I get a LOT of questions from my readers about basic shower construction. I understand that my readers don’t consider this stuff basic and there’s no problem with that. The problem is that I end up answering the same questions over and over and over… So, to save what very little is left of my sanity (which is a number roughly equivalent to absolute zero) I will cover some basic things here so I can simply reply ‘read this’.

If you’ve been channeled to this page by one of my smart-ass comments please take no offense to it, I’m here to help. Please understand that I currently have over 12,000 comments (questions) on this site (seriously) which I’ve answered – every one of them. I’m just trying to make your life (mine) easier.  I will continue to answer every question I’m asked, I’m just super cool like that. 8) If, after reading through this, you still have questions feel free to ask them in the comments below.

You can also download my shower waterproofing manual which should answer a lot of questions and cover basic techniques and methods you may be confused about. Go ahead, it’s free.  So without further ado (doesn’t even look like a word, does it?) let’s get on with it. (For all my readers who feel the need to correct me: I KNOW it’s actually ‘adieu’ – I was being facetious. Thanks. :D )

Leaks

First and foremost – tile is not waterproof. Grout is not waterproof. Adding sealer to your tile or stone will not make it waterproof. Your shower should be completely waterproof before a box of tile is even opened! No matter which waterproofing method you choose, proper substrate preparation is the only thing that will make your shower waterproof.

If you have a leak in your shower – stop using it immediately if at all possible. If that is not possible (it’s your only shower) have the shower repaired – immediately. If you see water leaking it is likely not nearly as much water as you don’t see leaking into your wall cavity and structural framing. By the time you ‘see’ most leaks the framing is normally already considerably compromised.

No, there is nothing you can put over your tile to make your shower waterproof if you have a leak – not even sealer. A tile or stone sealer is made to make your tile and grout stain-resistant, not waterproof. It does this by sealing the pores of the tile and stone to slow (NOT STOP) the absorption of liquid and prevent staining. It only means you have more time to clean up the spilled red wine cherry kool-aid before it stains anything.

Substrates

Drywall is not an acceptable substrate for your shower unless you are using Schluter Kerdi waterproofing membrane – that’s it. Cement backerboards are the standard and there are also other products such as waterproofed, gypsum based boards like Denshield and waterproofed, foam-based sheets like wedi or kerdi board.

Cement backerboards are not waterproof. They are water stable, which simply means that they will not swell or disintegrate when exposed to moisture or water – they won’t change size. But they are just like your driveway, they will soak in water, hold water, and dry out, just like your driveway when it rains. If using backerboards there needs to be a waterproof membrane utilized as well.

Membranes

If you are using a topical waterproofing membrane such as a liquid like redgard or hydroban, or a sheet like kerdi, do not use a moisture or vapor barrier behind your substrate. If you have a vapor or moisture barrier behind your substrate do not use a topical membrane on the front of it. This combination creates two waterproof barriers with your substrate sandwiched between them. any vapor or moisture trapped between them has absolutely no way to dissipate. This is lovingly referred to as a ‘mold sandwich’. It is not tasty. Use either a moisture or vapor barrier behind your substrate or a topical membrane on the face of it. One or the other – never both.

With that said, if you want to use a topical liquid such as redgard on the seams of your backerboard, after you tape and mud them, you can do so without problems. If your moisture barrier and backerboards are properly installed there is no real reason to do so – but if it will help you sleep at night go ahead and do it.

If you are using a topical membrane and you have an exterior wall with either plastic facing or kraft paper facing you need to cut slits into that facing before installing your substrate. If you do not it will create the aforementioned mold sandwich. Give moisture or vapor somewhere to dissipate.

Shower-tub transitions

There should be a gap between your tub or acrylic shower base and the bottom of your backerboard. If you are using a traditional barrier waterproofing method you do not need to do anything with this gap. Do not fill it with silicone! This will trap moisture running down your barrier and it will have nowhere to go. If you are using a topical method you can fill it with silicone if you want. If you are using liquid you should fill it with silicone. This creates a waterproof plane between your membrane and the tub or base so water or moisture ends up in the drain rather than in your wall.

When you tile you can tile right over that gap. You should not fill this gap with thinset behind the tile – it will crack due to movement. Your wall and tub or base will expand and contract at different rates – it will crack any cement-based product you place between the two. This includes thinset as well as grout. You do not need a solid backing behind your tile over this gap – it should be less than 1″ wide. You shouldn’t normally be walking on that tile in that particular spot. Yes, it can just hang there.

Grout

If your grout is cracking it is due to movement 99.9% of the time. Type ‘cracking’ into the search box up there and you’ll find in-depth explanations for your viewing pleasure.

If you have white, or lighter than normal grout when you’re finished grouting it may be efflorescence. This is mainly due to minerals in the water being left on the surface of the grout when the water evaporates. It is usually indicative of either incorrectly mixed grout or using too much water while cleaning the grout – not wringing out your sponge enough. This is normally only on the surface of your grout. Scratch the very top layer of your grout in an inconspicuous spot with your fingernail. If you have the correct, or at least a darker, color beneath the surface that is the likely cause. The easiest, quickest fix, provided it is only the very top layer, is to get some drywall sanding sponges and go over the grout lines very lightly. Just like burnt toast – scrape it to the color you like.

Corners and changes-of-plane

Caulk. :D

Disagree with me?

Like any other website I get my fair share of people who disagree with my methods or techniques – it really doesn’t bother me. I am more than willing to have a civilized, intelligent conversation about anything tile related. If, however, you simply attack me personally and act like an uncivilized ass I will call you on it – and not in a nice way. I write this blog in a particular manner, it does not mean that I take my profession lightly – I most certainly do not. If I wanted to be a pompous bastard I currently have 19 letters I can place after my name – all tile related. But I’m not a pompous bastard – you can just call me Roger. :D

If you are a contractor with a customer who has come here for information and I’ve told them you’re wrong – realize that the extent of my knowledge of that particular project is limited to what I’m told by your customer. It does not mean that I am ‘out to get you’ or anything of the sort. I normally limit my replies to those situations by stating the current TCNA and/or ANSI standards pertaining to what I’m told. If you disagree – please let me know in a civil manner, If you’re correct I’ll back it up – I do this everyday, too! If you’re an asshole about it expect the same in return (It’s the comment by ‘Kanela’ with the bold print before it) – and please have a thesaurus handy to interpret my reply – I’m a very well educated asshole.

That’s it for now. I will likely add to this post on a regular basis. If there is anything I’ve caused confusion with please, for the love of God, let me know. I can change this page since, you know, it’s my website and all. If you have any questions at all please ask them below – I’ll answer, really. :D

{ 1494 comments… add one }

Leave a Comment

 
  • Melody

    I am remodeling my bath the room is 12×12′ and I want to have an open shower with only one wall. I want to water proof the entire bathroom from the subfloor. From what I understand you’re saying, I should not waterproof the sub floor before the cement board, but apply waterproofing after cement board. What product would you recommend?

    • Roger

      Hi Melody,

      There are several product you can do that with. My preferred method would be a Schluter bathroom. Ditra as your floor substrate with kerdi-band over the seams to waterproof it, and kerdi in the shower. You can also use redgard or hydroban over all the surfaces (provided you use backerboard) to waterproof everything. Durock also has a sheet membrane which you can waterproof everything. The Schluter or redgard or hydroban are easier and quicker.

  • Lynn

    Roger, your site is awesome. I am tiling a shower with 12×12 porcelain. All prep done. I have read that you prefer to start with the first row from bottom rather than using ledger board. Do you just keep going up row after row or do you wait for first row to set overnight??? I am guessing that if I use spacers to support and level at the bottom, that I should be ok to just keep working up (using spacers everywhere of course). At least that is what I am assuming and I mean “assuming” from some of your answers to other readers.
    Please help!!! I am trying to get this done for my son and daughter inlaw before there wedding in 3 weeks. Thank you. I have learned so much from this site. Your great!!!

    • Roger

      Hi Lynn,

      Yes, as long as you have that bottom row properly supported with spacers/wedges you can continue to stack tile all the way up to the ceiling without problems. Your assumptions are correct. :D

  • Terry

    Hi Roger, great website.
    Unfortunately I found itva day too late! I just poured in my shower pan, and here is my question. I have plastic sheeting behind the durock stapled to the studs as a vapor barrier, but I did not bring the bottom of the pastic over the pan membrane. :(
    How big if an issue is this going to be? I don’t think I can remove the durock since the pan has now been poured into place. What do you advise?

    Additionally I was planning on red guarding the shower as well, but after reading about the mold issue I won’t be doing that… Unless you think the membrane is compromised and I should red guard?? Sheesh what a mistake.

    Thanks,
    Terry

    • Roger

      Hi Terry,

      That is, unfortunately, a huge issue. Any moisture behind your tile will run down the plastic and into your floor/framing. It will not be contained by your waterproofing. Since you have the mud deck against the durock your best bet would be to remove the upper parts of the durock – the ones not locked in by mud, remove the plastic as much as you can from behind the wall, replace the upper wall and redgard the entire wall substrate down to the floor. That would contain all the water in the shower and feed it down into the drain.

      • Terry

        Roger, thanks for the reply. One of my walls is an exterior wall, would I want to do as you suggest and have the insulation open to the back of the durock? Or should I slit the plastic against the insulation and they redgard the front of the durock?

        Thanks again!

        • Roger

          You can just slit the plastic open on that wall. As long as any trapped moisture has a place to dissipate and is not trapped behind your backer it’ll be fine.

  • Beau

    Hello- we are installing a new bathroom in our lower level- there was nothing in this space previous. There is greenboard currently in place where the shower enclosure area is planned to be and has 1 coat of latex primer on it. I have been debating on whether to cut this greenboard out of the area and replace with concrete board and a topical waterproof membrane such as Redgard OR use the Kerdi membrane over the current green sheetrock that is there. I downloaded a couple of your manuals today, but still am confused on whether I can use greenboard as a substrate for the Kerdi membrane. ?? The manual advocates use of either regular drywall or cement board, but in one of the blog replies I thought that I had read that it could be used, of course now I can’t find that… Could you please clarify? Appreciate your help! Beau

    • Roger

      Hey Beau,

      Yes, the greenboard can be used as the substrate behind kerdi. Quit trying to create more work for yourself. :D

      • Beau

        Thank you Roger… Agree, less work! :-D

  • Mike

    Roger,

    A few questions:
    1. I’m installing a traditional waterproofed shower using your new book. I’ve put in my tile floor, 2×2 mosaic tiles. The shower is small, ~32×32. There is a small gap in the back row of tiles between the tiles and the cement board wall which measures 3/4″. I’m trying to decide what to do about this gap–rip a bunch of 1/2″ wide tiles and put them in there? On the walls I plan to use 1/4″ thick 12×12 tiles.

    2. My second question is how to handle the transition between the floor tile and wall tile. I plan to leave a 1/8″ gap and fill it with caulk–Any preference on what type of caulk to use?

    3. I’m assuming the transition between the floor tile and the curb tile should be similar–leave 1/8″ gap and fill it with caulk?

    4. And my last question is how to tile the curb–do you tile the vertical portions of the curb first, and then tile the horizontal area of the curb last? I’m assuming the horizontal tiles overlap the vertical tiles at the corners? What size gap should be left there, and what should it be filled with?

    Thanks for your time,
    Mike

    • Roger

      Hey Mike,

      1. Yup, rip the 3/4″ tiles. With 1/4″ tile on the wall that gap is gonna look like hell if you don’t have tile in there.

      2. I prefer 100% silicone – and a 1/16″ gap. Most grout manufacturers make both sanded caulk and silicone which matches their grout.

      3. Yup, exactly the same.

      4. Yes, vertical first, horizontal overlaps. 1/16″ or so and you can fill outside plane changes (corners) with grout.

  • Javier

    Roger,
    I consider myself a cautious person when tackling a job I’ve done very few times. I was researching the pros and cons of different systems. Most don’t go into the finer detail and that made me look for days and nights without an end in sight. It seems like one system or installer had something negative to say about the other systems or installer. Thanks for making my life (and many other’s lives easier). Also saving us from tons of mistakes and loss of $$.
    The mold sandwich was almost the big mistake I would have made before reading your info and over engineering my job. I love your no nonsense approach and your “I don’t care if you don’t agree with me attitude”. God bless and thanks a million. Javier

    I would definately refer anyone who ask to see your site first before they plan a job.

    • Roger

      Thanks Javier! I appreciate it. If you have any questions at all you know where to find me. :D

  • Deb

    Roger,
    When you are doing a shower with a tiled ceiling, what order do you grout? Top down? and when your on the ladder grouting do you just put cardboard down on the floor to protect the ungrouted floor?
    Thanks,
    Deb

    • Roger

      Hey Deb,

      Yes, top down. You can put cardboard over the floor to protect it if you want. I don’t put anything down, I’m quick enough for it not to be a problem. But anything that’ll cover the floor will work fine.

  • Jay

    Maybe I broke etiquette by posting this under Chris’s earlier post, so I’ll try again (with corrections).

    I left about a 1/4″ gap between the tub deck and Hardi backer board edge, which overlaps the lip. I sealed the botom edge of the backer with clear silicone, but I didn’t fill the entire gap so it’s I little bit concave. My Redguard goes to the bottom edge of the backer, right up to the silicone. First, should I have the weep holes go through the backerboard silicone or just the “finish” silicone? Second, I’m assuming I need to fill whatever gap is left behind the tile with the grout-matching silicone caulk after the tile is in place by pumping it in there. Am I correct or am I missing anything?

    Thanks.

    • Roger

      Hey Jay,

      I think the elves are drunk again. Yours is the third question lately that I know I’ve answered but my answer wasn’t posted. Sorry about that. Regarding etiquette – the only faux pas around here is taking my last beer. :D

      The entire gap between the backer and tub does not need to be filled, but it does need a continuous bead to seal it. No weep holes in the silicone between the backer and tub – only between the tile and tub. No need to fill that gap at all. It’s only a small amount of overhanging tile which you won’t (shouldn’t, anyway :D ) be walking on. It can just hang there.

      • Jay

        Yes that does sound familiar, but I didn’t make the connection with my situation. :wink:

        Thanks as always.

  • Bonnie

    Roger,

    When using Kerdi do you recommend their “movement” corners or silicone?

    ~Bonnie

    • Roger

      Hi Bonnie,

      As far as the integrity of the installation it makes no difference. If you like the look of the movement profiles, and want to pay for them, they are perfectly fine. The fit well with some installations and look forced with others. It’s purely a personal choice regarding aesthetics more than anything.

  • Mimi

    Hi, Roger,
    You do know you have a guaranteed spot in heaven for this website, right? I just got your manual for a traditional step-in shower, and my question is about the plastic sheeting barrier over the studs.

    I understand it has to overlap 2″ or more over the PVC floor membrane, but does the bottom end of the plastic have to be silicone caulked to the membrane, or can it just hang over it? Also, if my plastic can’t cover all 3 walls in one sweep & have to layer it, do those overlapping layers need to be caulked as well, or can they just hang too?

    Just hanging, Mimi

    • Roger

      Hey Mimi,

      Nothing needs to be siliconed. It all just hangs there. The backer will keep it in place and provided it’s all layered correctly no water will get into it.

      • Mimi

        Roger, thanks for the quick response! I apologize in advance for the silly questions I’ll have in the near future ’cause demo starts in 3 days.

        Confusion#2: My shower floor is concrete & my question’s about the thinset slurry to bond the Quickrete deckmud preslope to the concrete. I was planning to use white Versabond Flex Fortified Thin-set Mortar for the tiling.

        Can I use Versabond for the thinset slurry, or should I use something else?
        Any waiting time after the slurry is spread before the deck mud is placed, or can it be done immediately after?

        • Roger

          Yes, you can use the versabond. Install the deck mud over it immediately after you put it down – no waiting time.

  • Don

    Roger,

    Not sure this question fits here, but how do you handle overlapping of floor (pan)/wall tile transition. In other words, do you prefer to have the wall tile edges abut (assuming a small expansion gap) the floor (pan) tile surface or have the floor (pan) tile edge abut the wall tile surface? I’m guessing it really doesn’t matter that much, but maybe one method hides goofs better(?)

    • Roger

      Hey Don,

      I prefer the wall tile over the floor tile, but it doesn’t make any difference from a waterproofing standpoint. It’s merely a personal preference. I just think it looks better.

  • Adrian

    Roger,

    When you refer to the “lip” of the tub, are you referring to the flange that is attached to the wall (vertical) or the top of the tub (horizontal)? I’m slightly confused as to how much of a gap to leave between the top of the tub and the bottom of my substrate. I’m taking on my first tub enclosure and want to get it right the first time and not have to do it twice.

    Thanks for your help and all the information on your blog!

    Adrian

    • Roger

      Hey Adrian,

      It depends on where I referred to the lip. When referring to the tub and the lip it is the vertical portion of the tub. If shimming out the backer over the front of the lip then it would go 1/8″ above the horizontal portion. If not shimming it out it goes to about 1/16″ above the lip.

  • Chris

    Hi Roger,

    You mentioned there should be a gap between your tub and the bottom of your backerboard and furthermore, if using a topical method you mentioned to can fill the gap with silicone. Then you mentioned when it comes time to tile, you can tile right over that gap.

    I am using a topical method (liquid membrane) and am using a tub base with tile and hardiebacker on the walls. The tub has a 1-2″ lip on 3 sides.

    I was planning to slightly overlap the tub lip with backerboard. And then use silicone to cover the hardiebacker/tub lip transition. Next, I plan to apply the liquid membrane to the hardiebacker. Lastly, I plan to tile over the hardiebacker and tub lip all the way down to the tub, leaving 1/8″ gap between the tub base and tile, which will be filled in with silicone caulk.

    Does that sound about right to you?
    Thanks for your help here.
    Chris

    • Roger

      Hey Chris,

      Yup, you have it all correct. Be sure to leave weep holes in the silicone between the tile and tub when you’re done.

      • Chris

        Ok got it, forgot about weep holes, thanks! :)

        • Chris

          Hi Roger,

          My tub lip (1-2 inches high) is currently screwed into the 2×4’s, which seemed to have been part of the tub install. I am thinking I will need to waterproof over and around these screws, as I wasn’t planning to to cover the screws with the backer.

          Have you run into this before or have any thoughts as to what I should use to put over/around the screws to make them waterproof. Tile will go over them, but as I learned tile isn’t waterproof :)

          Thanks,
          Chris

          • Roger

            You can cover the heads of them with your liquid membrane. You can also cover them with just plain silicone. It is common practice to screw the tub flange into the studs.

            • Jay

              I left 1/4″ gap between the tub deck and Hardi backer board edge, which overlaps the lip. My Redguard goes to the edge of the backer, but I haven’t silconed anything yet. Do I understand correctly that I should silicone between the tub and backer board before tiling (excluding the weep holes)? Then silicone again using the grout-matching caulk after the tile is in place?

              Thanks.

              • Jay

                Oops, I was wrong. I siliconed the bottom of the backer with clear silicone before Redguard, though I didn’t fill the whole gap. I’m still assuming I’ll pump the remaining gap with finish silicone after the tile is in. Right?

                Thanks again.

                • Roger

                  The entire gap between the backer and tub does not need to be filled, but it does need a continuous bead to seal it. No weep holes in the silicone between the backer and tub – only between the tile and tub. No need to fill that gap at all. It’s only a small amount of overhanging tile which you won’t (shouldn’t, anyway :D ) be walking on. It can just hang there.

  • misty

    hi roger-
    I just finished my kerdi install on my tub shower. Kerdi fix was put at the tub lip under the drywall bottom and I think I am suppose to put caulk in the gap between the bottom tile and the tub how big should that gap be and what kind of caulk. second question is thatwhen I put my hand over the kerdi it feels like there is nothing back there I am concerned but it is stuck to the walls I pushed all the tiger strips out mortar came out also but as long as it is attached am I okay. Also I am using large tiles to hang on the wall above tub to the ceiling the onlyproblem is that I cannot find a large
    tile unmodifies TS I am using 13 by 13 tiles what do you suggest I use ? I bought tec brand unmodified will this be ok? Also how do this big tiles stay up on such a thin membrane and how long before I can tile it has been about 8 hours since I did my last kerdi band? thanks so very much for your help!1

    • Roger

      Hi Misty,

      A 1/16″ – 1/8″ gap should be left between the tile and tub and filled with 100% silicone. I don’t understand what you mean when you say it feels like there’s nothing back there. If the kerdi does not have tiger-stripes and is a consistent color from embedding it into the thinset then it’s attached. Tec unmodified it fine for your tile. You can tile now – you can begin tiling as soon as you finish installing your kerdi.

      Doesn’t matter how big individual tiles are – one square foot of a 6 foot x 6 foot tile weighs the same as a square foot of the same tile in 2 inch x 2 inch squares – one square foot is one square foot – whether they are one tile or 144 different tiles.

      • MISTY

        thanks roger for the info. I am concerned about the tiles slipping down Can I use a ledger board with the kerdi and seal up screw holes with kerdi fix? also should I start tiling up on the second row and do yhr first row last? which wall would you suggest I start with back front (with the fixtures) or the long side wall? thanks again roger and have a nice weekend.

        • Roger

          Yes, you can use a ledger board and seal the holes with kerdi-fix. I normally don’t start with the second row – I start with the first. You can if you want to, though. Start with the longest back wall which is the first seen when looking into the shower. It normally leaves a better appearance if that is the one the other walls butt up to.

  • sdemoss

    I have an older shower it is tiled about 4 feet above the tub, and it’s not high enough to take showers without getting the walls wet. Right now the walls are some kind of laminate or plastic coated backer board with tape as caulk?? What can I do with the walls and still leave the tiles alone?

    • Roger

      You’ll need to remove all that plastic board and see what you have there. I have no idea what it may be.

      • sdemoss

        I believe it will be sheetrock, what shoud I put over the sheetrock without removing any tiles and do I meet them up with caulk or what?

        • Roger

          You can use kerdi over it and place a bead of silicone at the bottom where it meets the current tile. You can also use redgard it you want. It’s not recommended but there may be no waterproofing behind the tile that is currently there anyway. :D

  • Dan

    Hi Roger,

    We are using 12″x12″ sheets of 2 1/4″ mosaic tile for our shower floor. What is the best way to cut this tile? Some recommend tile nippers, while others recommend a wet saw. If I use the wet saw, should I leave the tile attached to the sheet or remove it and cut it individually? I wouldn’t think I could get a nice clean edge with tile nippers.

    • Roger

      Hey Dan,

      A wet saw cut’s ’em just fine. I can use nippers and get a nearly perfect cut – after 21 years of practice. :D Use a wet saw.

      • Dan

        Should I leave the tiles attached to the sheet or separate them and cut them. I’m concerned that the tiles may move slightly while I’m cutting if they are attached to the sheet.

        • Roger

          I cut them on the sheet. They normally don’t move. As long as you take your time with it you’ll be fine. You can take them off if it’ll be easier for you, just seems like more work than needed to me.

          • Dan

            Thank you for the help! :D

  • ShawnyB

    Hi Roger,

    Have you ever used PVC Beadboard for the walls of a walk-in shower instead of tile ? The wife really likes the look but we’re not sure if we will end up with more problems than it’s worth ? I’ve already created the enclosure with Durock and Redgard topical membrane. Not sure how I would attach the beadboard to the membrane ? :-D

    • Roger

      Hi Shawny,

      PVC rather than tile??? Whattsa matter with your wife? :D

      I’ve never done it nor seen it done. The only thing I can think of that would not fail as a bonding agent would be epoxy. I don’t know what kind of problems you may have with an installation like that.

      I’m a lot of help, huh? :D

  • Earl

    Hi Roger, so I live in Canada and it gets kind of cold here…it probably gets chilly in Colorado too. My question is regarding the mold sandwich, if I install the kerdi right moisture shouldn’t get through to my substrate and cause this moisture problem right? I guess my concern is cutting slits in the vapour barrier that keeps the insulation from getting wet.

    Thx, Earl

    • Roger

      Hi Earl,

      Correctly installed kerdi will allow absolutely no moisture behind it – ever. You will, however, have moisture which seeps into the substrate as you are installing the kerdi, so moisture will get back there. If the plastic is left intact it will have absolutely no way to dissipate and will begin to grow mold. The insulation will not get wet if you install your kerdi properly. Kerdi will serve the same purpose once installed – it will simply be 1/2″ farther away from the insulation.

  • Damian

    Hey Roger,

    I just have some basic questions about tiling in general. I am finally getting to the stages of tiling in my bathroom remodel wooo hooo! I have been doing some research online, and I remember you saying that some of the things online are not the right way of doing things so I just have some questions to ask you.

    We are tiling the wall about half way up in the main part of the bathroom with 6″ porcelin tile with a rectangle block glass tile border in which we are going to carry both over to the shower transition for the walls in the shower, I was watching some you tube videos :whistle: and they all show as part of the step in laying wall tile to use a baton they were calling it about 1/4 of the way up the wall so that the starting course of tile could sit on so it will not move, is that baton really necessary? I am asking because I just finished my 3rd coat of redguard in my pretty red shower now and I really do not want to screw anything into my shower membrane, it’s supposed to be a water barrier and if i penitrate the water barrier then it really would not be a barrier anymore. right?

    My other question :corn: ,
    Since I am carrying the same tile over to the shower walls, I really need to make sure my grout lines or courses line up across the wall so it does’nt look like crap. the floor is at a different level of the shower about 3″, is there any tips or tricks to calculating and planning my tiling so it does not look like an idiot did this? :wtf:

    Thanks in advance for all of your help, I am very happy i stumbled upon your website because my dog would have imploded and my four cats would have shit the bed by now. also my apologies for my spelling, at work right now and not alot of time to write this.

    • Roger

      Hey Damian,

      You are correct, you’d need to fill the holes with silicone or paint more redgard over them if you use a ledger board – I don’t use them. You do not need it.

      I normally start with a full tile above the floor in the rest of the bathroom and draw a level line into the shower from that, cut the bottom row of tile in the shower to that level line. It will keep all your grout lines at the same level.

      Get back to work! :D

  • Rudy

    Hey Roger, like the ebook, but still couple of quick questions.
    1) I’m going to use Hydro Ban as my moisture barrier. Should I still use silicone in the corner of my cement board, or go ahead and tape/thinset that part too?
    2) Using porcelain tiles mix of 6″ and 12″ with a 3″ glass listello, what size trowel? Plan on using Versa Bond. Bag shows diff sizes trowels for diff size tile, but not sure what to do when mixing sizes?
    3) Liked your write-up on SprctraLock Pro Premium grout. For someone without a lot of tiling experience is it still a good way to go, or would I be better off with a non-epoxy grout? Seems like the previous tile jobs I did I had hard time with grout, mainly keeping color consistent. Do the actual installed colors look pretty close to the samples/whats shown on the box (like do you find them to look that, or do you find them to be lighter/darker)?

    • Roger

      Hi Rudy,

      Silicone the corners and tape and mud the in-plane seams. I normally use a 3/16 x 3/16 for everything, tile size doesn’t really matter too much.Epoxy is a bit more difficult to work with but the color is always an exact match to the samples – always.

  • Shannon

    Hey Roger
    I am a handyman that has never installed tile. But am for the first time doing it (Nervous YES) and was wandering what is the best silicone to use for my corners. It is ceramic. Thanks fer all the info you dish out.
    Ganeys

    • Roger

      Hi Shannon,

      You want 100% silicone. Most tile manufacturers make a silicone which matches the grout – that always looks best. But as long as it’s 100% silicone you’ll be fine.

      • Shannon

        Thanks fer the info Roger

  • Matt

    Roger,

    Thanks for your advice on managing the wall to tub transition when using kerdi-board. Interested to know if you have any experience using prefabricated shower recess like the quickshelf wall insert (i.e., http://www.quickshelf.net). Generally, would like to get your opinion on the pros/cons of using something like this. Also, would you recommend installing this with the flange over or behind the backerboard?

    Thanks,

    Matt

    • Roger

      I have used the prefabricated niches a couple of times. They work fine for what they are, but I no longer use them.

      They all work as described and are quick. The reason I don’t like them is that they are all standard sizes which never, ever match up to my tile. I prefer to build my own which I can create in any size to match my grout lines, inserts, tile size – whatever. If you use those you’re stuck with that size.

      The waterproofing of all of them rely on the flange being installed over the backerboard rather than behind it.

  • Andy

    When doing a leak test, should you expect some evaporation over a 24 hour period? I have a 48 x 41 pan and water went down about 1/8th of an inch in about 18 hours. What do you think?

    • Roger

      Hey Andy,

      It will evaporate some, but that sounds like a hell of a lot to me. Drain the pan and roll back the membrane to see if there are any wet areas either on the wall or in the deck mud of the pre-slope. It should not have gone down that much. Not saying it won’t, just saying that sounds like a bit much. Be sure to check around the drain as well.

  • Jay

    I’m wondering about overlapping tiles in the corners of my shower. I realize there will be a gap, but does it matter if the surface of one tile extends along the edge of the perpendicular tile? Think of a box join with overlapping sides. I’m thinking that the caulk may adhere better to the edge of a tile vs. the face if it. I hope I’m making sense. Maybe I’m over thinking it, but just want to be sure I get a good seal in the corners.

    Also, I was wondering about the appearance of Spectrlock. Does it look any different from typical sanded grout, i.e. would you know by looking at it that itis epoxy?

    Thanks’ I really appreciate all the great info on your site!!!

    • Roger

      Hi Jay,

      Silicone will stick to anything, including the face of the tile in the corner. As long as you get that gap full and pressed in well as you’re tooling it you will get a very good seal.

      If you look really close at the spectralock you can tell the difference, a casual observer (one not looking to see what kind of grout you have) will never notice it.

  • Amber

    Hellooo!! I love your site and have goine through each step listed in preparing my bath/shower for tile. So here I am ready to tile. I am using subway tile and currently figuring out my layout. What size gap (for caulk) do you leave between the tiles on the inside corners? Thank you!!

    Amber

    • Roger

      Helloooooooooo! (Did you just type at me in the stomach voice from Seinfeld??? :suspect: )

      1/16″ – 1/8″. I prefer 1/16″.