cindi

    I am installing a shower in the basement. I have installed the vapor barrier, put the Durock up and mud and taped the seams and screw holes. Do you mud and tape the bottom seam, between the walls and the floor in a shower? I left the 1/8″ gap as suggested to me, but do I just leave that open, it doesn’t seem watertight to me?


    • Roger

      Hi Cindi,

      As long as your vapor barrier overlaps the shower floor liner then it’s as watertight as you want it. You don’t want to seal that as you may prevent water from draining into your floor liner. Water does not run UP a wall. :D

  • chris

    Here is another question that most tile people disagree on.

    1–Can you apply redgard on Hardi backer? People claim it peels off.

    • Roger

      Hi Chris,

      I have a HUGE list of questions tile people disagree on. People also claim all sorts of things. If you install redgard correctly it will not peel off. No tile people I know disagree on that – ever.

      • Tony

        I’ve had it peel off before. Wipe down the board with a damp sponge to get all the concrete dust off and let it dry, then thin out some redguard with water to make a primer coat before applying full strength. Sticks pretty well.

  • chris

    I have several question, may be dumb but what the hell.

    1–In a 3 x54 shower how many weep holes would you put in?

    2–if you seal the bottom of the hardi backer with silicone and redgard will the water still drain out of the hardi if i gets moisture to it?

    3–In the corners of the hardi backer, you stated in a previous thread you would silicone only. Is that what I read correct? Putting the mesh tape and thinset is not required?

    4– Can the hardi backer go over the flange of the shower, even if one would notch out the backer so it would set flat to the wall?

    • Roger

      Hey Chris,

      1. Two, one toward each outside corner of each end wall.

      2. No. But sealed properly no moisture will get to it. Vapor can dissipate into the wall cavity.

      3. There are two different ways to do it. Tape and mud are the proper way. I used to do the silicone, I’m (slowly) moving toward taping and mudding. Either will work in my experience. Given the choice – tape and mud.

      4. Yes.

  • Jerry South San Francisco

    Need help trouble shooting Hydroban.

    I just finished flood test with Hydroban. I noticed about a dozen small blisters down near the drain ( some on the mud deck and some on the plastic). I broke one and water came out. I let my mud deck cure for more than a week and then slurry coated with 253 to reduce sand. That cured for 3 days. I troweled the first hydroban coat on day one and the second cost the following day. I waited 2 days for flood test. Should I go ahead and break all those blisters and give a third coat? I wish I would have tried Ditra by now. Too late?

    We now have a 4 week old daughter that arrived during the middle of all this bath problem. But I had to get rid of all that mold and I don’t want it back.


    • Roger

      Hey Jerry,

      I’ve seen it do that in a couple of mine. After a day they dry out and it looks completely normal. It doesn’t compromise the waterproofing. I know, it freaks me out too, but it’s fine. I had three different people on the phone the first time it happened.

      Apparently if the top layer cures unevenly it can leave tiny feather edges in spots. When flooded these feather edges let in just a tiny bit of water, which leads to the bubbles you describe. Again, they don’t compromise the waterproofing and they don’t happen unless there is water soaking on top with downward pressure (essentially flooding the base). The continued pressure forces the water beneath these feathered edges, but it’s just a very, very thin layer of the hydroban that has water beneath it, you still have the full thickness beneath those bubbles waterproofing your shower.

      And yes, it still freaks me out when it happens. Almost as much as the hydroban getting lighter when I flood test it. :D

      • Jerry South San Francisco

        Thanks Roger, I guess the flood test was successful because the water level did not move down. It did freak me out to see those bubbles :eek: So you did not apply a third coat when it happened to you?


        • Roger

          No I didn’t. It’s fine, it’s just one of those weird things some of these products do. They all have idiosyncrasies, some of them stranger than others. :D

  • David


    First, I must say your site is fantastic as well as all the advice you have. It is pretty incredible how much help you are willing to give people. Keep that up. Your site was by far the most informative place I stumbled upon when doing research on how to build my own shower. I definitely couldn’t have done it without all your tutorials.

    I recently tore apart my entire bathroom and am in the process of rebuilding it. The shower was the first problem that I addressed. I followed your instructions to the best of my ability, and though I know I wasn’t perfect I felt that I did a decent job.

    I framed in new walls, put in the concrete slope, installed the liner, installed the second layer of concrete, put up the concrete board, taped and mudded the joints, slathered on a hefty layer of RedGuard, and then finished with thin set, tile and grout and then sealed it.

    All was great. For a while, anyway… One of the shower walls happens to be a wall that is shared with my kitchen. I have yet to address the kitchen side of things and still have the ability to see the back of the concrete board. A few weeks after completion and use I noticed that down near the bottom, in between the rubber liner that went up about 8″ and the concrete panel, there was a small portion that was damp.

    I kept my eye on it and it got larger. I am assuming that means that a fairly significant amount of water is getting through the tile / grout and into the upper layer of the concrete pan (which i know is going to happen to a certain degree) and is making its way to the bottom of the concrete board and slowly getting larger.

    Should I be concerned about this? I was away from the house for four days and the spot didn’t seem to decrease in size. I’m just worried about mold. The spot is just damp. By no means is it wet to the touch, but it is definitely discolored due to the dampness and I don’t want to set myself up for a world of hurt later on down the road. I’m no expert and would certainly be the first to admit it, but I’m not sure exactly who to turn to at this point. Any suggestions?

    Any advice is greatly appreciated.

    • Roger

      Hey David,

      That’s moisture wicking up your backerboard. While it shouldn’t cause significant issues, it’s always best to eliminate as much of that as possible. Your top mud deck will get saturated – that’s normal. The moisture should flush through with each shower so you don’t have the same moisture sitting there constantly. Some moisture will wick up your backerboards if you have the backer embedded into the top mud deck and did not seal the bottom of it. Again, this is normal.

      It will reach a point where the amount of water pressure pushing on the backer from the mud bed will equalize with the amount of pressure pushing down from the backerboard. Equalization will stop the wicking and it will no longer spread. The only thing that will prevent this from happening is having clogged weep holes. As long as your weep holes are open the water in the top mud deck WILL drain, it just takes a long time if you are attempting to completely dry it out.

      It shouldn’t cause any problems at all. If you do want to prevent this altogether the amount of work needed depends on your backer. If you have it sitting above the top mud deck you can simply silicone between it and the bottom of the backerboard. If you have it embedded into the top mud deck you’ll need to either cut it out to right above the deck from the backside and silicone the bottom, or dig the perimeter of the mud deck out in order to accomplish the same below the surface of the mud deck.

      I would just keep an eye on it. If it gets any higher than 18″ or so I would guess that the weep holes are clogged. If it doesn’t (and it probably won’t) then it’s just fine.

      • David

        Thank you for the insanely quick response. All of that is good to hear. I made sure to take great care in keeping the weep holes clear when dealing with that portion of things, so hopefully that isn’t the issue.

        I did take a much closer look with better lighting and there is a very small section right where that ‘leak’ is appearing on the other side of the wall where the grout appears to be missing. Probably only about 1/8″ or so, but I’m guessing that has something to do with it as well. This weekend I will throw a small amount of grout together to patch up that spot as well as a couple other small ones I noticed in less problematic areas.

        It is definitely a long way off from 18″, and thankfully I won’t be getting to working on the kitchen for quite some time and can leave that wall unfinished to keep an eye on it.

        I can’t thank you enough for the assistance. I couldn’t have done what I did without it.

  • Terry

    Roger, bought your traditional shower book, but am wondering if the gap between the shower base and the tile will build up mold or growth. i have the 4 mil plastic attached to tile base with silicone but noticed that the gap will be 1/4 from base to bottom tile and am concerned about mold and mildew build up. should this be a concern. if their is a build up how do you clean it.



    • Roger

      Hi Terry,

      There is no worry about mold provided you leave weep holes in the bead of silicone. Water will regularly flush through and drain without worry.

  • Tyler

    A little bit of perfection in a world of chaos calms my nerves – actually I was trying to build my side walls to follow my preformed shower pan as I thought it would look better but perhaps i will now have to think about what you have said (typed) – the marbles are rolling.

  • Tyler

    Hi Roger,

    I measured my walls today and it looks like the worst one is 1/2″ away from being square. Can you tell me what is thinnest amount of thinset I can apply in the corner that you would be comfortable and confident that it will not fall off after I take a shower? I will be putting up 12 x 24 and 12 x 12 tiles. On the far end, it will 1/2″ further away from the wall so I would like to keep the inside at a minimum.

    I was also wondering if you have any recommendations concerning troweling tools for doing what I need to do with the 12 x 24 and 12 x 12 tiles (didn’t realize there are so many d*# options)?

    • Roger

      The thinnest you can install thinset (by standards) is 3/32″. With tiles that size I’ll normally use a 5/16 x 5/16 trowel. Let me ask you this: Why do you feel your walls need to be square? I know that sounds like a strange question, but if the side walls are not absolutely square with the back wall it isn’t going to be noticeable at all and it won’t affect anything.

  • Tyler

    Hi Roger,

    Let me start by saying that your website REALLY ROCKS! After reading, reading, reading..your website I decided to get my feet wet using the described traditional method – I figure I should start at the basics before I get to the fancy fancy stuff so I bought your ebook on the traditional way and marched along.

    Everything went fairly smoothly – your ebook is well written. I plumbed the walls as described and dryfitted the hardibacker. The world was PERFECT. However, after I screwed in the hardibacker and checked for squareness around the corners again I noticed that they were now off by a few degrees and my world was “not” perfect anymore.

    I was wondering if you have any other hidden secrets I can use to make my world perfect again without tearing up my prior work?

    OTHER QUESTIONS (since I have your attention – hopefully):

    1) When the hardibacker transitions to the regular drywall, can you explain what the recommended procedure is? I was thinking of treating the hardibacker like normal drywall using yellow drywall mesh tape and joint compound, let it dry then add thinset on top where the tile goes. I am not sure if this is the correct procedure or even if I am using the correct materials so any comments would be of great help.

    2) For the floor I am thinking of using thinset, 1/4″ hardibacker, thinset, tile in this order. This would be on top of existing 3/4″ plywood. Would you recommend adding ditra or redguard to mitigate any movements in the underlayment? I also have a cement slab in another bathroom I will be tiling which to the uneducated appears solid – would you recommend ditra or redguard on this as well?

    • Roger

      Hey Tyler,

      A few degrees on a 2 1/2 foot shower side wall normally translates into less than 3/8″. That amount can easily be compensated for with a bit of additional thinset beneath your tile to square things up.

      1. Yes, I can explain it – in fact I already have. :D Here: Drywall to backerboard transitions

      2. I always recommend ditra. It’s just a very good, very solid substrate option which eliminates a lot of common problems. For the plywood you technically should have an additional 1/2 plywood layer over that one as well. There are two types of concrete – cracked concrete and concrete that hasn’t cracked yet. I would use ditra there as well.

  • BWR

    Roger, your information has been a great resource as I tumble down the rabbit hole in an attempt to rebuild my shower. I bought your ebook on traditional enclosures, and have a quick question: My shower is going to be long and narrow, about 60 inches from the back wall, where the head will be, to the end of the curb. I’m interested in a curb that doesn’t have a lip on the inside. My drain is towards the back, about 40 inches from the curb. I figure it’s so far away, and there will be so much slope, that a lip on the curb really isn’t necessary. Is this a bad idea? If it’s okay to do, what do you recommend in terms of the lathe over the brick, (since it would be flush with the top layer of mud). If none of this makes any sense, maybe one of your elves can help. Cheers.

    • Roger

      Hi BWR,

      You have the required space between the entrance and the drain to eliminate the lip but you’ll need to use some sort of topical waterproofing at least at the entrance of the shower so water will run back down into the shower and onto the top mud deck. You can not have a liner with a mud deck over it and no barrier at the end of the mud deck, water won’t be channeled, it’ll just run where gravity takes it. Half of that will be inside the shower, to the liner, and into the drain and the other half will be out onto your bathroom floor and into your framing, because it has no waterproofing over it. :D A topical membrane over that curb and onto your bathroom floor solves that.

  • Tom

    1) I have taped and mudded my Hardibacker above my shower/tub and want some advise on what products to seal the the bottom of the Hardibacker and the porcelain tub flange in relation to applying Redguard to the face of the Hardibacker– Do you Redguard before sealing between the flange and backer board (allowing the Redguard to wrap the edge of the Hardibacker) — or would you apply silicone (Type?) and then run the Redguard down to and over the sealant?

    2) I noticed a rubberized gasket thingy at the Building Center that is used to help seal around the faucet/shower pipes that gets set into the waterproofing– is this a good idea, bad, or indifferent? Set into Redguard or thinset?

    3) I inherited a window in the tub and have replaced it with new Vinyl Sash Unit which I intend to frame a return with Stone, tile, or Corian with Silicone seals at the face of the windows frame and where the returns meet the tile surfaces. Initially I was going to tile the returns- but feel better about a siliconed solid surface returning to window to minimize horizontal leaks… thoughts?

    • Roger

      Hi Tom,

      1. I prefer using a silicone bead (silicone is silicone – no matter what the marketing guys say…) then running the redgard down over it. It won’t stick well, but it will seal any spots the silicone missed. It leaves a tight seal.

      2. Is it the ditra gasket? Any rubber gasket with waterproofing fabric attached is a good idea. It gets embedded into the waterproofing.

      3. Seal the transition from the return to the sash with silicone and paint the redgard over it like at the tub flange. Solid surface normally looks better, but properly waterproofed it makes absolutely no difference.

      • Tom


        Thanks for your insights and honest humor throughout your site!

        A couple more items as I move from waterproofing (completed) to tiling…

        1) I am removing a old sheet vinyl floor that was layer over 2 layers of 3/4″ plywood and tucked under the tub. I am keeping the enameled steel tub and will be laying a tile floor adjacent to the existing tub.– What is a typical/recommended way of finishing a mosaic tile floor that bumps against the tub–assuming some sort of silicone sealant.

        2) I am considering a stainless steel cove trim (i.e. Schluter-DILEX-EHK) for the transition from standard glazed wall tile to the mosaic floor. Any thoughts about this product? vs. a) a radius-ed ceramic cove base tile (silicone at bottom joint?) b) standard wall tile overlapping floor mosaic (with silicone seal?) c) sanitary base tile similar to b) with top bullnose trimmed off?

        3) Any comments/recommendations for or against unglazed ceramic mosaics vs glazed mosaics in terms of installation or long-term cleaning/upkeep?

        4) Is there a “standard” treatment of sealing the “chrome” trim of the spouts and controls at the tile penetrations and at the actual trim– i.e. a bead of silicone with weep hole at bottom…?

        5) I have a small part of the subfloor that had dry rot in the upper 3/4″ ply–can I just fill this with thinset as I lay the 1/4″ Hardibacker?

        6) Any experience with electrical heating grids laid under Hardibacker? Doesn’t this create an uneven foundation for the flooring unless it is buried in thinset?

        Thanks again for sharing your experience/wisdom!

        • Roger

          1. Leave 1/16″ to 1/8″ gap between the tile and tub and silicone that joint.

          2. I like the dilex, good stuff. I also like regular bullnose. I hate the coved tile and regular non-finished tiles look, well, unfinished.

          3. Glazed is always going to be easier to clean as well as more durable. Unglazed tiles are very porous and prone to staining, by everything – including the grout you use.

          4. Just a bead of silicone, no weep hole. Although a weep hole won’t hurt anything, no water should be getting behind there to drain.

          5. As long as the dry-rot is cut out. (I know that sounds basic, but when I don’t say it…)

          6. If you are using hardi for your underlayment the heating element is installed between the hardi and tile, not under the hardi.

  • Luke

    You may have already touched on this somewhere else, but couldn’t find anything related to framing in a seat/bench. Is it possible to use the traditional waterproofing method with a framed-in seat? It seems like water would find it’s way through the holes created by the backerboard screws on the horizontal part of the seat.

    I’ve seen other online methods to waterproof the full cavity then add the seat to the waterproofed cavity, but I’m adding this seat to cover a pump basin on the opposite side of the wall, while adding space in the shower.


    • Roger

      Hey Luke,

      Yes, you can use the traditional method. Make sure your frame is properly sloped then place a ‘dot’ of silicone on the board where you’re going to screw into it and drive the screw right through the middle of it. That will seal the penetration.

  • Gabriel

    First, thanks so much for this website. My girlfriend still has no idea I’ve never done this before. She thinks I’m an old hat.

    We purchased a drop in hot tub (off craigslist) and are fitting it where the old tub was installed. The tub is designed to drop into a surface and so it doesn’t have a lip to catch water running down a wall. Where the tub butts up against the wall I’d like to know how to properly waterproof it. Right now we have 4 mil poly sheeting on the walls and will put up backerboard. Can I stuff backer rod behind the tub, run a bead of silicone on the tub and lay the poly over that? I assume I would then trim the poly once the back lard is in place. My concern about this plan is that dried silicone doesn’t seem to even pretend to stick to the poly (I siliconed the poly to the studs and it is so easy to pull off).

    BTW, the old bathroom was 50 year old drywall with plastic tiles glued to the wall. That is a special mold breeding ground.

    • Roger

      Hey Gabriel,

      If you’re filling a space with backer (which you should do) you should install it like you mention, but use a construction adhesive rather than silicone. I prefer sika-flex (you can find it in the concrete section). It’s waterproof and will stick to the poly. It’s similar to kerdi-fix and works very well for situations like yours.

      • Gabriel

        Thanks for the lead. I got the Sika flex and glued the poly down to the tub.
        The poly is glued to about 1″ from the studs. I figure that the backerboard and tile will get me 3/4″ off the studs. Any suggestions on what to do with that last 1/4″ of poly sticking out? Use lots of thinset and tilt the tiles? (surely that can’t be the thing to do)

        • Roger

          No need to tilt the tiles at all. Your tile is at least 1/4″ thick, no? They should cover it just fine. If not, install your tile then after it’s cured run your razor knife along the tile at the bottom and cut off the excess.

  • Rob


    Thanks for the site – good information.

    I am building out 3 showers in a renovation project. I think I am going with the Hydroban pre-sloped pan and Hydroban over Cement Backer Board on the walls.

    Which of your books best matches up with this approach?

    Have you used the Hydroban pan? Looks like a new product and I can’t find much feedback from folks that have used it? However I am kind of sold on the fact that if I use all Laticrete products I get a lifetime waranty and I can still use modified thinset.

    Following the Laticrete recomendatoins it looks like I will use Laticrete 254 thinset, honed Travertine on the floors and walls, Laticrete perma color grout, Latasil at the drain joint and between the joint between the walls and floors, then sealing Travertine and Grout with Miracle 511 pourus plus sealer (figure I will seal last as I will need to fill any holes in the Travertine with the grout).

    It appears I have the option of using the 9235 fabric at the wall and floor joint if I want – althougth they say I don’t need it…

    Any thoughts on this approach?

    Thanks for your time to respond.

    • Roger

      Hey Rob,

      The liquid topical manual would probably work out best for you. You can find it here: Topical waterproofing for showers.

      I have not used the pan (I rarely use pre-formed pans – size issue) but the guys I’ve spoken to that have find it easy to work with.

      The use of fabric at the changes of plane isn’t really necessary but it does give a good, solid junction. I’ll do it sometimes depending on the size of the shower. Don’t know that I’d use it with the Laticrete pan – not really needed there but it wouldn’t hurt.

  • Sandro

    Hi Roger, I’m pretty sure I read the answer to my question somewhere on your site but I can’t find it now. I installed denshield around my bathroom tub surround. One of the tub surround walls is an exterior wall which had vapour barrier. I left the vapour barrier installed behind the denshield on this wall. Fiberglass mesh tape and mortar filled the joints of the denshield. Wall finished with 12″ x 12″ porcelain tiles. How likely am I going to have to redo this bathroom in the near future due to the denshield disintegrating?

    thanks for your time, much appreciated!


    • Roger

      Hey Sandro,

      The densshield shouldn’t disintegrate at all. The only thing that may become an issue is trapping vapor in the wall cavity between the densshield and barrier. If it’s just a regular tub surround, though, it shouldn’t be an issue unless the shower is used a LOT, like three times daily. Just be conscious of any mold appearing at the plane changes or any strange consistent odors which would indicate mold behind your substrate.

  • Patti

    Hi Roger,

    i’m spending $2,500 on a new shower install. Our shower curb is made of concrete/mortar. Does the shower pan liner still need to to go over the curb? The builder did not bring it all the way over and said it’s only necessary if you use wood or other material for shower curb. From what it appears, it goes half way over and then several layers of hydroban was placed on top followed by thinset and tile. Thank you

    • Roger

      Hey Patti,

      While not the technically correct way to do it, if he has hydroban overlapping it then it’s waterproof. It’ll be fine.

  • Kate

    Instead of ordering a custom tile-ready shower pan from KBRS as we’d originally planned, we’ve hired a guy locally to make us a cement pan similar to what you describe in your book, which I just picked up, thanks. Our guy usually uses a membrane sheet for his tile-ready pans though, so I’m hoping that it is possible to use a combination of Redguard on the walls and ceiling and he can still do the base/pan per his usual method? So far he’s installed the curbs, drain and put the bottom layer of cement down, angled to the weep holes in the drain. I guess that’s called a deck? It just went in today and is curing.

    I can’t quite visualize what he will be doing next with the wire mesh sheet and how that will end up interfacing with the hardibacker on the walls. I had assumed that I’d need to put furring strips on the studs so that the backerboard would overlap the vertical edges of the shower pan and its membrane, with perhaps a bead of silicone along the bottom edge of where the backer board forms a corner with the shower pan, but I may be confusing things by thinking too much of the backer board installation instructions from the KBRS pan, which would have made weep holes unnecessary in a drain unnecessary.

    Assuming there away to use a combination of waterproof membrane types in a single installation *fingers crossed* I have a few other questions

    1) We’ll need to use a bead or so of silicone on changes of plane in the 1/16-1/8 gap between the hardibacker boards, and we’ll need to put down a bead or two again once the tile and grout have been applied and cured to each plane. Right?

    2) If so, for the silicone application at the corner gaps of the hardibacker, should I run my finger down all of the corners in order to provide the best, most even substrate for my redguard and fabric mesh application on the corners?

    Thanks as always.

    • Roger

      Hey Kate,

      1. You will need silicone between the tiles in the corners once they are cured. If he tapes and muds the corners before applying the regard then it isn’t wrong – it’s simply a different method. The corners of the backer can be taped and mudded or siliconed, I simply prefer the silicone method.

      2. Yes.

      He can use the two different methods in the same shower without a problem. As long as the liner runs up behind the backer and the redgard is painted down to the pan it’ll be fine.

  • Glenn

    Awesome resource. Thank you. I’m kind of an “overkill” guy when it comes to my do it yourself projects. Not too concerned about the cost and time as long as its done right.
    Question: I have some roof felt laying around and have decided to use the topical waterproofing method. Couldn’t I use the roof felt on my studs, waterproof substrate (seams and screw heads seald with silicone of course)
    Then apply the roll on waterproofing polymer for a bullet proof,
    water tight, ready for combat shower???

    • Roger

      Hi Glenn,

      No. I like to overbuild things as well but in this case you’re creating a condition which may cause a problem. If you install your topical waterproofing correctly it will be waterproof. Really. Something is either waterproof or not, there aren’t levels of it. As far as being combat ready – a grenade will almost definitely compromise your waterproofing, no mater how it was built. :D Are you in Kosovo?

  • Beth

    Hi Roger,

    We downloaded your Schluter-Kerdi waterproofing with a pre-formed base manual as that sounded like the best way to go… then read on the Schulter-Kerdi site this application may not be good for glass tiles : ( Our situation:

    – An kick-*ss solid surface shower base – very nice!
    – Drywall (that we were going to leave as is and Schluter-Kerdi…)
    – Beautiful 4×12 pacific ocean blue glass subway tiles (about 85 sq. feet total, approx. 240 tiles!)

    Any suggestions on how we can determine the best way to proceed? Do we need to change our approach / switch away from Schluter-Kerdi? Or how can we know if our glass tiles will work with it?

    Thanks for your wisdom and guidance!

    • Roger

      Hi Beth,

      The problem with large format glass (which yours is) with kerdi is the cure of the thinset. Large format glass requires a modified thinset – sometimes highly modified (contact the glass manufacturer to find out what they recommend). Schluter, as you know, recommends unmodified thinset. The two don’t mesh.

      As you may also know – I use modified over kerdi quite a bit. My personal opinion (and that’s all it is) is that I would likely continue with the kerdi – if:
      Your glass tile is not opaque, meaning the color of the tile derives from either a laminated backing on the glass (looks like a sticker) or a paint or colorant on the back of the tile. Look through the side of one of your tiles – if it’s clear all the way through then the color comes from the product on the back of it. And:
      You use a GOOD (read ‘fairly expensive’) modified thinset like Laticrete’s glass tile adhesive, 4XLT, 254 platinum or Mapei’s Ultraflex 3 (Use white thinset with glass – always). And: You let the thinset cure after setting the tile for at least 3-5 days.

      Given all of the above, with proper movement planes (silicone in the corners, etc.) then you should be fine using the kerdi. If even one of them is not an option then you should opt for a different waterproofing.

      • Beth

        Thank you!! The tiles are painted on the back and it looks like we can order the Laticrete 254 Platinum or Laticrete Glass Tile Adhesive off the web without much trouble. Which of those 2 is better? More concerned with excellent outcome than cost : ) Are you anywhere Nashville? We’d be happy to buy you a beer or 2 or 3… Super appreciate your support.

        • Roger

          The glass tile adhesive would be best. The 254 is GREAT stuff, though. Either will work fine. The glass tile adhesive is, uh, made for glass tile. :D

          Not near Nasheville, I’m in Fort Collins, CO. Thanks for the offer, though. :D You can send pictures when you’re done if you want. It’s what I look at while I’m drinking a beer, or 2 or 3…

  • kelly

    I just got your e-mail offering your new Kerdi books. I’m having a hard time deciding whether to purchase though, because you don’t say how many pages are in the book, how many photos, nor do you offer a peek into the book. This is absolutey not meant to be snarky, but your competition provides all of that for his kerdi book, and his is half the price. Kind of difficult to compare. :wink:

    • Roger

      Hi there Kelly!

      Just like my tile installation business I do not let my competition dictate my pricing. I determine the price of my materials based on the amount of information contained within. Also, like my tile business, I often need to explain to people that they comparing two different products. John’s book explains only the kerdi installation method and not the construction of the entire shower itself – mine does. His is meant as a companion product for his hardcopy ‘Tile Your World’ book – a very good book, by the way.

      My manuals are meant as a start to finish information product for single projects – that’s why I have many different books each describing a specific method. I am not trying to compete with John’s books, I’m merely supplying my readers with information and products they’ve requested. :D

      My book is 216 pages – John’s is 81
      My book has 187 pictures (if you don’t count the other 47 graphics for a total of 234) – John’s has 140

      If you are just building a basic shower mine describes everything you need to know. If you have your shower built and want to waterproof it with kerdi or want a curbless (ADA) shower or something like that – John’s goes into more detail about those processes. John’s book is very good, but it isn’t a competition between us – John’s a friend. :D

      I knew as soon as I finished that thing people would begin comparing them. I suppose I need to be more clear on my product pages to explain the purpose of the manuals. Thanks for letting me know! Go get John’s book – it’s very good!

  • David

    I have an old shower in my basement bathroom. I took everything out except the wood framing studs. I can’t afford a custom fitted shower unit. What I would like to do is put up cement board, then use these polystyrene sheets that Lowe’s sells and glue them to the cement board. The floor of the shower is tile with a small cement lip around the edge of the floor. Once I get the walls in how do I seal the walls at the floor? I forgot to mention that I can’t afford a shower pan either. :evilb:

    • Roger

      Hey David,

      Just regular silicone is what you use to seal plastic panels to themselves as well as the shower pan (or in your case the existing tile) to waterproof everything.

  • Mike

    Here is a question to pick your brain. Now in a small cape you don’t have much of a choice where to keep your tub/shower. Now when you spray your stud cavities with closed-cell foam which is a vapor barrier. How do you waterproof your tub/shower with this setup? :bonk:

    • Roger

      Hi Mike,

      You either use a traditional wall waterproofing method with roofing felt directly over the studs and foam and backerboard over the top or you use unfaced batts as your insulation rather than closed-cell foam and use a topical membrane in your shower. Oftentimes your method of shower waterproofing may be dictated by the structural components already in place – like closed-cell foam.

  • Tony (the other one)

    So the guy that originally showed me how to mud a shower floor just mixed quikcrete sandmix slightly damp and build from there. It worked, but always seemed like a lot more of a pain in the a$$ than it should be. Just finished my first shower pan this afternoon using your deck-mud recipe. Wow! I’ve never had a pan come out so perfect before! Great info, well worth the $.

    • Roger

      Hey Tony (the other one),

      Makes a world of difference with the right mixture. It really does. You can’t describe that to people unless they’ve done it.

      Glad to see you’re still around. :D

  • Tony

    I’ve tried to download your free manual several time, but I’m having trouble with the code not matching.

    • Roger

      Hey Tony,

      Sorry about that, I had to use the captcha code now because there’s all sorts of nigerian relatives who apparently want to send me millions of dollars (USD) simply because I own an email and blog – cool right? Spam sucks. Speaking of which – check your email, I sent it to you.

      EDIT: Well Tony, your email host has denied all my emails to you saying ‘invalid recipient’ – are you real? If so please email me at and I’ll reply to that email with one of my own. Apparently either you don’t exist or they think I’m sending you spam – which may be accurate. (You pick)