Well, you’ve made it to the final step. If you have arrived at this portion of the instructions without first reading the rest, start with How to Create a Shower Floor. Go ahead, I’ll be right here when you get back. I’ll just sit back and drink this beer Pepsi while I wait.
Okay, now that we’ve ensured that your shower liner is indeed waterproof and won’t leak into your dining room and carve the Grand Canyon into your basement we’re ready for the final portion. The top mud bed is the surface onto which your shower floor tile is actually installed.
What we will now be doing is fabricating your top mud bed directly over the top of your waterproof liner. The top bed will be 1 1/4″ to 1 1/2″ thick – consistent throughout from the drain to the wall. Since you have a pre-slope beneath your liner (umm, you DO have a pre-slope beneath your liner, right?) you already have the correct slope for drainage. By making a consistent mudbed for your top slope it will follow the slope for the same amount. Know what I mean?
Here, take a look at this badly created diagram and that may help explain it – and don’t give me any crap about my lack of photoshop skills! You can click on the diagram for the full-size version.
The top mud bed is what we have left for your shower provided you’ve followed in order. See how the top mud bed is properly sloped toward the drain even though it is a consistent thickness? That’s what I mean.
A couple of notes before we start making a mess. You can install your moisture barrier and backerboard on the walls at this point if you want to. DO NOT put any screws through the liner, stop them above the top of the liner. The top mud bed will hold the bottom in place if you choose to do it like this. Your moisture barrier must go over the top of your pan liner as in the diagram. This ensures that any moisture will run down into the shower rather than into your framing behind your wall.
In my wonderful diagram I have the wall substrate or backerboard installed after the top mud bed is fabricated, you can also do it in this manner. Installing it before, though, assists in getting a level perimeter around the base of your shower since you can draw lines on the wall. It’s up to you.
Determining the thickness of your top mud bed relies mostly upon the amount of vertical movement you have in your drain. You need to make sure that you can unscrew the center portion (this moves the top of the drain up) enough to be level or a hair below the top of your mudbed with tile. The easiest way to determine this is to start at 1 1/4″ – that’s just the thickness I prefer to have if possible.
You need to place pea gravel, spacers, or something similar around the drain where the weep holes are located. This prevents deck mud from clogging up your weep holes and nullifying all of your hard work. If plugged up the shower cannot properly drain beneath your floor tile and your house will fall down and your dog will burst into flames. Okay, maybe your house won’t collapse, but it won’t be a good thing. Make sure you place something there that prevents clogging of your weep holes.
Place a piece of your floor tile on the base of the drain – on the upper part of the flange – and unscrew the barrel of the drain until you reach 1 1/4 inch. As long as the barrel is still firmly screwed into the flange at this height you have enough to create a 1 1/4″ top mud bed. If the drain falls out before you reach 1 1/4″ (it won’t) – go with 1″.
Now the fun part – we’re gonna make your lines so you can see what your doing, where you need to be, and make your slope correct and consistent. Get your 2 x 4 (which is actually 3 1/2″ x 1 1/2″ – economy I guess) and set it on top of your drain (Figure 1). Measure from the liner to the top of the 2 x 4. In this photo it is (or close enough to) 4 3/4″.
You then need to make that mark at the same height all the way around the perimeter of your shower walls (figure 2). If you have installed your backerboard you can just make that mark on the wall at a height of 4 3/4″. I use a laser because I’m a big Star Wars fan and that’s how I roll. Get one, they’re great for building showers and annoying small animals. That’s a versatile tool right there!
This may look a bit confusing at first, the 2 x 4 and all, but it will make sense shortly. Or not . . .
Now we need to prepare some more deck mud. Get out your shovel and mixing box. If you need the recipe again it’s here: How to Make Deck Mud. Start with the perimeter of the shower and dump your mud in there. I always start along the back wall of the shower.
Get a good amount of deck mud packed along the walls higher than where you want it to be. Once you have a good amount packed against the wall grab your 2 x 4 and place it flat against the wall. Get your hammer and beat the deck mud down with the 2 x 4 until the top of the 2 x 4 is level with the line you’ve made on the wall or your laser line (figures 3, 4, and 5).
Simply continue to do this around the entire outside perimeter of your shower keeping all the edges level with your line. By utilizing the 2 x 4 with the laser or the drawn line you can be certain that the floor is level all the way around (Figure 6).
Some people have asked me why I have a hole in one of my 2 x 4’s. It’s a very detailed explanation – ready, pay attention – so I can hang it on a nail when I’m not using it. 
That’s all, stop overthinking everything, it’s a hole in a 2 x 4. You don’t need a hole in your 2 x 4 unless you have a storage problem.
- Figure 6
In the next post we’ll finish up your floor, fill in the center and get ready for tile!
Thanks for the very informative tutorial and especially the tips on why certain things are done or important. I looked at several other sites and they just say do this without explaining the why.
I do have a question about the construction of the curb. How does this get finished with the deck mud? The old shower I just took out had a metal grating laid on top of the liner. The curb was then formed with the deck mud. The metal grating has very sharp edges and it almost looks like it would cut the liner. Any help on the curb would be appreciated.
joejazz
Hey Joe,
The metal grating is wire lath. You cut a piece of it to fit from the bottom inside corner to the bottom outside corner, fold it into a ‘u’ shape then it gets placed over your liner on the curb. The lath holds it on there until you get mud over it. The lath attaches the mud to the curb and tile goes right to it.
Thanks for all of the great advice. I have successfully completed the pre-slope and pan installation. As I prepare to complete the top mud bed it occurs to me that I will have only the height of one 2 X 4 or less above the finished floor. That is, I stacked three 2x4s, went up the 1 1/2 inch for the pre-slope, installed liner and now, if I make a 1 1/2 inch top bed, there will only be 1 1/2 inch of space abve the finished bed on the inside of the shower curb. Is this the way it is supposed to be? When I finish the curb (3/4″ thick mortar plus thinset and tile) the height will be more like 2 1/2 inches high on the inside of the shower. Will that be okay?
Hey John,
That will be fine. I routinely have an inside curb height of 2″-3″, it’s normal.
Hi Roger,
I an now installing my Durock on the walls, 4 mill liner is behind it. My floor pan is not exactly level and I have a 1/2″gap between the floor and cement board in the middle of the wall. I also have a 1/2″ gap at the top where my durock meets the esisting drywall (which i intended to leave that way). Should I be taking this all down and redow? Or..can I fill the gap at the bottom with thinset and let dry prior to doing the floor? Would it hurt anything for me to caulk the corners prior to tiling the walls? Thanks Chris
Hey Chris,
No need to do anything with it as long as your liner on the wall overlaps the floor liner like it should. Once you get the floor tile installed that gap at the floor will be less than 1/4″. It won’t hurt to silicone the corners if you want.
Thank you. I will send a few pictures later to show the progress on my project. I really appreciate the skills you are willing to teach us on this site.
installing shower on concrete floor, using bricks for curb. and redgard for waterproofing, When covering bricks (curb) do I use thinset or the deck mud? before the redgard?? also I did get a little confused (which is not unusual for me!) on using the mesh with the redgard The mesh is use on the seams or change of plains??
Thanks Moe
Hey Moe,
You can use either. You can flush out the bricks with a skim coat of thinset and redgard over it or create a thicker curb with deck mud then redgard over it. You need to use mesh on the seams and change of planes.
In your pics where you install the top mud you make a line at 4 3/4 from the floor on the perimeter. When you beat the 2×4 down to the perimeter line the mud (or bottom of the 2/4) would be 1 1/4 from the floor (or liner) and the same height off the floor as the drain, right? I don’t understand how you get you 1/4″ per foot slope.
Hi Dominick,
Actually, it’s the same height off of the pre-slope as the drain, not the same height off of the floor. The pre-slope already has your 1/4″ per foot slope, a uniform mud deck on top of it will be sloped at 1/4″ per foot. If you slope the top mud deck as well your final slope will be 1/2″ per foot, it needs to be uniform.
Hi Roger, thanks for a great website. I had a large shower (48x 70) done. Preslope, membrane and the after slope. However, there drain seems to stick up a bit above the tile and there is another area that’s about a 24×24 inch where the water is pooling. Any way to fix that without ripping up the whole shower? Can i just rip out the tiles in the area around the drain and the other area and use either masons cement or surface leveler to raise them and retile? Or in the area around the drain shave down the drain pvc and use on of those slip in grates to bury it more? THanks for your advice
Hi Mala,
You can remove those tiles and build those areas up with layers of thinset or just mix your thinset thicker. It would be the easiest fix.
Roger,
I just found your site tonight,,,,,,after I just finished the top layer on my new shower pan. I use a pre-mixed product designed for tiling applications specifically shower pans,,,,mixed the bottom sloped layer with a little more water and it had a slighly soupy consistenceny when i appied it…..for this top layer I used less water and it is the sand like consistency that your decsribred it should have. When I appied this top layer I tamped it down and leveled (with slope),,,but your posting has me concerned because i did not “beat da hell out of it”. Should i be concerned? Thanks,,,I think you have a new fan.
Hey Chris,
I have no idea whether or not you should be concerned – I wasn’t watching you do it.
If, when it cures, you have a solid substrate and not a sandbox then you’ll likely be just fine. I over-emphasize that to get the point across, as long as it’s well packed it’s normally just fine.
Just found the answer to my question above in your previous posts … sandpaper it should be fine. So here’s a new question …. after your final motar bed has been laid, what would the minimum “safe” height of the inside of your curb? Is higher better here for keeping water out, or at least from going up onto your curb or does this not really matter if you have a glass enclosure?
thank you
Hey Nick,
Doesn’t matter too much. The code around here is minimum two inches above the finished floor surface, I don’t know what codes may apply where you are.
Sandpaper works too.
Roger, great website. I’m debating between traditional and topical methods. My tub/shower’s back wall is against an outer wall on the house with a vapor barrier (damaged by previous homeowner I’ve discovered). Do I need to remove this barrier if doing the topical method or kerdi sheet? I don’t want a mold sandwich after all. I’m replacing the fiberglass tub/shower with a tied shower. Thanks for your advice.
Pete
Tiled shower…damn iPad and stupid autocorrect.
Hey Pete,
You can just cut slits in it (if need be), it doesn’t necessarily need to be completely removed. It just needs to be able to dissipate any minute amounts of vapor which may become trapped.
Once you have finished the top motar bed, is the height adjustable drain “locked” in place or can you still unscrew and remove it? Technically, you have filled the dry pack on and around it fairly tight right, so I’m thinking that it no longer be adjusted.
P.S. great step-by-step series you’ve provided, thanks again !
Hey Nick,
If you screw and unscrew the drain 1/4 turn right after you pack the mud around it you’ll be able to unscrew the drain as needed. You can also work it back and forth after the mud cures to ‘sand’ out the deck mud with the little nubs on the bottom of the drain. You’ll then be able to unscrew it as needed.
Ok so the the pre-slope has been created (as per your instructions, lol) and she’s rock solid. Quick question about it though, she’s a little rough. I was unable to trowel it smooth and I’m probably worrying too much but I wanted to know if it’s possible that it would tear the membrane? should I lightly sand it smooth and if so with what? (I was thinking those hand stones you used to file the edges of cut tile). thoughts?
Thanks again
Hey Nick,
There is absolutely no way it’ll tear the membrane, those things are very, very strong. If you do want to sand it down some you can use a regular brick. The edging stones work also, but they clog up quickly.
I can’t seem to get rid of folds and or bubbles under my liner, I put up the backer board, but the liner curves up the wall and the excess on the curb bubbles up without pressure. Is there a way to put the mud in that will smooth out the liner? Should I be taking the backer board down and reattaching the membrane on the studs? I tried to use a 2×4 to make snug corners but the seem rounded. At the end the liner seemed to want to rise up one of the walls a little. I thought I was leaving just enough slack that the mud could weight it down into the corners but now I am concerned I may have left too much.?.
Also the liner is pretty bunched up on the curb where it curves 45 degrees, is there a trick to that? I have the “kirb perfect” kit that I am hoping will help me make an even surface over folded liner but don’t know how to get folds to be more compressed and avoid an air pocket …?
Thanks for any suggestions, I’d ideally love to make my top coat ASAP, so don’t feel you need to wait to be sober to respond. ;-)
Thanks and Cheers,
Stoph
Hey Stoph,
You got shuffled into the spam folder for some reason – you aren’t a Nigerian prince wanting my bank account to deposit untold millions, are you?
There will normally always be some space where your liner curves up, folds, etc. Packing the mud down really well takes care of that. It’ll relax after you place mud onto it. No worries. The curb-perfect should hold down your liner and allow you a flat surface as well.
And I’m never sober when I respond anyway.
I wish you had a brighter picture of the fold you did where the liner goes over the curb next to a wall. I need a view of after the cut….
Thank you so much for these posts, though I have enjoyed reading them as well as following along with my shower. I only wish I had not put up a minimal vapor barrier behind the backer board when I intended to do the redguard as well… but my backer board is already in place so I guess I am stuck with it and HD will take the Redguard back…
Cheers
Stoph
Hey Stoph,
I wish I had a brighter picture of it too!
I need to remember to take one next time I do a traditional deck. Sorry about that.
Hey Elf,
You stated in the topical waterproofing manual never to use pressure treated wood. I was always told that any wood that touches the ground ( cement) needs to not only pressure treated but also sit on an insulator ( pink foam sheet). I want to use a PT sill plate and regular lumber for all else. Also I’m using a store bought shower pan but will tile my walls. I want to install a couple of niches in the shower ( 36×48). Do I install the niches first then put up the plastic sheet sealing the sheet to the face of the niche with silicone then my Backer board?
Just so you know, maybe them mountain unicorn’s farts smell like gumdrops but the ones here in NYC farts smell like shit.
Hey Leon,
I also (I think
) stated that the rule applies only to the framing of the curb. If over concrete it needs to be build out of bricks, not any type of lumber at all, insulator or not. The walls are fine and should be built with a pt sill plate. Any movement in your wall has open space to dissipate and be transferred. If it’s under your curb the only space to do that is directly into the back of your tile.
Yes, the niches are installed exactly as you’ve described. You can also cut out the space for your niche, silicone the barrier to the back of the backer, then install your niche siliconing it to the surface of the backer. The first method is better, though.
I’m POSITIVE those are just the Brooklyn unicorns, no?
I really want to thank you for providing the best information on how to build a shower correctly. I finished the shower about one month ago and it is working perfectly thanks to your expert help. It was a challenging project, but very rewarding now that it is finished. I have pictures of the finished shower that I would like to send to you but I don’t see a link to enable me to do that.
Thanks again,
Dan
I was able to locate your upload page and upload some pictures of the shower. I did not include any of the construction pictures, only the finished product. If there is any interest in the construction pictures, I could upload some of them also.
Thanks again, Dan
Hey Dan,
That turned out great! If you would like to upload some of the in-process construction photos I’ll take those as well. It’s always helpful for people to see that there is a specific process involved and it requires more than simply sticking tiles to a wall.
Great job!
Thanks, I tried to upload the construction pictures, but received an error when I attempted to upload the first picture. The pictures are JPEG and are about 3.6MB each. It stated that I reached a memory limit of 81 MB, so I don’t know what happened. I have about 20 pictures all the same size. I could go back and downsize the size of the files, but it’s a time consuming process. If needed, I will do that.
Thanks, Dan.
Update, I was able to upload the installation pictures by reducing the size of each picture to around 400Kb. Apparently, the program does not handle files that are more than 3Mb. Anyway, this was a fun project that took about 5 months and I think it turned out great. I’m not sure what I would have done without your on-line guidance, I would have finished the project without your instruction. But you guidance really helped in letting me know that I was on the right track. Thanks again. Dan
Hey Dan,
Sorry for the delay – glad you got it worked out. I’ll need to see what to do to raise that. I didn’t know there was a limit on it. That’s what you get when a tile guy runs the site.
It turned out great! I’ll get it up on the reader’s project page here in the next couple of days or so. Thanks for uploading all that!
Thanks for your kind words. I’m pretty sure that my project will not end up on your “flawed” page. I forgot to mention that I used “LASH” guides to ensure that the tiles were installed level without any lippage. They are somewhat expensive, but they did work very well for someone that does not install tile all of the time. I’m sure you don’t need them, but they worked very well for a novice like me. I plan to use them again on any tile job that I do. Have you seen them and what do you think of them for the novice? Dan
I’ve both heard of and used the LASH system. It is a good system to limit lippage for DIY’ers. Works very well.
Hello
OK. I did an amazing job on my first slope, second slope, had that pea gravel ready but then forgot to put it in. So. those weep holes got plugged of course.
How much water makes it to those weep holes? .5%
Unless you block the drain.
It still will weep right, but just … less quickly.
It’s a second shower. Less used.
What’s your opinion?
Rip it out. Very difficult. May break the plumbing.
Drill weep holes along the second portion of the drain.
Use Red guard to make a sealant and maybe drill weep holes.
Leave it. NOt diffficult. Chance of decay.
Hey Jim,
It’s not the amount of water that gets there with each shower, it’s the amount of water that will eventually build up in there. That would be the complete saturation of the entire top deck.
I would likely chip the deck out 1 inch around the drain and get the pea gravel in there then fill in the top with deck mud. You don’t need to tear out the entire deck. If you work at it slowly the amount of sand in the deck mud will allow you to sand or chip away that portion fairly easily. Compression integrity of deck mud is extremely high, the abrasion resistance – not so much.
Thank you so much for your website, it is very helpful and funny! I just passed the inspection of my liner and I did it following the instructions on your website! My husband is so proud of me, and I’m proud of myself also! I did it all by myself! I have a coworker who is a former professional plumber and he says pouring a custom shower pan is one of the hardest plumbing tasks to do but with your help, it wasn’t hard at all, just time consuming. So thank you! But, I do have a question . . . I worked so hard to make sure my liner doesn’t leak and now I’m getting ready to put the metal lath on the curb (I have a double curb) so I can put in the final slope. Do you have any tips on how to do this without puncturing the liner? I am scared of puncturing the liner with the cut edge of the lath. I read that the lath should only come down to within an inch of the pre-slope which should help but I’m still afraid of puncturing the inside of the curb. Any tips would be appreciated. Thank you very much!
Hey Kim,
Congrats!
Don’t be overly nervous about the lath and liner. Those liners are a hell of a lot more durable than most people think. You almost have to TRY to puncture it. Just take your time and pay attention to it – you’ll be fine.
Hi, Roger, sorry for the delay in writing to you but I had quite a bit of work to get done before I was ready for the top slope — but the moment came today! You were right; I was careful about cutting the lath and then placing it over the liner and it wasn’t a big deal at all. Thanks so much for all of your help! I read some of your other pages and they were really helpful. For example, I did not know that you are not supposed to use a plastic vapor barrier behind the cement board in addition to the redguard (so I used felt paper behind the cement board and will put on the redguard after the top slope is set (but not applying it to the top slope). I also did know the difference between thinset and mortor but now I do! Thanks so much!
OK, I am sorry to bother you but as I was staring at my shower pan top slope I realize I have another question. While the top slope is setting up, I unscrewed the barrel of the drain to raise it. My tile is 3/8 inch and considering the thinset, I raised it 5/8 of an inch. But doing this, there is a void now underneath the barrel. Should I fill this? Do I need to pack this with deck mud also or just tile on top of the top slope and not worry about it? Sorry, it must seem like such a dumb question to you, but I just want to make sure I do it right! Thanks so much!!!
I don’t understand what you mean by ‘void under the barrel’? Do you mean it’s unscrewed all the way and no longer attached to the lower flange?
Hi, Roger! The barrel is still attached but when I installed the top slope with the barrel lowered I packed the deck mud around the barrel but now that it is raised, there is no deck mud around the barrel where it is now raised. Does that make sense? I can try to send you a picture if that would help you. It’s dark now (I don’t have electrical in the room) so I’d have to send it to you tomorrow. Thanks so much for your time and info!
Ah – I gotcha. Where the barrel was embedded into the deck mud before you raised it. Sorry, not enough beer last night.
Just fill that divot with thinset either as you install the floor tile or (better and easier) raise the barrel to where you need it and level it out with thinset then let it cure. The second way doesn’t require you trying to lay mosaics over a lot of thinset.
Hi, Roger, thanks so much for your reply and advice. I’m glad you understood what I was talking about — I was wondering if maybe I didn’t follow the instuctions correctly and did something wrong. Anyway, I posted 2 pictures for your viewing pleasure. If something looks all jacked up and wrong, can you please tell me now before I tile it? Anyway, thanks so much; I could not have done all this work without you! BTW, I viewed your “flawed” page and it was incredible. It made me feel like I am super awesome! Thanks again
Hi Kim,
You are super awesome! Very good looking shower base. Nice solid curb as well. Don’t forget to send pictures when you’re all finished too!
Hi Roger,
I’m using Noble Pro-Slope for my preslope. Should I glue it to the floor or what?
Then I’m using Noble Chloraloy for the waterproof membrane, then a mud layer over that. Should I put some steel lath reinforcing in the top mud layer?
Thanks for your help!
Don
Hey Don,
No need for the steel lath in your mud unless your floor is larger than about 25 square feet or so. Smaller than that – don’t worry about it.
I would use thinset to adhere it to the substrate. Noble is fairly vague on this point, but I do know you don’t wanna use construction adhesive – it melts them.
I don’t wanna talk about it, either.
Thanks for all your help thus far in my shower project. The top layer of deck mud is down and cured. The top is very sandy. I am wondering if there is a recommended technique for applying the tile cement to this surface? I wonder how well the tiles will stick with the cement adhered to some loose sand. Again, thanks, this site has much improved my project.
Hi Jamie,
You can mix up some thinset a little runnier and skim over the top with the flat side of your trowel to lock all the loose sand. It’s supposed to be sandy, that’s completely normal. As cement (in the thinset) cures it grows little crystal ‘fingers’ which lock into whatever substrate it’s installed upon. This locks the thinset into the substrate as well as the back of the tile. It will adhere just fine. Not only does the cement in the thinset do this, the cement in the deck mud continues to do this as well (mostly in the first 28 days) so they essentially lock together with a crystal matrix.
Didn’t know tile had any connection to Star Wars, did ‘ya?
What do I do about the ceiling above the shoiwer part and if I want to put granite slabs on the walls and the floor what should I put on the walls behind the granite and how do I slop the floor for the granite slabs. The shower is 591/4 x36 wide by Im thinking going write to the ceiling with the granite Thank-you
Hi Gino,
You’ll need to create a flat plane on your shower floor if you want to use slab granite there – which will require a linear drain at one end of it. Keep in mind as well, one large slab of granite on your shower floor is going to be extremely slippery. I would not recommend that at all.
The shower wall can be prepared in any manner you choose just as if you were installing tile. Any of the membrane methods will work. You don’t need to do anything special with the ceiling at all.
Roger,
Your tip about adding the width of the 2X4 to the depth of the deck mud is brilliant! So simple. yet works so well. Easily the best tip I’ve found during this whole project!
Now that I have the top layer down, I need to mud the curb. Liner and lath are already installed, and I am planning on using mason’s mix. Should I be concerned about the mason’s mix properly adhering to the deck mud. If so, how should I handle it, thinset slurry?
Thanks!
Ed
Hey Ed,
No worries – it will stick just fine to the deck mud.
Hey there! Awesome site! I am attempting to do 2 shower’s in my new house…and I have researching this to no end. I am so happy that I was given your site, it has helped me understand so much more…BUT…I am feeling really stupid about the weep holes. I’m not getting it…I understand the point of the weep holes, and I saw that you put on their about putting spacers or pea gravel etc so that they don’t get clogged…get it (sorta?)…what I’m not getting is…and I’m sure this going to sound really stupid to you…but I am soooo new at all of this…anyway…if I am putting the deck mud up to the drain, where the weep holes are…and there are spacers there…if I leave the spacers in there…wouldn’t the spacers block the holes? I am so confused! The weep holes are under the top layer…yes?
The weep holes are beneath the top mud deck so – yes!
The spacers or gravel is there to prevent the weep holes from being clogged by deck mud. The weep holes are normally less than 1/8″ wide or high – deck mud can get in there and clog them, spacers or pea gravel will not. Water can still get around the spacers or gravel and through the weep holes. Deck mud can actually clog them and prohibit water from getting to them.
That doesn’t sound stupid to me at all! You know what sounds stupid to me? The phrase ‘I, personally…’ it simply sounds redundant and bugs the shit out of me. If you start a sentence with ‘I…” aren’t you speaking of the personal ‘I’, or am I missing something??? THAT sounds stupid to me.
Oh, Roger, my dear sweet Roger. I made a huge mistake!!! Before I met you I was seeing alot of other shower building sites. The truth is I was a “How to build a tile shower” google whore! Anyway, all the other guys told me to build the curb out of pressure treated 2×4’s so that is what I did. I am building my shower on a basement cement floor. I don’t fully understand the problem. I had to frame the walls with pressure treated 2x4s against the floor so why can’t they be on the curb. I have already made the preslope and put in the liner. I can’t rip it out, I would rather die! What would be the 2nd best thing to do? If only I had met you sooner! I now know you are the only one for me!
Oops.
The problem with using pressure treated wood is that as it dissipates moisture (it’s infused with moisture on purpose) it will begin to dry and twist and warp. Once that happens anything installed over it will begin to move. Tile doesn’t like movement. You can see all sorts of pictures on my flawed page of showers I’ve torn out – every one of them that had cracking on the curb had pressure treated wood beneath it – every one.
The only proper way to fix it is to replace that curb with bricks. You can fold the liner back over and rock the wood back and forth until it comes loose from the pre-slope – it shouldn’t be stuck well at all, deck mud won’t hold onto it. Then replace it with bricks and finish everything as normal. If you think you’d rather die than do that think about how you’re gonna feel when you get all that beautiful tile installed then your curb starts cracking. You really need to replace that or the curb will not last. I know it sucks.
On a totally unrelated note: the phrase ‘google whore’ made me laugh my ass off – thanks.
I LOVE YOU! I have read through most of your site and I find it annoying when someone asks a question that you just covered in the article just above. I think to myself, “asshole, read the article.” Well, now I am going to be that asshole. I just want to make sure I have this right. I framed the walls, built the curb, poured the perslope, and have the liner in place 8-10″ up the walls and over the curb. Now, do I hang the cement board and bury the bottom of the cement baord in the top mud bed? This makes more sense to me than leaving a gap between the floor and substrate. Thanks
I love you too, asshole.
I actually didn’t cover that – so thanks. It is much easier to bury the backerboard in the top mud deck. Make sure you leave about a 1/2″ gap between the backer and your liner at the bottom. You want the water to run down and into the drain rather than wicking up the board – if the board is setting on the liner it will wick water up from it. The top mud bed will hold the bottom of the wall in place so you don’t need to screw through your liner.
Just so you know – I think that to myself all the time too!
I know you mention packing the top layer really hard. So, should I pack the top mud bed into that 1/2″ gap?
Hi Betty,
Yes, pack the mud into the gap at the bottom too.
I love your website…you do great work. Possibly the best shower information on the web!
I hired a co worker (any red flags yet?) to do my shower. He removed the old tile (to studs), and there was some evidence of minor mold. When he removed the existing preslope, it revealed a concrete floor. I asked him to move the drain to the center, since the shower is being made wider. He proceded to bang it out and made the hole about 18 inches around.
From what I saw, the entire concrete shower floor was originally poured over sand and I am guessing that there was a previous sunken tiled bathtub there because the of the tile at the bottom of the sand! We were able to cut the drain and relocate it.
We set the drain, we packed new sand around the new drain and made sure it was level with the bottom of the broken concrete. THe hole was filled with new concrete. Should I have used rebar in the new concrete?
The preslope wa done and I had to explain a lot of things to my friend. I landed up re-doing the preslope because he did not mix enough mud to complete it and used a different mix to finish it!. I am quite sure there is a straight (not level…lol) pre-slope. I am at the water barrier stage, but thought I would ask the question about the patched hole job we used to move the drain. If it is wrong, now would be the best time to get it right.
Hey Paul,
Sometimes I reinforce it and sometimes I don’t, it just depends on the job. As long as your sand bed below the drain was filled in and packed in really tightly there really shouldn’t be a problem with it. I would make sure your top mud deck is at least 1 1/2″ thick at the drain and pack it in there really well – beat the hell out of it.
Thank you Roger, for taking time from your busy day to reply so quickly (to all of us)
I am fairly confident that the sand was compacted well and the patch will hold. My next dilemna concerns the moisture barrier.
My friend has installed some hardiback from the ceiling line, but not all the way to the bottom. He also cut-out a niche on the backwall (between studs, and has already nailed the hardibacker. I made sure he framed the bottom (of the niche) with a slight downward slope. Should I have him remove the new hardibacker and install a moisture barrier between the studs and hardibacker (including the niche)? He bought a small tub of Mapei Mapelasiic Aqua Defense. I believe his intent is to paint it on the hardibacker , after the seams have all been taped and sealed. Which is better…the barrier between the studs, or the painted barrier over the hardibacker?
Alow me to thank you, in advance, for your assistance.
Hey Paul,
The Mapelastic is actually better. It’s what is called a topical waterproofing membrane. I simply places your waterproof layer directly behind your tile rather than behind your backerboard. Using topical methods eliminate any water from ever reaching your backerboard, let alone your studs. Keep in mind that for liquid topical membranes to be effective they need to be thick – about as thick as a credit card – so it requires a couple of coats. You also want to do a priming layer. Read the article about Installing Redgard on your Shower Walls Redgard and Mapelastic work the same so that applies to your situation as well.
Topical waterproofing is always best but it must be done correctly to waterproof your shower.
Hi Greg,
First off – thanks for the in depth tutorial.
After laying down the liner should I install the cement board on the walls and then start fabricating the second shower bed or create the second shower bed and then install the cement board? Which is better?
thanks!
Hi Vince – My name is Roger but you can call me Greg if you want to.
There really is no ‘correct’ way to do it. A lot of guys prefer to finish the top bed then install the cement board with a 1/4″ gap at the bottom to eliminate wicking – hardibacker (as well as all others) will wick water – hardi is the worst. I prefer to install the cement board first then the top mud bed – two reasons: The top mud bed packed against the board will keep the bottom portion (which you cannot screw through) held in place and you can mark your level lines right on the cement board. I waterproof my showers completely so when the cement board does wick water it doesn’t affect anything at all. I think that way is better – but a lot of guys disagree.
howdy,
i’ve enjoyed reading your tutorial. but i have a question. i want to just have a cement/concrete finish (no tile). what is my mix and/or what do you think about this?
sincerely greg
Hi Greg,
Personally I wouldn’t do it. But I’m biased toward tile for some odd reason
If you want simply a concrete shower floor the only option I can think of would be a specialized concrete sealer made specifically for that purpose. Deck mud is not anything close to what you want and the manufacturer of any aforementioned sealer would more than likely require a specific mix of concrete for their product.
I did find this: Waterproofing beyond topical solutions You may want to check out that link, I don’t know if that will help or not.
If you change your mind and decide you want tile in your shower – I’ll be right here.
roger,
thank you for your speedy response.
krystal is an interesting product. i’ll have to remember it. but i have already completed the mortar bed today and this product mentions skipping that process. but i suppose this extra step could only be a good thing.
the problem of not using tile is the wicking of water through the concrete and sealing this sounds like the issue. is that right?
do you know any quality products for sealing concrete.
sincerely greg
Hey Greg,
Yes, the problem is topically (or otherwise) sealing the concrete to allow any water in the shower, basin, or whatever, to flow only down into the drain without wicking through the concrete and into framing, etc.
To be honest I have no idea what I would use. I do the complete opposite with concrete. If it is sealed I will scarify it to remove the sealer in order to guarantee a bond of my mortar. I’m sure there are products available but I don’t know what they would be.
The best option, I think, would be to check out the concrete network. Anything I’ve ever needed to know about concrete I can find there. It should be able to help you out as well.