Since I’m just a tile guy I”m not usually up on all the new technological crap that has nothing to do with tile, like online video or the ‘SlapChop’.  I’ve decided that since I spend most of my days in other people’s showers that I should get out more and learn something else.

So naturally, since I own kitchen knives, I decided to make a video about a tile subject. So here is my first video, sans sound because in audio I sound like a drunk leprechaun, for my readers. Umm – that’s you.

And since I actually have a day job and bills to pay all you get is a time-lapse photography of the creation of a mud deck for a tiled shower floor. But I’m gonna call it a tile video ’cause Google loves that shit.

If you’re old-school like me you can actually read the steps involved in this process starting with ‘How to Create a Shower Floor – Part 1′ wherein I will dazzle you with bad humor, lousy metaphors, and horrible photography. Oh, and a load of information on how to properly fabricate a shower floor for tile. But I know you just read my blog for the bad humor.

If you think my photography skills suck – wait’ll you see this. I’m absolutely certain the damn thing has already started playing even though I told it not to. Computers don’t listen to me. You can use the controls beneath the movie to start, stop, or FF, REW, all the old-school VCR stuff.

Feel free to leave a comment below. You know, something like ‘Hey dumbass, you shoulda bought a SlapChop instead!’ If you want more videos just let me know. Maybe one day, with enough practice, I’ll be able to make one that doesn’t look like a three-year-old did it. Enjoy.

Well now we’re ready to waterproof your curb. If you have reached this post before reading the previous two, start with How to build a shower floor from the beginning.  Now that you’re ready to get the curb cut and waterproofed lets get it done.

And yes, I know my pictures suck – I’m a tile guy for cryin’ out loud, not a professional photographer. Until you try to balance a liner, a razor knife, a margin trowel, and a camera while trying to take a photo don’t give me any crap about it. Oh, and you can click on any of the images for a full-size version – partake in the full glory of how much my photography sucks.

We need to start by finding the inside lower corner of your shower pan and making certain that the liner is pressed firmly against it. Then follow it up the corner of the curb and wall to the top inside corner of your curb. This is the spot at which you will start the cut in your liner.

Cutting a liner for a curb when shower walls will be backerboard Click to Enlarge

Deciding in which direction to make your cut depends upon how you plan to waterproof the walls. If you are simply using a cementious backerboard on your walls with a moisture barrier behind it you want to cut from that point straight up. Or, more precisely, cut your liner so that when it is placed flat against the studs the cut will go straight up from that point.

If, however, you are using a topical waterproofing membrane (that’s just fancy-ass, pinkie in the air talk for waterproofing that goes right behind the tile) I cut it a bit differently. Start from the inside top corner of the curb and cut straight out to the outside corner of the curb.

Cutting a liner for curb when using a topical membrane

The reason for this is simple – to me anyway – if you are using a cement backerboard or any type of substrate where moisture will get behind your wall, you want to have as much of a liner at the ends of the curbs as possible to run up the wall. With a topical membrane such as Schluter Kerdi or a liquid such as Redgard you don’t have to worry about that. By the time any water behind the tile gets to the bottom of your waterproofing it should be well below your curb – provided you’ve installed it correctly.

On the inside corner of the curb you should install a ‘dam corner’. These are pre-formed outside corners which are glued to the liner to cover the spot where you’ve made the cut. I do not have a picture of these because I don’t use them, I’m a hypocritical bastard like that. But you should. (Use the dam corners, not be a hypocritical bastard.)

When you do glue your dam corners in you need to make sure you use the correct type of glue. Just like drain pipes – pvc glue for pvc liners and cpe glue for cpe liners. The glue WILL NOT work the other way around. Really, don’t try it, it’s an expensive lesson. Take my word for it.

The liner gets wrapped over the top of the curb

Now that you have the ends of the curb cut we need to move on to preparing the curb for tile. Take your 2 x 4 that you used to level your pre-slope perimeter (you did that, right?) and place it in the inside corner of your liner against the curb and the floor. This ensures that the liner lies completely against the floor and the curb without air pockets or empty space beneath it. Then nail the OUTSIDE of your liner to the curb – only the outside, never the inside.

Please note: these photos were taken after my final mud bed was in place. I installed the curb last on this particular project. You can do it before or after your final mud bed is fabricated. Dealer’s choice.

Nailed only on the outside of the curb

To hold the liner in place over the top of the curb you need some metal lathe. Provided your curb consists of three 2 x 4′s your lathe needs to be cut into strips sized to fit over your curb from the floor on the outside to the inside bottom corner of your shower. Bend the lathe into a ‘U’ shape (length-wise) and place it over the top of your liner over your curb. Something else I do not have a photo of. Just because I’ve never taken one, not because I do it differently.

You only need to nail the liner on the outside if you have a wooden curb. If your shower is on a concrete subfloor you used bricks for your curb – right? Pay attention, if you fail the quiz later you owe me a beer Pepsi.

I have one more photo for this post and this is it. Isn’t that spectacular? It’s just to show you how I do the ends of the curb when using Kerdi on the walls. “But why don’t you use Kerdi on the floor too?” Glad you asked. It’s a very technical answer and requires you pay attention to every part of it or you may get lost in all the details. Ready? Because some people don’t wanna pay over 100 dollars for a shower drain. Whaddya gonna do?

Shower pan liner on the end of the curb.

Couple of things I’d like to point out about that last photo before you go bustin’ my chops too hard. First, the excess liner is not yet cut out. I cut it straight down the edge of the drywall there and everything gets tucked straight back into the wall. Secondly, yes, I put a nail through the liner. A foot above the curb. You can light it on fire that high if you choose to do so. (I wouldn’t recommend that, though. And no, I don’t want to talk type about it.)

Now we have to water test your pan to make sure it does not leak. Note: most cities and counties REQUIRE this to be done – don’t skip it. The test simply ensures that all your hard work is indeed correct and your pan does not leak. That’s it.

You need to plug the drain (or you’ll be there all night trying to get enough water into it) which you can do with either a $75 specialty plug, or a water balloon. You pick. You need to make absolutely sure that (and I’m assuming you chose the balloon option) the balloon is pushed far enough down into the drain to block the weep holes as well.  If they are not it will let you know that your weep holes work correctly. Unfortunately it does nothing to reassure you about the liner. If you look carefully into the drain you should be able to see the holes for the weep holes, get below them with your plug.

Then just fill ‘er up. All the way up to just a hair below the top of the curb. (take the 2 x 4 out of it first if it’s still in there) and leave it set for 24 hours. After the 24 hours have elapsed and you are reasonably recovered from your recently induced hangover, check to make sure the level of the water has not gone down. If it hasn’t you are ready to go.

Now if we could just get that elf guy off his ass to write the next post you will learn how to fabricate your final mud bed and tile that sucker. Hang tight, we’ll go get him. Check back real soon, y’all. And as always, if you have any questions at all please feel free to use the comment section below.

Properly built shower

Curb and Pre-slope

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