The Floor Elf

Series: How to Build a Traditional Shower Floor

This series covers building a traditionally waterproofed shower floor using a clamping drain and rubber liner. Each step builds on the previous one.

1. Building the curb and installing the pre-slope
   Creating the foundation that ensures water moves toward the drain — not into your framing.
2. Positioning and installing the shower liner
   Correct placement of the liner over the pre-slope and into the drain assembly.
3. Forming the liner around the curb and flood testing <-You are here
   Properly wrapping the curb and verifying the liner is watertight before moving forward.
4. Finishing the drain and forming the level perimeter
   Setting drain height and creating a consistent, level perimeter for the final mud bed.
5. Tying in wall waterproofing and finishing the mud bed
   Integrating the walls with the floor and completing the final sloped surface.
6. Building a shower floor – Video
   Time-lapse video of creating a shower floor

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.

[continue reading…]

Series: How to Build a Traditional Shower Floor

This series covers building a traditionally waterproofed shower floor using a clamping drain and rubber liner. Each step builds on the previous one.

1. Building the curb and installing the pre-slope
   Creating the foundation that ensures water moves toward the drain — not into your framing.
2. Positioning and installing the shower liner <-You are here
   Correct placement of the liner over the pre-slope and into the drain assembly.
3. Forming the liner around the curb and flood testing
   Properly wrapping the curb and verifying the liner is watertight before moving forward.
4. Finishing the drain and forming the level perimeter
   Setting drain height and creating a consistent, level perimeter for the final mud bed.
5. Tying in wall waterproofing and finishing the mud bed
   Integrating the walls with the floor and completing the final sloped surface.
6. Building a shower floor – Video
   Time-lapse video of creating a shower floor

Now that you have your curb built and your pre-slope done (if you haven’t done this yet check out How to create a shower floor, Part 1) you are ready to install your waterproof liner.

Purchasing a waterproof liner

When you order or buy your liner you need to get one large enough for your shower. The liner you get has to be at least one additional foot larger than each of your measurements. For instance, if your shower floor is three feet by five feet your liner needs to be four feet by six feet. This allows enough to run the liner up the wall behind your backerboard six inches each way. You also want to purchase two “outside” corners for your curb. These are pre-formed corner pieces to waterproof the ends of your curb after you cut the liner.

I usually order mine two feet larger in each direction. Six inches is the minimum. Specifications state that your liner must run up the wall at least three inches above your curb. So if your curb is three inches high your liner needs to run at least six inches up each wall. I usually go a foot above the curb – overbuilding your shower is rarely a bad thing.

[continue reading…]

Series: How to Build a Traditional Shower Floor

This series covers building a traditionally waterproofed shower floor using a clamping drain and rubber liner. Each step builds on the previous one.

1. Building the curb and installing the pre-slope <-You are here
   Creating the foundation that ensures water moves toward the drain — not into your framing.
2. Positioning and installing the shower liner
   Correct placement of the liner over the pre-slope and into the drain assembly.
3. Forming the liner around the curb and flood testing
   Properly wrapping the curb and verifying the liner is watertight before moving forward.
4. Finishing the drain and forming the level perimeter
   Setting drain height and creating a consistent, level perimeter for the final mud bed.
5. Tying in wall waterproofing and finishing the mud bed
   Integrating the walls with the floor and completing the final sloped surface.
6. Building a shower floor – Video
   Time-lapse video of creating a shower floor

This series covers building a traditionally waterproofed shower floor using a clamping drain and rubber liner. Each step builds on the previous one — skipping steps is how shower floors fail.

1. Building the curb and installing the pre-slope <-You are here
   Creating the foundation that ensures water moves toward the drain — not into your framing.
2. Positioning and installing the shower liner
   Correct placement of the liner over the pre-slope and into the drain assembly.
3. Forming the liner around the curb and flood testing
   Properly wrapping the curb and verifying the liner is watertight before moving forward.
4. Finishing the drain and forming the level perimeter
   Setting drain height and creating a consistent, level perimeter for the final mud bed.
5. Tying in wall waterproofing and finishing the mud bed
   Integrating the walls with the floor and completing the final sloped surface.

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.

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To create a shower floor from scratch we use what is commonly referred to as “dry pack mortar” or deck mud. Deck mud contains three ingredients: regular portland cement, sand, and water. That’s it. Don’t let anyone tell you that a latex additive or anything else is necessary. It is not. Properly mixing and installing deck mud will create a shower floor that will last for years.

The ratio is very important to achieve the correct consistency and stability. You want 5 parts sand to 1 part cement. Your ratio can vary from 4 to 6 : 1 but the 5 : 1 is what I use and find to be the easiest to work. You want just enough water to dampen the mixture. It’s not a lot. Too much water will cause your mud to shrink as it cures and compromise the stability of your base. You just want it damp – really.

The photo below shows the proper consistency of deck mud when you grab a handful and squeeze it.

The easiest and most convenient way to get your mixture correct is to buy the quikrete “sand and topping” mix which is sold at all the big home centers. This is already mixed at a 3 : 1 ratio. For a 60lb. bag you need only add 30lbs. of sand to it. This is how I mix mine – it’s convenient. The easiest way to mix it is with a regular shovel or garden hoe in a mixing box or regular wheelbarrow, although you can mix it with and in anything that works for you.

After it’s mixed it should just be damp. When you pick up a handful of it you should be able to squeeze it without water dripping from it. It should be able to hold it’s shape when you squeeze it, just like a snowball. [continue reading…]

A common misconception about tile and grout is that grout will somehow assist in stabilizing a tile installation. It does not. Unless you use epoxy grout it will add no significant structural elements at all.

So why should I use grout?

Grout is, structurally speaking typing, simply there to fill the spaces between tiles. That is an oversimplification, but it describes the grout’s function. More to the point, it is there to keep other things out of that space. Without grout the possibility of dirt, grime and all sorts of unruly, unwanted things may collect in the spaces between tiles. This may lead to not only unhealthy conditions, but also the chance of damaging your tile while trying to remove those things.

Does epoxy grout help stabilize tile?

If you’ve read any of my other posts regarding grout you have more than likely seen me state that epoxy is different. This subject is no exception.

Epoxy grout will actually add to the stability of your tile installation – to an extent. Epoxy will stabilize only the area between the tiles – the grout lines. It does not stabilize your tile enough to replace proper installation methods. This is not what epoxy grout is intended for.

A couple of reasons for using epoxy grout include the durability, ease of cleaning, and its ability to withstand staining. It is not intended as a product to make a sub-par installation correct. [continue reading…]

***RedGard is not paint.***
It does not waterproof by color, coverage, or the number of coats you apply. RedGard only works when it is applied at the manufacturer’s required thickness, over a proper substrate, with reinforcement at seams and changes of plane. A red wall does not mean a waterproof wall.

Elastomeric or liquid waterproofing membranes are one of the most convenient methods of waterproofing shower walls before installing tile. These membranes consist of products such as Custom Building Products’ Redgard and Laticrete’s Hydrobarrier and Hydroban and Mapei’s Aquadefense. I will refer to all the membranes as Redgard for the purposes of this post, but they all work nearly the same way.

These materials can be installed with a regular paint brush, paint roller, trowel, or even sprayed on. They are applied to your shower walls then tile is installed directly onto it. When I use these products I always use a cement-based backerboard as the wall substrate without a plastic vapor barrier. 

Your cement backerboard must be installed correctly WITHOUT A VAPOR BARRIER BEHIND IT! You do not want an additional barrier behind your backerboard if you are installing a topical waterproofing membrane over the front of it.

You HAVE to tape and mud the seams and any changes of plane (corners) as described in the post I linked to above. Just applying the fiberglass tape with Redgard over it is not sufficient. You need to install the fiberglass tape on all your seams and corners with thinset, let that cure, then paint the membrane over it.

It is imperative that you do not install plastic behind your walls since this would create two waterproof membranes with your substrate between them. Having two barriers this close together leaves open the chance of trapping moisture between them with no way for it to evaporate. This may lead to mold.You must also tape the backerboard seams with fiberglass mesh drywall tape. [continue reading…]

Installing cement backerboard is one of the more popular choices for a shower wall substrate. Cement backerboards include Hardiebacker, Durock, Fiberboard, wonderboard, and similar products. These materials bridge the gap between expense and effectiveness. When installed properly they will give you many, many years of durable shower construction.

The advantage of cement backerboards is that, while not waterproof, they are dimensionally stable when wet. That just means that when they get wet they do not swell up. Any swelling behind tile is a bad thing. It will lead to cracking grout, tile, and all sorts of bad things.

Waterproofing your studs

To install the backerboard you must have a vapor barrier between it and the wooden wall studs. While the backerboard will not swell when wet, your wall studs will. You must prevent any moisture from reaching them. The preferred material for a vapor barrier would be 4 mil or thicker plastic sheeting which can be purchased at places like Home Depot or any hardware store. You can also use tar paper or roofing paper, the thick black paper used under shingles. Although I personally do not use that, it is an acceptable barrier. [continue reading…]

Before installing tile on your floor you must make sure your floor is properly prepared.  A properly prepared floor does not have to be level. It must, however, be flat.

The only time the levelness (is that a word?) must be taken into consideration is when drainage is an issue, such as on a porch or in a shower. In those cases you must make sure your floor is not level – it has to be angled toward a drainage area.

If your floor will not be subjected to water regularly, such as a kitchen or bathroom floor, it does not necessarily have to be level. That does not mean you can have a 45 degree angle from your door to the cabinet (although I suppose you could if you wanted), it just means if your floor is not absolutely level it will not negatively affect your tile installation.

One of the things you must make sure of, among other things, is that your floor is flat. If it is not it will be difficult to set your tiles without what we call “lippage”. That’s a ridiculous word, isn’t it? Lippage simply describes the difference in the height of two adjacent tiles. If you have a tile that sticks up higher than the tile next to it you have lippage. You don’t want that. Starting with a flat floor helps prevent it.

When prepping your floor for tile trade your level for a straight edge. Don’t be concerned with how level your floor is, be concerned with how flat it is.

When there is a significant amount of movement on the substrate of a tiled floor or wall it may lead to grout cracking. When this happens it will leave what looks like a crack in the grout where it has come away from the tile. Unless your grout was installed very recently this is always due to movement in the tile. If your grout is new it may be caused by incorrectly mixed grout. With grout that has been doing this for a while it may lead to whole chunks of grout coming loose and leaving large voids in your grout lines.

While it may be tempting to simply mix up some more grout and fill these voids you need to know that it will not last. If you do this it will fill the grout lines just like new but over time will lead to the same problem. Grout over grout is not a permanent solution.

Why it won’t last

The first reason is that when you go over the top of grout that is already cured with new grout, there is no adhesion to the old grout. It will instead simply create a layer of grout on top of the old grout. These layers have no way of  sticking to each other. When you grout tile the grout actually sticks to the sides of the tile rather than whatever substrate is beneath it. While it will stick to the substrate at the bottom of the grout lines to an extent, it is not a permanent bond. Attempting to grout over the top of old grout is simply stacking two seperate layers of grout. It will always remain two seperate layers.

The second reason is no matter how much of the old grout you may take out to install new, if you do not fix the actual reason the grout failed in the first place, eventually the same thing will happen again. As with any problem you may encounter with a tile installation, you must figure out the initial cause and fix it to prevent repeated problems. This is an involved process which I will cover in a different article. For now I’ll stick with the solution for the grout problem. [continue reading…]

One of the most asked questions by do-it-yourselfer’s is whether they should use caulk (or silicone) or grout in the corners. Industry standards state that a flexible material be used at all changes of plane. But! – if you ask a hundred different professionals you will more than likely receive fifty of each answer.  While there are pros and cons of each, I am in the camp that uses silicone (you can use caulk). That being the case, I will discuss using grout first. I’m backwards like that.

Using Grout at Changes of Plane

While the phrase “changes of plane” may sound a bit uppity or technical – it’s not. It simply describes the corner or edge of any surface that changes direction such as a corner, a wall to a floor, or a wall to the tub edge. Many professionals simply grout that corner as they do any other space between the tiles. There are a couple of things that must be taken into consideration before choosing this method.

1. Your walls and the framing of your shower must be absolutely rock solid. I do mean absolutely. Grout is a cement-based product and as such is not meant to flex. If your wall moves your grout will eventually crack – it’s that simple.
2. The space between the tiles at the change of plane must be large enough (for sanded grout) or small enough (for non-sanded grout) to be able to support the grout. That simply means that if you are using sanded grout you cannot butt the tiles against each other at the corner and expect to be able to force grout into it. It will not stay if the grout has no grout line to hold onto – if it is simply attempting to grab onto the face of the tiles at a 90 degree angle. There must be a grout line at the changes of plane.
3. You must decide you are going to use grout at the changes of plane before you install the tile. You can then make sure to leave a line for the grout as well as adding additional support for any spots that may move even the tiniest bit (which it should not do anyway).

If you have taken the above points into consideration and still decide to use grout in the corners – go ahead. The big advantages of using grout here is that it will match all the grout lines and it will never have to be replaced. So although extra care must be taken to properly use grout at your plane changes, the advantages for some people are worth the extra time. [continue reading…]

The size of grout lines for tile is something that comes up on almost every tile installation. The secret no professional will tell you is there is really no set or absolute proper size for your grout lines. There are some guidelines that need to be followed but the actual size is more of a personal choice than it is a set width.

Grout line guidelines

Since grout line widths are generally a personal preference I’ll let you know what mine are. I separate most tiles into three different categories:

• Small format tile – Tiles up to and including 8 X 8 inches square.
• Regular – 12 X 12 up to 16 X 16 inches square.
• Large format tile – 18 X 18 inches and larger.

These are not technically official category names for tile sizes – it’s just what I call them. I’m weird like that.

Small format tile

A lot of smaller format tiles are self-spacing. That means that on either two or four sides of each tile there are what are called “lugs”. Lugged tile have small bumps or protrusions on the sides which are set directly against the tile next to it. Most of these tiles are made specifically for vertical applications, those are shower walls, backsplashes, etc., rather than floors.

The lugs on the tiles allow them to be stacked atop one another and keep the grout lines consistent throughout the installation. For tiles with lugs on only two sides of each tile you must make sure they are all stacked in the same direction, that the lugs are not butted against each other. Normally the lugs will create grout lines that are 1/32 to 1/16 of an inch.

For small format tiles that do not have lugs I will usually use 1/16″ spacers. Depending upon the texture and consistency of the tiles I may use 1/8″ spacers on occasion. For instance 8 inch slate tiles will usually look better with a slightly larger grout line.

If you prefer larger grout lines but have lugged tiles – don’t panic. You can still use spacers with the lugs. To ensure consistency you need to make sure that you either put the spacers between all the lugs or between the spaces the lugs are not. In other words do not put a spacer between the lugs on one tile and between spaces where there are not lugs on another. To figure out the size of your grout lines you also need to add the size of the lugs to the size of the spacer if you use the spacers between them. [continue reading…]