Sometimes I get asked how to backbutter mosaic tiles. I constantly have to tell people that you really don’t need to. There are very few instances when you’ll need to backbutter a mosaic tile. Normally if you feel the need to backbutter mosaics it is easier to simply use a larger trowel on your substrate.
I get quite a few questions here concerning cracking grout on a shower bench. In some form or another people are mostly asking whether they should caulk or grout the outside corner, where the bench top meets the vertical tile on the face. The reason for asking me this, however, is what I will address in this post.
Most people begin with something like ‘my grout has cracked and now water is getting behind my tile and my bench is starting to swell, there was an eclipse, my dog has burst into flames…it’s a whole thing. Should I grout or caulk that?’
Unfortunately this happens a lot (the bench, not the eclipse or k-9 flames…), and everyone thinks about it backwards. It is not the grout (or missing grout) that caused water to leak into your bench and swell the framing, it was the swelling of the framing that caused your grout to crack. Tile and grout are not waterproof. The reason you have this issue is because your bench was not properly waterproofed before tile was installed.
When I answer questions on my site I am always telling people to backbutter their tile. It has recently been brought to my attention that normal people (the ones who don’t stand in showers all day) have no idea what that means.
Backbuttering tile simply means spreading a flat layer of thinset onto the back of the tile before installing it on your wall or floor or whatever.
First you have to ‘comb’ the thinset onto the substrate – that means it is spread with the notched side of the trowel leaving little ridges. It should look like that first photo there on the right with the ridges all combed in one direction. This allows any air to escape from beneath your tile more easily.
Everything I normally write is about building your brand new awesome shower. However, to do that you must first remove the old, outdated, non-awesome shower. There are several ways to do this, I’m gonna show you the easiest.
A lot of people will go in and chip every tile off the wall (don’t laugh, they do it…), then remove the drywall (or what’s left of it) to get down to the studs in order to build the new stuff. You don’t need to do that. It’s time-consuming, messy and will give you a fairly crappy attitude about the project right from the get-go. (Did I just type ‘get-go’??? I need a beer…)
Most existing tiled showers being torn out are ‘builder’s grade’ showers, that means 4×4 or 6×6 tiles with a bullnose tile, normally 2″ wide, along the edges. Chipping each tile off the wall will waste an entire day. So you’re going to remove entire portions of the wall at a time.
The first thing you want to do is chip off the bullnose, or little rounded pieces, along the edges (and top, if you’re not going to the ceiling) of the shower. If you notice in the photo to the right I’ve already done this. [click to continue…]
I will describe simple framing of a bench with your substrate over it. You can also use after-market, pre-fabricated benches. Better Benches (google it) attach directly to your wall substrate, the top gets filled with deck mud and it gets tile. There are also several different Styrofoam products available from companies like Schluter and Laticrete. They are made from the same type of foam used for their shower bases. Although they are ‘foam’, once tiled they are more than sturdy enough to support your tile.
While you ‘can’ build a bench in your shower after you form the shower floor with deck mud, it’s always easier to make your bench first. Your floor substrate is flat, your shower floor (should be) sloped. It’s difficult to build a level bench on a sloped floor.
But you can do it if you wanna.
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.”
Let me translate that for you:
When you build a shower you will eventually need to make some holes in it – it’s just part of the overall process. You’ll need to install frames or hinges for your shower doors, grab bars, shower curtain rods, a picture of your pet iguana – whatever. The problem is that now you have that completely waterproof shower you really don’t want to go poking holes into the waterproofing.
No matter which waterproofing method you’ve used any fastener penetrations will have to punch a hole into it. You want to make sure you install your screws properly in order to maintain the integrity of the waterproofing. You don’t want to ruin all your hard work because you need to drive a screw through it!
The first thing you need to do is mark the exact locations of your screw holes. Most things like grab bars come with little templates you can hold up and get exact placement. With shower door frames and stuff like that you can hold up the frame piece and mark the correct location.
In my previous post I showed you how to make a niche for your shower out of Kerdi-board. If you haven’t read that you probably should. It’s gonna be really difficult to install a Kerdi-board niche if you don’t have one.
When I install shower niches I prefer for the edge of the niche to be lined up with the grout lines in the tile installation. This way it looks like it belongs there rather than looking like something that was an afterthought (I HATE that…). So it requires planning.
When I build my niche I make it the same size as the tile I’m installing (or a multiple of those tiles, like two tiles high by one tile wide). This will be the INSIDE dimension of your niche when you build it. So again – more planning.
Previously I’ve shown you how to build a shower niche using backerboard (or drywall) and Schluter’s Kerdi membrane. I did it that way for years – and still do on occasion. However, I have discovered a way to create a niche very easily with much less work and time involved – Kerdi-board.
For the purposes of this post you will need 1/2″ kerdi-board (3.5-4 square feet for a 2′ x 1′ niche) and a tube of kerdi-fix. Kerdi-fix is a urethane sealant made specifically for kerdi products and waterproofs seams. I am building a 2 foot high niche by 1 foot wide.
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.