The divot method is a way to utilize a regular three piece clamping drain with a topical waterproofing product. Topical waterproofing includes sheet membranes such as Schluter Kerdi and liquid membranes such as Laticrete Hydroban or Custom’s Redgard.
What you need to know:
If you are familiar with waterproofing a shower floor with Schluter Kerdi, or any other topical membrane, including liquids, you know that you need a topical drain. These differ from a regular clamping drain because they do not have an integrated weep system.
Don’t have any idea what that means? Then you need to do more research before you attempt to build and waterproof a shower floor. Seriously. You need to know what you are working with before building a waterproof box (your shower) inside of a wooden structure (your house) and expecting it to prevent damage that could compromise the structure (your bankruptcy). You can start with my free waterproofing manual. It will give you good overall information on the various waterproofing methods.
This post describes the top, or overlay, of the curb for your traditionally waterproofed shower floor with a liner. The stuff you stick the tile to. It assumes (my posts often assume quite a bit – they are condescending little bastards…) that you already have the curb substrate built, your preslope in, and the liner installed. Those steps are described in the first couple of posts showing you how to build all that stuff here: How to create a shower floor for tile.
First I’ll answer a few questions I get constantly:
NO, YOU CAN NOT INSTALL HARDIBACKER TO YOUR CURB FOR YOUR TILE! (Unless you are using a topical waterproofing method for your shower floor.) There is no way to attach the hardi to your liner without puncturing it, which renders your waterproofing efforts useless. You need to have wire lath over your liner to hold it to the curb and wet mud installed over that to form a substrate for your tile.
Oftentimes (sorry, I did type that with my pinkie in the air…) you don’t have access to the floor beneath your shower in order to install your drain. Not usually a problem unless your drain pipe beneath the floor is hanging in the wind! Okay, not hanging in the wind, but not absolutely sturdy either.
It’s difficult to get a good seal when installing your drain if your drain pipe isn’t solid. It pushes down as you try to push the drain onto it. That doesn’t work. So get yourself some string. Or wire. Or anything else you can wrap around your drain pipe beneath the floor and up through the hole for the drain.
DO NOT use one of your wife’s scarves! Not that I’ve, umm, done that…
One of the most frequent questions I get asked is ‘What size and type of trowel should I use for…?’ The proper answer to that is ‘whichever trowel gives you the proper coverage for your particular installation’.
So there really isn’t one perfect answer to that question, a lot of factors are involved. But I’ll try to help you out.
Proper thinset coverage
The first thing you need to know is what constitutes proper coverage.As stated in ANSI A108.5 3.3.2 for installation of tile on floors; “Average uniform contact area shall not be less than 80% except on exterior or shower installations where contact area shall be 95% when no less than three tiles or tile assemblies are removed for inspection. The 80% or 95% coverage shall be sufficiently distributed to give full support to the tile with particular attention to this support under all corners of the tile.”
When using Kerdi for your shower floor you need to make a hole in it for the drain. If you don’t then you simply have a shallow swimming pool rather than a shower. This hole must be the exact size and it must be in the correct spot. There are two ways to do this.
The first way is to install your membrane on the floor then cut out your hole for the drain. While this method works, I’m not a fan. It leaves open the possibility of cutting more than just your membrane (where it needs to be cut), slipping and damaging the drain or messing up the bond of the membrane around the drain where you need it to be bonded (accidentally debonding a portion of the membrane while you’re cutting the hole).
It works, but there’s a better way. I’m assuming here that you’ve already cut your hole in the floor, installed the drain and mud deck and cut your kerdi membrane to the correct size for your floor – the width of your floor plus four inches, by the length of your floor plus four inches. That is your floor size plus two inches up each wall. Got that? Good, let’s move on.
The wonderful folks at Laticrete sent me a linear drain to play with. And you know me – I bastardized it until it was virtually unrecognizable, ran it through the paces and did things you really shouldn’t do with nice, high-end products like this.
And it survived. Word on the street is that they read my blog, probably for comic relief and to instruct people what NOT to do with their products. So I’m sure they knew this when they sent it… I mean honestly, I soaked their grout in cherry Kool-aid for a week, how could they NOT know?
I did, however, put it to good use in a very cool shower. This is a brief overview of the installation of that drain.
In Tile and Stone Sealers Part 1 I explained how sealers work. If you haven’t yet read that please do so. It will give you a base understanding of how they get into your tile and what they protect against. It will help you understand what you’re looking for and also help decode some of the terms you may find here.
When choosing a sealer the first decision you should make is what you are trying to protect against. Silicone-based sealers protect against water-based stains – coffee, tea, beer Pepsi, stuff like that. Fluoropolymer-based sealers protect against oil-based stains – cooking oil, body oil, shampoo, stuff like that.
Ever get tired of trying to scrub that ‘white’ (it started life as white, anyway) acrylic or fiberglass shower base? Ever try to take one out? It’s stuck, isn’t it? Ever get tired of rhetorical questions?
In order to create a shower floor for tile you must first remove that big, ugly base which seemingly attracts dirt from some unknown aspect of the magnetic force of the universe. It’s not really the magnetic force – it just feels like it. It’s actually the rubber force – as in the rubber gasket around the drain pipe.
Rather than attempting to pry the base out of there until you’re almost ready to fire up the propane torch and see if it will actually melt (it will), you can simply pry the ring from around the drain pipe and lift it out. Really.
I’ve finally gone and done something worthwhile! Well, that’s a matter of opinion, I guess, namely mine. I have written complete manuals on properly building and waterproofing your shower utilizing the different waterproofing methods.
Each manual describes a specific method so you don’t get bogged down with a bunch of information you don’t need for your chosen project. Not sure which method you want? Not sure which methods are available? Didn’t know there were different methods? Start with the free manual here: Shower Waterproofing Manual. That will help you decide which one you want to use based on time, skill and cost.
Once you figure that out you can get the manual that is specific to your particular project. Although these are all mostly completed it’s a whole process to get them ready for you guys. It’s difficult to describe but it includes half a watermelon, platypus eyelashes and a full moon – weird, right? Let’s just say I’ve been writing the damn things for close to two years – it’s not a short process.
Anyway, I do have two of them all finished up, uploaded and ready for you to devour!
I have the complete shower manual utilizing the traditional waterproofing method for walls and floors. This will walk you through the entire process for complete shower floor and wall building and waterproofing. If you are going to have a tiled shower floor and walls and need to construct the entire thing – this is the one you need. You can get it here: Complete traditional shower waterproofing method (Price goes up next week!)
And I have the manual using the traditional method for just your shower walls. If you already have a tub or pre-formed base (like acrylic or Swanstone) this is the one you need. You can get it here: Traditional waterproofing for your shower walls
You can always just click the yellow highlighted ‘Library’ tab at the top to see what’s currently available. If you have any questions just feel free to ask them in any of the comment sections on the site. I always answer them – I’m just super cool like that. I will add the new manuals to the library section as I finish them up.
I get a LOT of questions from my readers about basic shower construction. I understand that my readers don’t consider this stuff basic and there’s no problem with that. The problem is that I end up answering the same questions over and over and over… So, to save what very little is left of my sanity (which is a number roughly equivalent to absolute zero) I will cover some basic things here so I can simply reply ‘read this’.
If you’ve been channeled to this page by one of my smart-ass comments please take no offense to it, I’m here to help. Please understand that I currently have over 12,000 comments (questions) on this site (seriously) which I’ve answered – every one of them. I’m just trying to make your life (mine) easier. I will continue to answer every question I’m asked, I’m just super cool like that. If, after reading through this, you still have questions feel free to ask them in the comments below.
You can also download my shower waterproofing manual which should answer a lot of questions and cover basic techniques and methods you may be confused about. Go ahead, it’s free. So without further ado (doesn’t even look like a word, does it?) let’s get on with it. (For all my readers who feel the need to correct me: I KNOW it’s actually ‘adieu’ – I was being facetious. Thanks. )
Another request from one of my readers, this time concerning weep holes. As you may know I answer every question I’m asked here on my site when I sober up get home from work. I have tried to explain in the comments section several times where to create weep holes in a tub or shower (acrylic base) tile installation and now realize it’s a difficult thing to do with words.
So when Kurt asked me to clarify exactly where they go a stroke of genius hit me! (Yeah, I’m slow sometimes) I have pictures. Well, not exactly pictures of the weep holes themselves, but I can at least let you know where they are.
When you have a tub which does not have specific spaces for a weep hole you need to ‘create’ them in your caulk line. Let me back up here a second and explain what weep holes are and why you need them.