The following five-part series gives a basic overview of building a shower floor for tile. If you would like a complete step-by-step of the entire process with all the little idiosyncrasies and details I now have manuals describing the complete process for you from bare wall studs all the way up to a completely waterproof shower substrate for your tile.
If you are tiling your walls and floor you can find that one here: Waterproof shower floor and wall manual.
If you have a tub or pre-formed shower base and are only tiling the walls you can find that one here: Waterproof shower walls manual.
Curb and Pre-slope
Properly built shower
There are a couple of options to create a shower floor for tile using deck mud. The first is a single-layer shower floor which can then be coated with RedGard or a similar product or covered with kerdi to waterproof it. The other is a normal shower floor with a liner which will have two layers – a preslope, the liner, then the top slope which is then tiled. This series of posts will describe the latter.
Before we start I should note that unless you are using the kerdi waterproofing method or utilizing a liquid membrane as your floor liner you should not have the backerboard installed in the bottom part of the shower. Your waterproof membrane for a shower floor will be installed behind your backerboard. The curb and pre-slope need to be completed before installing the lower wall substrate.
Creating the curb for a wooden floor
The first thing you must do is create the outside curb of your shower. You need to create the “box” which will become the inside of your shower floor. Depending upon whether your shower will be created on a wood or concrete floor will dictate what material you use for your curb.
If you have a wooden floor you want to use regular dimensional lumber. The 2 x 4’s they carry at Home Depot – those. That is the easiest and most readily available material. Ideally you want to use kiln-dried lumber. That is lumber that is, well, dried in a kiln. By removing moisture in this manner the moisture content of KD lumber is normally between six and eight percent compared to regular dimensional lumber at close to 15%. Why does that matter? Well moisture and wood don’t mix. As it dries wood has a tendency to warp and twist. The less moisture initially in the wood the better. KD lumber is best and regular air-dried dimensional lumber is also acceptable. NEVER use pressure treated lumber – ever.
I usually use three or more stacked 2 x 4’s to create my curb depending on the size of the shower. Simply screw the first one to the floor (with correct non-corrosive screws), stack the next one on top and screw it down, and so on until the desired height is reached. That easy.
Creating the curb for a concrete floor
Using Bricks for a shower cub
For a concrete floor you want to use bricks. Yeah, bricks. Just stack ’em. I use gray concrete bricks (no holes) and stack them two or three high for my curbs. You can use just regular thinset to adhere them to the floor and to each other. Just stack them in the shape you want.
You do not want to use wood for your curb on concrete. Wood will actually absorb moisture from your concrete and start to swell.
Creating the pre-slope
This is one of the steps most often skipped by a lot of people – amateurs as well as professionals. It is imperative! You need it – it’s that simple. Without a pre-slope your waterproof liner will lay flat on the floor. This does not give water anywhere to go. It will sit there, stagnate, mold, . . . you get the idea. With a proper pre-slope any water will drain to the weep holes in the drain and go where it needs to – away.
Lathe installation for wood floor
You need to first make sure your shower floor will stay where you put it. On wood you can use regular metal lathe.
You need to place what is called a ‘cleavage’ membrane beneath your lathe. This is just a sheet of plastic or tar paper stapled to your wood floor first with the lathe placed over it. The membrane does not make anything waterproof! If someone tells you that hit ’em in the head with a bat. It is necessary to prevent the wooden floor from sucking the moisture out of the pre-slope prematurely causing it to cure too fast (or not fully) and significantly weakening it.
When your membrane is down staple the lathe over the top of that. Just cut it to the shape of your shower floor and lay it flat on the floor and staple or nail it down. This gives your mud bed something to grab onto. In the above photo I have used plastic as my membrane and only have a partial piece of lathe in – make sure you cover the entire area below your pre-slope.
A properly prepared pre-slope
For a concrete floor you need to mix up some regular thinset except you need to mix it “loose”. That just means you need to add a bit more water than the instructions call for to make it thinner. Cover your shower floor area with this before you start installing your deck mud. The deck mud itself does not “stick” to anything, you need to supply something that will adhere it to your substrate.
Oh crap – Math???
To make the installation easier you’ll want to mark your height lines on your wall studs. To figure out how high it needs to be off the floor you need to figure out your slope. This involves a bit of math – don’t panic! It’s easy. Figure out which corner is farthest from the center of your drain. Your slope needs to go up in height 1/4″ for every foot. If your furthest corner is three feet from your drain center your slope needs to rise 3/4″. Easy enough so far, right?
Your finished floor (after your liner and top mud bed are installed) needs to be 1″ to 1 1/4″ thick at the drain. So, if we make the pre-slope 3/4″ thick at the drain it needs to be a total of 1 1/2 inch thick at all your walls. So mark a line 1 1/2″ from the floor all the way around the wall studs. This will be the height of your pre-slope at the walls. I try to make my pre-slope the correct thickness at the drain so it will be 1 1/2″ at the walls. This way you do not need to draw lines, just level your perimeter with the top of the 2 x 4 studs along the bottom of the wall. Depending on the size of the shower it doesn’t always work, but it saves time if you can work it out that way.
If your shower is not a square, and they rarely are, you still need to have the same thickness at the walls all the way around the perimeter. This means that you will have a steeper slope on the walls closer to the drain. This is normal. If you don’t do it this way you will have uneven tile cuts at the bottom of your wall. By doing it this way you will ensure a level line and, in turn, a level floor around your perimeter.
The height of your pre-slope at the drain can vary. It needs to be level with the top of the bottom flange of your drain. Regular drains have two flanges which bolt to each other. The pre-slope needs to be at least level or a touch higher than the bottom flange. Your liner then goes between the top and bottom flange to utilize the weep holes in the drain. This allows any water atop the liner to drain. The pre-slope supports the liner so it needs to be level or above every point of the lower flange. Does that make sense?
This is why planning is so important. Your drain needs to be high (or low) enough and your curb needs to be higher than your shower floor – naturally. So figure all this out before you build anything.
Playing with mud
Now we need to mix up a batch of deck mud. Check out that link, I’ll wait . . .
Okay, once your mud is mixed up you want to start packing it in there. If you are going over concrete and have your thinset slurry down, cover the entire bottom of the shower floor first to ensure the entire base will stick. If you have a large shower only spread as much thinset as you can reach over at a time. Start at the walls and pack your mud down really well – beat the hell out of it. Seriously, beat it like the last DMV employee you spoke with. You want to eliminate any voids and create as dense a bed as possible. Don’t worry, it won’t hit back.
Pack it down around the perimeter to just above your line. When you get that done get yourself a 2 x 4 about 18 – 24 inches long. Lay that on top of your mud bed against your wall and tap the 2 x 4 down with your hammer until it is even with your line. This ensures a level, even line all the way around your perimeter. Perfect! Now don’t touch the edges.
Properly prepared deck mud
Continue to pack mud into your shower base all the way from the perimeter down to the drain. You should have a straight line from the perimeter to the drain without any dips or humps. This will allow water to drain correctly without pooling anywhere. While this particular layer of your shower floor does not have to be exact, you do need to make certain it is fairly flat in regards to the line from the perimeter to the drain.
Ensure a consistent slope
That’s it. When you get it all packed in there it should have a shape similar to a very, very shallow bowl. Now leave it alone. Really, leave it alone. The next day it will be ready to install your liner and all that fun stuff. Don’t play with it until then.
In my next post I will show you how to install your waterproof liner. Until then leave your pre-slope alone. It’s fine. Quit trying to perfect it. We’ll do that tomorrow. Get away from it. Really. Stop staring at it . . .
Read this next if I haven’t already bored you to death: How to create a shower floor Part 2
Ack! My plumber installed the shower floor membrane directly on the subfloor telling me a pre-slope was not needed. I went ahead and did the deck mud then found your site (totally addictive, by the way) and have a conundrum: I would like to avoid tearing up the concrete and membrane although it probably needs to be re-done. I have not yet tiled. I have 4 mil plastic between the studs and Hardiebacker on the walls. Will I have mold in the corners of the shower floor because there is no pre-slope? Would RedGard on the membrane under the 4mil plastic and covering the mud deck prevent it?
Hi Julie,
It needs to be redone. It NEEDS a preslope. It is required. Redgard would waterproof it but it will also create a problem with the membrane beneath it. That will grow mold as well. If you don’t have a preslope you will eventually have mold. Your ‘plumber’ is incorrect. Removing what is currently there is the only way to properly fix it.
Thanks, Roger.
We are having our contractor install Laticrete HydroBan and a Laticrete HydroBan shower flange drain. It is the first time he is working with these materials. He has constructed the shower pan and installed a curb made of 2×4’s and covered the floor and curb with Hardibacker. Today he installed the HydroBan flange drain and laid the mortar bed. He did not cover the curb with mortar. Based on the Laticrete video they show the curb being covered with lath and mortar. Does the curb need mortar or can the Hydroban just be applied directly to the Hardibacker covered curb?
Hi Michelle,
The hydroban can go directly onto the backerboard for the curb.
No standing water, Thank goodness, but didn’t know if the vapor transmission would effect the deck mud. Thanks so much for ur help:))
We bought a house that was once a garage, the first floor is on a concrete slab and we to dig up the whole back of the house to waterproof the outside because ground level is at the bottom of the windows on the back side of the house. That is where the bathroom is, on the back side of the house. But we still have to find a way to fix the problem of dampness coming up through the slab back there. There was a cast iron bathtub in there when we gutted the bathroom we toar it out to put shower in there. I have been reading and reading on how to make a custom shower pan, but really really don’t want to screw this up:) lol. I do know that to much water added to deck mud makes it not as strong so didn’t know if the dampness would affect the strength of the shower pan. Thank you so much for ur quick response:) any thing else I should know don’t hesitate to type, I’m all eyes:))
Hi Nichole,
How much ‘dampness’? Regular vapor transmission from a slab is not going to affect your mudbed at all. It will not weaken it. Unless you actually have standing water or surface water from the slab’s vapor transmission it won’t be a problem.
I don’t know if you still read these comments but praying that you do:) I have a question about my concrete slab subfloor for my shower. My shower is framed and curb built, but my shower subfloor is not level and and is damp. Not wet but damp. So I guess my question to you Master Jedi is does my subfloor need to be leveled and completely dry before installing my pre-slope? Any help would be greatly appreciated:)
Awaiting your instruction sincerely,
Young Padawan
Hi Nichole,
No prayer needed, I answer all the questions on my site. Your floor does not need to be level, you can create the slope in whatever manner you want with deck mud. It can be an inch out of level and you can use deck mud to create a proper slope. Why is your floor damp? Normally you can go over it when it’s damp unless the moisture is an underlying problem with the concrete. Even then you can create your shower floor, but it will dictate what type of waterproofing you’re able to successfully utilize on the shower floor.
This is great information, even for those of us who are not brave enough to do the project themselves. Thank you.
A basic question that I hope you are willing to help with:
We have an existing traditional shower. However we have to replace the corroded p-trap. So now is the time to update the tile and enlarge the shower too. The curb and deck will be demolished to create a shorter curb and re-hotmop. The existing tiles are easily popping off the walls and the underlying mortar bed is in great shape. There are not even pock marks on the walls.
Our question is: Is it necessary to demo all the walls too? Or can we just demo down about a foot from the floor and just replace what needs replacing?
Thanks so much for your time.
We We are in the process of demolition. of the curb and the original deck. The new shower will be slightly larger.
Hi W – if that is your real name…
You can just replace as far up as you need to replace if you want to. No need to demo everything if it’s in good shape and correctly waterproofed.
Excellent! Thanks for your help!
Hi,
On a concrete slab floor, should I let the loose scratchcoat of thinset dry before installing deck mud preslope? Or just mix it loose, coat the floor, and put down the deck mud while the thinset is still wet? I hope my question makes sense. Your website is awesome!
Mike
Hey Mike,
You need to install the mud over the thinset before it cures so it will bond it to the floor.
Hi, I can’t find the instructions on how to tile the shower curb. The instructions for the deck mud only seem to cover the floor. What do I do with the vertical part of the shower curb covered by the liner? Do I apply deck mud there too? And also what about the top of the shower curb covered with the liner? Do I apply deck mud on it too? If so, how much?
If you point out to me which manual contains that info I would look at it.Thank you!
Hi JC,
You need to mix up wet mud (which is just deck mud with 1/2 – 1 part masonry lime) and form the curb with that. It’s essentially sticky deck mud. You should have wire lath over the liner, the wet mud goes directly to it then the tile is installed right to the cured mud. The traditional wall and shower floor manual covers it.
Roger
I’ve purchased your books and am ready to do the deck mud, but live in Alaska, which when they the “LAST FRONTIER” they ain’t kidding!! I can not find any of the products you talk about. We do have the two big Home Material stores, but only carry Sakrete Brand. I can get Sakrete 80# Type S Mortar Mix or Lafarge 94# Portland Cement Type I-II and AS&G All-purpose Sand, or Quikrete 50# Play Sand. The FAT MUD lime choice is: Type S Lime or Hydrated Mason Lime. Which of these could I use? Also can not find the metal Lath anywhere with-in 200 miles, what else could I use. I want to get this project done. Thanks
Roger, thanks for your website. I apologize in advance as I’m sure you’ve answered my questions but have been unable to locate those previous inquiries. I’ve decided to demo and re-tile a 32×60 shower on slab opting for the topical water proofing method (purchased your manual). My questions below:
1. Mud deck to backer board transition; do you treat this like any other inside corner with thinset/tape?
2. Mud deck to brick curb transition; same as #1?
3. How thick should slurry be between slab and new deck?
4. Install mud deck while slurry is wet?
Thanks a bunch.
Hey Chris,
1. No need to tape and mud at the mud deck.
2. Same as #1.
3. 3/16″ to 1/4″
4. Yes.
Hey,
The contractor who did this step left 3 or so spots that collect water in puddles, (bad sloping). Any suggestions to remedy this? Thanks
Hey Robert,
If they are less than 1/4″ off you can float it out with thinset. If they are more than 1/4″ you can put thinset down and add more deck mud.
HI
I am panicking, so i am pretty sure my plumber does not do the “pre slope” on the shower floor, and just installs the rubber membrane, so now i am freaking because how do I tell a professional that this is what he is suppossed to do, i am a female homeowner who has just done a lot of research! SHould i just use the kerdi system on shower floor or see if my tile installer can take care of the entire floor?
Also for vanity backsplash do I need to install backerboard on the wall before the tile?
What is the standard height for backsplash tile on a vanity if you dont do it all the way up? 4 inches?
Thanks for your time
Thank You
Cheri
Hi Cheri,
You would not be telling a professional how to do his job. Professionals know that a properly built shower floor requires a preslope. He may be a professional plumber but he obviously does not know how to build a shower properly. I would talk to your tile guy, he likely has more knowledge about it than your plumber. Another point: you are PAYING him to do a job for YOU. Tell him you want your shower built properly with a preslope or you’ll find someone who will.
You can install the tile onto the drywall, you don’t need backerboard for a backsplash. Heights vary wildly, it depends on what you think looks good, not what everyone else does. Four to six inches is average.
I am about to begin laying the preslope for my shower which is on concrete. My prior shower was one of those prefab shower pan and sides. We pulled that out and now there is just the flat slab and the PVC pipe sticking straight up about 6 inches. I think I will need to cut the PVC pipe down before beginning the preslope correct? Is there a height it should be at initially? The shower is a 36×62 shower with the drain offset to the left. I have read a lot about 1/4″ slope for every foot for the actually drain mechanism but what should the initial height of the PVC pipe coming up be? Thank you in advance!
Michele
MN
Hey Michele,
You should have your drain installed onto the drain pipe before you begin creating your pre-slope. The height at which you cut it depends on the particular drain you’re using. You want the bottom flange of the drain to be 1/4″ – 3/4″ off the concrete. That will be the minimum height of your mud deck at the drain, which will rise 1/4″ / foot from there. When you measure the drain don’t forget that the drain pipe will actually go inside the bottom of the drain about an inch. Be sure to take that into consideration and don’t cut it too short.
What I normally do is place the drain on the top of the drain pipe, as it sits now, measure the height of the bottom flange to the cement and that measurement, minus the height you want the bottom flange, is how much you’ll cut off the drain pipe.
Roger:
Shower is almost finish, used glass mosaic tiles on the walls, and river rock for the floor, Just have to seal grout & floor, & put in glass panel, and it should be finish, Thanks for all you help, I learn a lot!
Roger,
Thanks for the site … LOVE all of the info!
Question…. I’m a little confused. For a traditional shower floor, is the pvc liner sandwiched between two mud decks (not sure if that’s the right term)?
I’d really like to give the Kerdi a try, but I’m afraid my plumber isn’t familiar with it and will probably do a traditional floor – I don’t feel comfortable enough to do the sloped substrate.
I’m guessing that I can’t put the Kerdi over the traditional floor because this will cause a “mold sandwich” … is that a correct assumption? Guess that was more than one questions. Thanks for your help! Lisa.
Hi Lisa,
Yes. To all your questions. Actually you had no questions to which you did not already have the answer.
Guess it’s time for me to retire! My work here is done…
Roger, no please don’t retire yet … Actually, I’d rather you were doing this than me struggling with it. I only have more questions …
For example, is the pre-slope 1/4 inch for every foot AND the final slope is also 1/4 inch for every foot?
Also, if we had the drain moved, do we need to cover and support this before anything? My gut tells me, “he’ll yeah,” but our guy said, “it’s no biggie.” But then he didn’t seem to think a pre slope was necessary … So glad you’re around! Thanks again, Lisa.
Ok – my fault. I should have gone back and read BEFORE I ask questions … No wonder you like beer … I’ d drink more if I had to answer stupid questions like mine …(just saw one about removing the pea gravel … At least it’s reassuring that I’m not alone in asking silly stuff)! So much for your work being done.
Does that mean you’ve answered those questions as well?
Pre-slope is 1/4″ per foot, top slope is consistent thickness, although since it lies on top of the pre-slope it will be sloped at 1/4″ per foot as well. Dunno what you mean by cover and support your drain? More beer!
I do not drink beer because I answer silly questions, I drink beer because beer is GOOD! (And I happen to live smack dab in the middle of Fort Collins which is one of the best brew towns in the nation). The fact that beer helps relieve the stress of answering silly questions is just a pleasant side effect.
Oh – not clear … He had to move the drain because we expanded the shower and put in a bench. Now there’s a hole in our sub-floor where the old drain used to be.
Thanks for the clarification on the slopes.
Nice part of the country – love Estes!
Oh yeah … When I went back to read I was wondering why you say to never use PT lumber on the curb?
Hell yes that needs to be supported – what the hell is wrong with your tile guy?
Long answer: PT lumber is infused with vapor in order to prevent it from soaking in more moisture in applications like decks – it won’t swell when it rains because the grains of the wood are already expanded and will not absorb moisture to the amount it takes to swell it. If you use it for your curb (and your shower is properly waterproofed) it will not be exposed to moisture. This means the PT lumber can dry out, there is no vapor stabilization as there would be in an exterior application. This cause the PT lumber to release the vapor it’s infused with. When wood releases moisture it can shrink, twist and warp. This will cause your curb to move and your tile to be compromised.
Short answer: PT lumber shrinks.
Estes is where I go to get away at least two weeks every year – love it.
The tile guy is the plumber … Starting to look like I’m the tile guy (only one who’s interested in researching/doing it right … Plus I have done our kitchen floor and backsplash, as well as helping with a large family room and bath floors in another house). Too bad I tore up my acl 7 months ago – I really want to get in there and do more!
Question about the Durock on the floor (we use hardiebacker in the kitchen) … Do we HAVE to use mortar under it? it’s in an upstairs closet and long, narrow bath. I think I overheard “the guys” talking about going without or using some kind of caulk adhesive.
Thanks for all your time and patience – It’s really appreciated!
Yes, thinset NEEDS to be used beneath it. It is there to fully support it so there are absolutely no voids. Voids are weak areas and will move when walked on. That cracks tile and grout. If they use a construction adhesive from a tube they are essentially creating MORE voids beneath the backer. It is not there to bond the backer, it is there to support it.
Roger:
Put in my pre-slope floor last Sat. I can see some flat spots, What i would like to do after 72 hrs. is put a thin (sloppy) coat of thinset, And go over the entire floor with a thin coat of deck mud to smooth and level the floor (or flat spots) Would this be advisable? Wish I had seen that device that goes into the drain, to help make the preslope , before putting the deck in.
thanks for the help Moe
Hey Moe,
A thin layer of deck mud will not be stable. You can, however, just mix up some thinset and make a thin layer of thinset over the top, that will work fine.
Roger: On the divot drain: the weep holes are on the bottom of the top flange? If I put a continuous bead of silicone around the out side of the bolts on the bottom flange, Will it not plug up the weep holes?? Putting in the pre slope tomorrow, hope all goes well, have already redguard the walls, so hopefully we will finish the pre-slope tomorrow, wait 72 hrs or better, and then finish with the redguard.
thanks Moe
Hey Moe,
The weep holes are either around the sides of the top flange or in the top of the top flange. If you’re using the divot method you don’t use silicone, it’s used to seal the bottom of the rubber membrane to the bottom flange.
Great article!
We’re just now at the point of moving to the mud floor and curb portion of the project. I had elected to install 1/2″ Hardibacker for the walls and also the floor (over thick plywood subfloor) for added regidity. The walls have been scratch coated with thinset to allow for better tile adhesion (Hb sucks up water pronto!).
Now, what I am thinking on doing is to: build a straight narrow curb out of poured concrete with rebar. I’d also ‘pin’ it to the floor and end walls. I don’t see that idea used very often though — is this a workable idea? I’m also in no rush so I can wait a week+ for the concrete to “cure”.
With the curb in I then plan on presloping the pan with your mud formula and cover both with Kerdi membrane. So, shall I treat the Hardibacker floor topper as concrete and just use thinset under the mud mortar — or is there a better way of doing it in this case?
Afterwards I’d like to paint a thick liquid membrane (like AquaDefense) on the walls, niches, BetterBench and then down onto the Kerdi floor membrane (which will wrap up the wall a few inches).
Am I on the right track
Hey Wayne,
Treat the backer on the floor as a cement floor and use thinset. Your plan sounds fine, except I wouldn’t pin the curb to both the floors and walls, I’d just attach it to the floor.
Thanks Roger.
Shall I let the thinset dry first, or plop the mortar onto the Hardibacker while the thinset underneath is still wet?
And, please explain further on not mechanically attaching to both the floor and the walls. I would think that there would have to be some continuity in making sure everything is sound and sealed — as in the cement board ..no movement, etc. Or would just the concrete adhering to the walls be good enough? (btw, the curb will be poured on the plywood subfloor, just outside the Hb footprint)
Lay it in there while the thinset is wet.
First, you are using pure concrete. Concrete cracks. Concrete ALWAYS cracks. It is also brittle, as in it can not handle opposing forces well, which is why it cracks. If you tie it into both the floor and walls it will crack quickly – those different planes will move in different directions. If you are using pure concrete it doesn’t matter which you attach it to, walls or floor. It should be done with deck mud or wet mud, both of which have added sand to compensate for that movement. If you are over a wood substrate why are you using pure concrete for your curb? You’re doing it the hard way.
You’re creating potential problems where none exist.
Cracking: is this the main reason why folks don’t go with concrete? — although I have seen photos of finished concrete substrates (ie, curbs) and that got me thinking about it. It seemed like such an easy solution to having a nice straight curb that’d be ideal for accepting Kerdi membrane.
Ok, so I don’t wanna use 2×4’s and build up from there either.
But I do have some clean gray 2x4x8 patio pavers ..or are these too large by the time tile is applied?
I guess these could be used instead. For a thin profile I could glue them all on edge length together with thinset(?) and do the same with attaching them to the floor and walls? Again, perhaps pinning them to the floor for added support? btw, the Hardi walls extend out past the main shower compartment — just past the glass doors — so the curb would abut them.
“Ok, so I don’t wanna use 2×4′s and build up from there either. ”
Why?
Pavers over wood may cause problems as well, the wood is going to move, individual bricks may not stay bonded to it or together.
Pavers (bricks) are used for curbs over concrete, wood (2×4’s) are used for curbs over a wooden substrate. If you have a wooden substrate you should use wood with backer over it. If you are using kerdi you can cover anything you use with kerdi.
I don’t understand the problem. You can, of course, build it however and with whatever you want, but you are using materials which are not well-suited to one another for, from what I can determine, absolutely no benefit. Is there a specific aspect of your curb which is not suited to using the correct material? What problem are you trying to solve by using different materials? Tell me what you are trying to do and I’ll try to help.
I just noticed you have backerboard on the floor as well. Nevermind.
You can use the pavers, they will stay bonded just fine. They are not too high or thick when covered with kerdi then tile. They work fine. Sorry, I’m stuck in the question answering vortex again and am getting different people’s projects mixed up.
ok ..so wood on wood, masonry on masonry ..not stable with mixing the two
POI — would floor leveling compound (ie, Planipatch) then be considered a cement base for a masonry curb?
Reason I ask is that if we go to a slightly larger shower stall depth (back wall to shower door, as my wife is rethinking) then we are just onto plywood subfloor with the curb ..unless I finish it with floor leveling compound (like Planipatch) which I planned to do anyway for new flooring. In that case would the Planipatch be considered cement > therefore I can use a masonry curb? or.. simply cut a strip of Hbacker to add on to the edge?
Hah ..perhaps I should have nixed the the Hbacker on the floor and just left it as plywood and built a conventional wire mesh over poly instead
Ultimately, I don’t want this shower project to fail — ever. Too many anecdotal examples shared online with punky wood curbs. Hence, I will try to mitigate any unforseen problems by locking in a (masonry) pan area with Kerdi, then perhaps reinforce it with the AquaDefence liquid, if there’s any left from doing the walls.
If it is cement board or a cement-based product (like planipatch) then a masonry product will work fine.
Roger,
During demo of my shower because it was leaking and found it to be a perfect example straight out of your book of jackassery I found that the contrator along with many other things never did any sort of pre sloap underneath the lower of a clamp style drain untop of the concrete slab. I see your diagram shows the presloap underneath the lower drain. I’m planning to do the remodel with a liquid membrane so based off my reading of your sight I wouldn’t need to do a pre sloap. My question is can i use the original drain lower and build build my deck mud sloap from inbetween the lower and upper drain at a 1/4″ per foot to the backerboards and than apply the membrane and seal to the top of the upper drain and tile over that? Any help you could provide would be greatly appreciated.
Hey Adam,
You can use the original drain if you use the divot method. It’s what you are describing except you need to raise the level of the mudbed so the tile will sit flush with the top of the drain. It’s just a single slope but around the drain it dips down to the level of between the upper and lower flange.
Roger,
I greatly appreciate your response! I went ahead and purchased your manual… had already intended to anyway and found the divot method. Kinda what I had in mind. If i decided to go with the topical drain, I assume I’d have to chip out the old. When installing the new drain what would I fill around it with?
I uploaded a few pictures under “Adam’s Shower Project” that I have a couple of questions about as well. My apologies I didn’t get the complete removal to show the extent of “not giving a :censored:” displayed by whomever inst. the shower. You can see I had to remove that bottom 1.5′ of sheet rock (by remove I mean clean up). I plan to repaint the faces of both these walls (tiling is also an option). Problem is the metal corner wraps around the wall and will sit over the face of the backerboard I’m getting ready to hang. Not to mention patching in the lower portion should be a treat getting a straight line. I’m not opposed to taking the sheet rock down on the face and installing new corners to the adjacent walls, just not sure how to tie into the shower backer board. What would you do here?
In reading your manual I noticed (jumped off the page and slapped me) the part about never using pressure treated lumber. Well, apparently Georgia code calls for pressure treated when laid on the slab. So the shower is lower framed in PT… do I need to remove and swap with KD?
Fill around the drain pipe with just concrete. The PT wood is fine in the wall cavity itself, but you need to use bricks for your curb – not lumber. You can cut that metal edge off above where you’re replacing the wall and replace it with a plastic corner bead. Redgard can be painted right over it.
Hi Roger,
I am putting “True Comfort” electric flooring under my shower stall and wanted to have entrance without a threshold. I was wondering whether having a heated floor would mean that I could not have to have slope. My thinking is that the drain will take the direct hitting water and the heated floor will result in evaporation of the splash. I have put two exhaust fans in the room to help exhaust the bathroom and adjoining sauna. Thanks for any advice. D.
Hey Darryl,
There is no installation method which would allow a shower floor which is not sloped. You absolutely still need a slope. You can have a curbless shower, but the floor will still need the minimum slope to the drain.
I had rotted studs/floor plate in the shower that were repaired by a contractor, and he put nails that face to the shower on the brace supports for the studs as well as the fire block. i’m guessing this is bad, as they are where the liner will go. what is the best way to correct this for the pan liner? is there something i can do to the nails(other than removing, there are a lot and are holding the boards in), or should i install drywall first and then my backerboard over the drywall? or is there a better way to proceed?
photobucket pic of issue: http://i12.photobucket.com/albums/a201/mila0504/DSCN0594_zpsf3de50c6.jpg
Hi Michelle,
There isn’t any problem with those nails at all. Just pound the faces flat so they are flush with the wood and install your membrane as usual. The only time it’s an issue is when they install nails THROUGH the liner, to hold it up. Don’t put drywall in there either – that’s bad.
Hi Roger, I’m using Hardibacker 500 and man is that stuff absorbent! I finally learned I had to spray the wall several times before trying to apply the thinset and Kerdi. Last night I was trying to finish the curb and I wasn’t able to get good adhesion no matter what I tried. The Kerdi was lifting off at the horizontal to vertical transitions. It seemed like the Kerdi was resisting being bent just enough to cause a problem.
Do you have any tricks for keeping the Kerdi adhered to the curb? And for that matter everywhere? I’m thinking of adding some 333 to my Laticrete 317 Thinset. Thanks, Alan
Hey Alan,
Mix a bit more water into your thinset. If it’s a little runny it’ll stick a lot better. It’s also easier if you crease the kerdi before folding it over the curb. The 317 will stick just fine if you get the consistency correct.
Roger,
Great information. I have a question about the shower curb. I’m building mine using bricks and fortified thinset. Last night I mixed the thinset and built the three brick high ‘brick’ wall. I think my next step is to cover the bricks with the ‘U’ shaped wire mesh? Does the wire just sit right against the bricks or should there be some space between it and the bricks for the ‘fat’ mud to get between? How thick should this mud layer be on the top and sides?
Thanks for your help!
Ken
Hey Ken,
If you’re using the traditional method your next step is to place your liner over the curb, then the lath right down over the top of the liner wrapping the curb. If you are using any type of topical method (kerdi, liquid, etc.) the you can go right over the bricks with it without worrying about the lath and wet mud. I normally do about 1/2″ thick for the wet mud all the way around the curb.
Hi Roger, help!
I started building a a two layer shower floor when I realized I should have used Kerdi. So I bought your Kerdi shower manual last night and now am worried about the drain.
Here’s where I’m at. I installed a traditional 3 piece drain on my wood subfloor. Then built a pre slope 3/4″ at the drain and 1-1/2″ at the walls. You taught me well.
How do I install the Kerdi drain now? The opening in the cement is about 6-1/2″. The top of the drain pipe is about 2-1/2″ below the pre slope. I saw there’s a Kerdi adapter but it looks like the finished drain would be way too tall.
Should I get one of those cool saws you have and cut out the 3 piece drain? Would I have enough drain pipe left for that?
Thanks for your advice! Alan
Hey Alan,
Yup, an inside pipe cutter to remove the current drain, then install the kerdi drain. 2 1/2″ is right where it needs to be to have 3/4 inches beneath the center of the drain. You can always lower the drain a bit to get where you need, or add a coupling to raise the pipe. Either will work if needed.
Roger, picked up some 317 today to install the Kerdi. I was also planning to buy some 333 Latex for installing the tile but the guy at the will call counter said he didn’t think I needed it.
Can I just use unmodified 317 to install the tile? My wife is leaning towards Travertine but I’m trying to talk her into something like Travertine floor (for grip) but porcelain or marble walls.
Thoughts? Alan
Yes, the 317 can be used for the tile. I use it all the time. The type of tile is purely a personal choice, gonna have to argue that one out with your wife.
Sorry.
How do you put the pan liner around an outside corner….. as in the outside corner of a bench seat… and seal the outside bottom corner. Will the Dam Corners work by using them backwards? I have to make a cut around that corner to have the pan liner lay flat on the floor. Do you have a suggestion on the best way to make that cut as well?
Hi Kathie,
Yes, the backwards dam corners are the way to go. All the other folds are dependent on the construction. The best way to explain it is to cut and fold it like you’re wrapping a birthday present.