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
This is definitely the best site I’ve found so far. Thank you for all of the detailed info.
I’m doing a custom shower base in my basement. On a concrete floor, I saw that I need to use regular thinset first (before the pre-slope mud). Do I just trowel a single layer like I would do for laying tile? Also, do I need to use metal lathe? How about on the brick curb?
Hi Sue,
Yes, just like laying the tile. You want to bond the deck mud to the concrete. No, you don’t need metal lath. You may or may not need it over the curb, if you are using traditional waterproofing on your shower floor then yes, you do. The liner goes over the bricks and the lath is folded over it to hold it in place, then wet mud is used to form your curb.
Question about building the curb out of bricks,
Can I used modified thinset to attach the bricks to the slab AND between each brick AND for a second row of bricks on top of the first or should I use brick mortar for that?
Is a gap (lets say 1/8) between each brick required or can I pack them tightly together buttering between them with thinset and cutting the last brick to size?
Finally when I’m applying the thinset to the slab/bricks, do I trowel it with my 1/4 x 1/4 square trowel just like applying tile or do you just smear a small amount with the flat side of the trowel?
Thanks in advance for your advice!
Hi Fernando,
You can use modified thinset for all of it. Yes, you can squeeze them as tightly as you want to. Trowel it as normal and burn it into the surface of the brick (skim-coat the brick to fill the pores).
Roger:
We are removing a 30 year old fiberglass tub from our second floor bathroom. We want to convert it to a shower only bath. The drain is less than 4 inches from the wall. Will we be able to keep the drain there and still have a successful drain slope or must we center the drain? Due to the bathroom’s original design, we will have to make the shower the size of the tub so it will be a long rectangle and not a small even-ish square.
My husband hates plumbing (due to traumatic events on his first attempt to work with it: along an 50 foot brick wall, he drills a hole directly into a water line…the only water line in the entire wall) but I am not intimidated by it. I am 99.99% sure if we can see it done on a video, we will be able to do it successfully.
Thanks for all you do. It appears you help a lot of people.
Dianne
Roger:
We watched the Laticrete video and read your review. We think that is the way we are going to go.
Dianne
Hi Dianne,
You can leave it if you want, but you’ll have a very steep slope from the drain to the closest wall. It’s normally better to move it. Moving the drain doesn’t involve any water lines at all, if that helps.
Hi Roger,
I took a break from my shower project to rip out my grass and convert to desert landscape. Back working on the shower again and my last questions were regarding the width of my wallboard. As I’m installing it, my bottom corners are either too tight or don’t line up straight after sanding them down. I think this is due to the thickness of my pan. Will I be able to install tile without having a wavy wall?
Hi Rick,
If you mean the thickness of your pan liner then you should have either shimmed the backer out above the pan or chiseled out about 1/8″ of the studs in order to tuck the liner into them. You can get the wall tile flat by just adding a bit more thinset or a slightly larger trowel, this will allow you to adjust the tile in or out a bit to get it flat.
No I mean the gap between the pan and bottom of the wallboard is not level if that makes sense. Then I have to cut the sides of the wallboard to make them flush in the corners to screw them in. I can fill in the bottom and sides with fiber tape and thin set and regard. I think I can fix tile issues with more or less thin set. Do you agree?
Yes.
You indicate that it is best to have a “level” line around the top of the deck mud in order to avoid nasty tile cuts on the wall. This makes sense, but for a right or left hand drain that is 10 inches drain center to stud wall (resulting in about 7 inches from drain edge to wall) this would result in a slope of greater than 1″ per foot at that spot. Of course, the slope from drain edge to opposite end of shower would still be 1/4″ per foot.
Do I “have it right”? or am I missing something
Hi Curt,
You are correct. It is entirely up to you which to do in that situation, level bottom row or cut bottom row.
great instructions. thank you.
I’ve got to build a concrete block bench on my concrete floor. Do I build the bench first, then do everything for the shower floor, or do the shower floor first, then build the bench?
Hi Dale,
It depends on if you’re using a topical waterproofing for the shower floor or not. If so build the bench first then use the topical waterproofing over the face of it. If not then build and waterproof your shower floor first then build the bench inside of it.
Re: Mud base mixes.
Mortar mix? or Sand and topping mix plus sand, and also stucco base coat for the curb! Thats a lot of product(s) for a 12 sf. base. It’s all a little confusing and depends who you ask. This other site shows mortar mix used for both layers: http://www.icreatables.com/tile/shower-pan-mortar.html Why would this not work well for slope top and curb?
Mixing S&T mix with more sand seems a little soft for the application. Using a dryer mix like this seems like would make it more prone to cracking. It would suck if it fails. I am a little hesitant. Few of us are masons. Many are problem solvers who spend a lot of time thinking and could be done already!
Hi Todd,
Because that is not the proper way to do it. Lot of products or not the sand and cement is the proper way to do it. Sand, cement and lime are the proper way to do the curb. Stucco mix is something I recommend because many do not have access to masonry lime.
Straight mortar will crack – A LOT. A layer of mortar over wire is called a jersey mud job – look it up. It doesn’t work, and it damn sure doesn’t work for shower floors. The sand and cement mix has a psi well above 4500lbs/sqin, much more than needed. And the added sand allows the tile installation to be separated from the movement of the structure.
“Many are problem solvers” – Yes, I am. Every day of the week. But being a ‘problem solver’ that finds and easier way to do it and being a problem solver who finds and easier way to do it PROPERLY are two completely different things. So while the first problem solver may finish the shower more quickly, as you’ve alluded to, in twenty years my shower will still be standing whereas the improperly built shower will have to be rebuilt 4 or 5 times.
But you can do it that way if you want – it’s your shower.
Dear Floor Elf,
We are first time bathroom remodelers and are grateful for your information. We have somehow found our way to a 3 ft x 8 1/2 ft huge shower. The drain is off-center because of the smaller original shower. As we understand, there should be a one-quarter inch slope per foot. From the farthest end, it seems the slope should be a total of about 1 3/4 inches. Did we figure that correctly and how the heck do we do that? It seems so much so our goofy question is: even with the longer distance do we still figure 1/4 inch per foot? I hope I’ve asked this correctly–my husband fell asleep in the chair and isn’t answering my questions so I might have mis-conveyed our quandary? Thanks so much.
Hi Mary,
It needs to be 1/4″ / foot from the drain to the farthest corner. For instance, if your drain is 5 feet from the furthest corner then your slope needs to rise 1 1/4″. The slope will vary unless your drain is in the center of a square shower. Provided it is at least 1/4″ per foot you’re fine. Find the rise you need and draw a level line all the way around the perimeter. The perimeter should be level, your slope will be 1/4″ per foot at minimum from that line down to the drain in the entire shower.
Hi Roger.
I’m a DIY’r and purchasing all the goodies to do my shower.
Question: not to sound dumb. You refer to thinset in a couple places. Under the preslope and used to put down the concrete brick for the curb. In both of these places are referring to the thinset that is purchased in the tile department or mortar “type n or type s” that’s purchased in the construction department? Thanks much.
Hi Wes,
Thinset from the tile department. It’s not dumb to ask a question before diving in and screwing something up.
Guess I forgot to mention I plan on doing a niche anyway
and looks like topical is the way to go thanks !
I got your traditional manual (floor and walls) have done the traditional shower base and am finding out it is eather Impossible or to hard to put in a niche so got your topical manual looks like I’m set with most everything but how to seal the bottem do I just use silicone at the bottem of the concrete bord to the shower base liner ?
I just insalled a shower stall in my basment and used bricks for the shower curb. I created my own pan and used the membrane. I currently have it that the membrane is going completely over top of the bricks. I feel that this isn’t correct because there would be no place to attach the tile due to the membrane. Read some place about cutting it off and glueing it. Any help on this matter would be greatly appreciated.
Hi Matt,
That search box up there works really, really well.
Creating a curb
We have a shower stall. The floor of the shower is showing what is under it. To fix it I want to put over this floor little square ceramic tile. The space is 3 by 3 feet. Do I have to put a layer of something under these small tiles? I do not want the water to leak under the tiles.
Thanks for your advice.
I know what I want, but (and a big one) do not know how to do it.
Hi Margarita,
I have no idea what the floor of your shower is made of. If it is acrylic then you can not install tiles to it. You need to remove the base and create a shower floor in it’s place for the tile. If it is something different you’ll need to let me know what that is.
The shower is made of fiberglass. I want to send you a pic of what I have, but I do not know how to attach it to this message. I did it to your email to The Floor Elf but I have not received a reply. Maybe you did not get it. I am not very good at the pc.
Thanks for your patience.
Margarita
There is no way to attach photos to a comment, it’s in the works. I have your email, just haven’t answered it yet. I respond here before I respond anywhere else, email included. Day job and all, limited time and I get a LOT of questions.
I’ll answer your email shortly.
I’m converting a tub/shower to shower only with a right hand drain. I put in my pre slope and I can tell its sloped correct except for one far corner has a slight dip. Do I need to fill in this dip or can I move forward without stating over? Also, can durorock be installed after final pan?
Hi Rick,
It depends on how large the dip is. If it will still allow water to drain fine I would leave it. Yes, backer can be installed after the mud.
I just poured my pan and realized I forgot to put pebbles around the drain to protect the weep holes. should I rip it out or if I regard the pan will I be ok?
Hi Rick,
You can scrape out around the drain, put your pebbles in there, then install more deck mud around the drain. The weep holes NEED to be open. Redgard won’t work with weep holes beneath it.
Thanks for the help so far Roger. One more question. Now that I’ve poured the pan there is only a 1.5 inch from the top of the pan to to the top of my wrapped curb. It slopes down to 2.5 in the middle and 3.5 at the other end where the right hand drain is. Should I add another 2×4 to the top of my already wrapped curb so there is more space to tile the inside of my curb? I lied, one more question. Should I Redgard the pan prior to tile?
You out there Roger? Haven’t heard back from you? Maybe your on the beach somewhere.
Unfortunately no beach. Day job instead.
Damnit.
Entirely up to you. 1.5″ is fine, or you can put more if you want. No, do not use redgard if you already have the membrane under the floor.
Roger,
I read your waterproofing manual but still confused on how to seal my joints on my cement board. Do I regard then fiber tape and then regard again at all seams? Or do I use fiber tape and mortar and then regard? Thanks.
Fiber tape and mortar, let that cure, then redgard. The tape and mortar solidifies it, the redgard waterproofs everything.
Me again Roger,
My wall opening is 37″ wide and 78 1/4 high. Wonder board is 3×5. Either way I install it I’ll be either an inch short on the side if installed vertically or 6 inches short on the top if I stack two pieces. I could buy a 4×8 Durock and cut to fit but pretty heavy. What to you suggest?
Hi me again,
I would cut one piece in half and use it for the first sheet at the bottom, stack it and have a 2′ piece at the top.
That still wouldn’t give me the width I need on the side which is 37 inches. That extra inch it going to be outside of the shower curb but kind of hard to fill that space with joint compound. I think I’ll try a full sheet of Durock and cut it in half to relieve some of the weight of the full sheet. Do you agree?
I meant cut it in half the long way, so you have a 1’6″ piece by 5′ piece at the bottom (cut down to 37″), cut the rest of them to 37″ x 3″ and stack them. Or you could cut a full sheet down in half as you mention.
Hey Roger,
I have a question about the thinset slurry you said to use when working over concrete. I am actually using deck mud to level out a concrete floor in my kitchen that I want to tile w/18X18’s and I don’t want corners sticking up. I don’t want to use self leveling mud because I am actually not making it level, just as flat as possible. (If I make it level the floor will be too high on one end.) I tried to put the mud right over the old concrete but a couple of days later it started loosening up. Today I found your site and learned that deck mud won’t stick to concrete. So, do I install the deck mud while the slurry is still wet? Or should I be using some kind of additive in this situation (Acryl 60)? Also, how thin can I go with deck mud? Lastly, some of the floor seems to be sticking (even when I beat it with a hammer at a slight angle). Do I need to remove all of my mistake (with a cold chisel) or just the parts that aren’t holding? Thanks for your help.
Thanks
Hi David,
You install it while the thinset is wet. Absolute minimum thickness of deck mud is about 1/2″. If you need thinner than that then a concrete-based floor patch would be a better option. You need to remove the old stuff, it may not be loose now, but it will be.
Roger,
I fired my contractor and am left with a half finished tub to shower stall conversion. I thought the shower stall was ready for tile work until reading your how-to blog. My concern is
the contractor built the curb with three 2×4’s on the concrete slab. The 2×4 in contact with the slab is pressure treated. The other 2 are not. Do I need to tear the curb out and build one with brick? If so how can I minimize damage to the mud shower pan during this process?
Hi Richard,
Yes, it should be removed. I can’t tell you how to do it without damage without knowing how your shower floor was waterproofed and whether or not the pan is tiled already.
I used your formula with topper/mix and sand for the base. It has been 3 days, its not cured yet but I can rub the surface and get sand grit off the top. I cant image this surface being good enough to bond to. I planned to spread thin set over this, then kerdi for water proofing. Any suggestions? I now wish I would of used straight cement.
Hi Tom,
It is cured. What makes you think it is not cured – because it’s sandy? If it were not cured it would not be sandy. Yes, you can skim over it with thinset, let it cure, then install your kerdi.
Just FYI – had you used straight cement you would be replacing it within a year. The reason you use deck mud and the reason it has so much sand is to compensate for structural movement through the deck without transferring that movement through to the tile. Deck mud will dissipate the movement and it will never reach your waterproofing or tile. Cement will crack, end up cracking your grout lines and/or tile, and possibly compromising your waterproofing. Yes, straight cement is easier, if it worked I would use it too. It does not, there are reasons we use the methods we do.
Hi Roger,
Just bought your book on creating a shower floor with topical products. Very informative and helpful. Glad to know there’s a drain for topical membranes even if it is pricey. I’ve been wondering about that. One question, can I use Denshield on the walls instead of Hardibacker or will this affect my transitions from the walls to the pan in the corners? I noticed that you only used concrete based backer boards in your book.
Hi Kenny,
You can, but you’ll need to keep the densshield out of the mud, paint the bottom edge of it and silicone between the floor mud and the wall.
Hi,
Great site! I’m building a shower pan in my new construction house. The preslope is in, but I just realized two big issues. 1. The plumber installed the drain (bottom part) flush with the subfloor. The flange does not sit on top of the subfloor. Because my body works faster than my brain, I didn’t realize this was an issue until (issue 2) my preslope at the drain was only 1/4″. So, the bottom flange of the drain is 1/4″ below my preslope at the drain.
My questions are – should the drain (the bottom part) be attached to the subfloor… Or should it be raised to accommodate the preslope thickness?Second, can I add more deck mud to the existing dried deck mud… Or should I use thin set on top of the preslope to make it thicker?
Thanks for your help!!!
Eric
Hi Eric,
Yes, the flange should be raised to a proper height. If you need more than about 1/8″ you need to do it with deck mud, not thinset. But you need to put thinset on the preslope to bond the new deck mud to it.
Thanks Roger. Looks like I have call the plumber back out to fix this… again! First, no pre-slope, then they nailed the membrane below the curb, now the drain… good thing I found this website. Going to finish it the right on my own (with the help from the Floor Elf of course).
Hi Roger,
Great site! I have a question about the single-layer shower floor which can then be coated with RedGard. Is there a reason you do the 2 stage method over the single stage method with Redgard?
Thanks in advance,
Kenny
Hi Kenny,
It just depends on the method I’m using. I don’t necessarily do one over the other, it’s a combination of what is needed in a specific construction and what the client is paying for.
I have looked through your blogs and your replies to people. I can’t find any reason not to replace the rotted out floor in my mobile home shower and build a mud slope, install backerboard on the walls, apply a liquid membrane, then tile it. What was in there was a small shower with very thin wallboard, like masonite, which is rotted up to about two feet. It had a cracked, leaky plastic shower pan placed on particle board. There’s no trace of any moisture barrier. It was only caulked. I find the installation horribly poor and don’t want to buy a replacement pan and shower surrounds. I want to do the job myself.
I had planned to reinforce the floor joists with sister boards and cross supports to make it strong and level. I want to use 3/4 exterior plywood for the new floor. I’ve downloaded your information pdfs and want to go ahead with the job.
Do you agree that it should be fine to build a shower, using your instructions, for my mobile home? I ask because I haven’t found anyone else doing this.
Thank you,
Alan
Hi Alan,
Absolutely no reason at all not to do it. Provided you can shore up the framing to support a proper installation there will be no problem with it at all.
We have a 32×36″ concrete shower in our basement that has been painted with blue concrete pool paint. It is not smooth and looks unfinished and rough. I would like to finish it. I am not sure how to go about it. Someone said just tile over the existing surface but that seems unwise since the paint has already chipped on the floor. The corners are not clean angles. The shower operates fine with water draining into the drain as it should. If we apply backer board, how do we attach it to the walls so that it doesn’t decrease the size of the shower too much and is straight and level?
update. The size is 36×40 and the walls are made of concrete brick and then painted. It looks as if the floor has some sort of liner at the point where the walls and floor meet which I can see the faint outline of through the thick pool paint layer. Would it be easiest to just tear out the shower and start over? I hope not but am starting to wonder.
Hi Kristina,
You can not install backer over your concrete walls. You need to scarify the existing finish, then use a waterproofing liquid or fabric over the concrete, then install your tile directly to it.
Hello Mr High Elf of the Floor forest.
I sent a first message but I guess it got erased automatically (because links).
I am building a new shower, but I want to use a linear drain, the type that drops into a drain for topical membrane (not the laticrete kind, because I am not rich
The shower is 36″ x 60″ and the drain would be in the center, along the short axis.
I was wondering how to do a preslope and final slope in that situation. The instructions that come with the drain are garbage, with no slope install at all, and I want to do it properly. I made a few drawings that would make all of this clearer but I’m not sure how to send them – they are upladed to imgur (SparklesAndRobots), but I think putting the link here will block my message again as spam. Any other way to send you links?
In any case my idea is to make a gutter where the drain will go, so in the center of the shower along the short axis.
Preslope: a 1/4″/foot slope in the gutter (starting with 3/4″ of mud under the drain). On each side of the gutter (the drain is in the center of the shower) make a ‘strait slope’, with the lowest point along the gutter (and a tad higher then the highest point in the gutter), and the highest point parralel to the gutter at the curb (still following a 1/4″/foot slope)
Then put membrane + top part of drain.
For the final slope, I need to level the gutter so that I an install the drain on a flat surface – so I’d add only 1/4″ of mud to the highest point of the preslope, but 3/4″ in the center, to have my drain (and all of the gutter) at a height of 1 1/2″ total. I’d add an even 3/4″ on the two ‘strait slopes’ to keep the same slope as the preslope. This all works out that the drain, once installed, should be about 1/8″ below the neighbouring tiles.
It’d be so much clearer with the drawings!!!
But if you can figure out what I am saying, please let me know if you think that would work out. THANKS A BIGILLIONS!!!
Hi Mimi,
I’m confused, you said you want to use a linear drain for topical waterproofing, but you’re describing the method used for a traditional linear drain – which is it? If it is a topical drain (I understand it ties into the regular drain base) the weep holes are not utilized, you only need one slope, not a bottom then a top, and you don’t need a membrane. If the membrane you are speaking of it a topical membrane then the tile is bonded directly to it, you don’t need another mud bed over it. What specific drain do you have? Do you have a link to it? You can place one link, any more than that and the spam nazis blow it up.
I just found your links. Your plan is fine depth-wise and all that. It is not a topical drain.
And for some reason (because they don’t know any better) the literature on their drain on the site does not include a pre-slope, so you are already doing better than them. 
Thanks a bunch about pulling my mail from the spam and checking links (I assume), and sorry about getting garbled about topical vs traditionnal. It’s a lot of info to process!
Your site is wonderful, I don’t know if I would have had the courage to jump into a project like this without proper guidance, and I found pretty much everything I needed (and much more) on this site. It is very generous and selfless of you to share your knowledge like that.
Hugs from Canada!
Roger,
I just bought your Kerdi shower manual, and was wondering where you got the round bubble level for setting the Kerdi drain. Is it a special “plumber’s drain level”, or can mere mortals possess such an item.
The Kerdi manual helped make me feel much better about the bathroom remodel I’m doing, so thank you kindly for that gem.
One other question: I read your article about SpectraLock, and was wondering if you recommend epoxy grout for tile showers and floors over sanded grout. I’d like to avoid sealing and cleaning grout every year, so if this stuff’s better, I’d like to go with it right off the bat.
Cheers,
Sean
Hi Sean,
That is called the Tavy tile puck, you can pick one up at Lowes or order one online. They are handy little items. I would definitely choose spectralock over regular sanded grout if given the choice, much better option.
What is your opinion on the prefabed kerdi shower floors/pans? Time saver or waste of money? Also it seems if you have to cut it in a way you don’t take the same amount of each side the first course of tile won’t be straight(like if you had to cut a 7’x7′ one down to 5’x4′). I guess in most cases it would only be an eighth or quarter of an inch… How do they figure we should handle that?
Hey Matt,
They are a huge time saver, I just don’t use them because they never fit the showers I build. If you only have to cut that much off you can just cut off one end and use a little extra thinset beneath one side to shim it level.