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.
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 However, to do that you must first remove the old, outdated, non-awesome shower.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. [continue reading…]
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. )
I am not writing this to tell you why your tile is cracking or why your grout is cracking – I have other posts that may tell you that. (Click on the pretty little links ) If you happen to have Schluter Ditra as your substrate, this post will tell you why either one of the above may be happening.
While Ditra is my preferred membrane for floor tile installation (as well as countertops and tub decks) it absolutely needs to be installed correctly. The two main techniques for this are fairly simple:
Make sure the cavities (waffles) are filled correctly
Install it over an approved substrate (and with the correct type of thinset mortar)
In my previous post I beat you to death with the reasons why you absolutely need a soft joint (control joint) in certain tile installations. Sorry about that, I have a hard time expressing how important they are without being a dick. They”re important – really. So now that I’ve properly reprimanded you it’s time to show you how to do it.
That title right there is absolutely ripe for me to go off on a sophomoric, mildly humorous rant about the viability of inferior illegal plant use. But I’m not gonna do that. (Okay, maybe later…)
A soft joint, or control joint, is simply one grout line, all the way down the length of your installation, that is filled with colored silicone or caulk rather than grout. The purpose of a soft joint is to allow movement in your installation without cracking tiles or grout. When placed properly it will absorb any ‘normal’ seasonal and structural movements inherent in structures.
There are guidelines that need to be followed for a soft joint to be effective. The TCNA guidelines call for a control joint every 20′ – 25′ in each direction for interior installations and every 8′ – 12′ in each direction for exterior installations. Interior installations which are exposed to direct sunlight also need control joints every 8′ – 12′.
Make a hole!!! Ummm, sorry, had a little flashback there for a second. Where was I? Oh yeah, drilling a hole in a tile. When you tile your shower wall you will usually have at least one or two holes that need to be taken out of your tile. This is often a huge pain in the ass and sometimes difficult to do without cracking the tile. So I’m gonna show you how I do it. This will not guarantee that your tile will not crack! It does, however, greatly diminish the possibility. This method works with all ceramics and porcelains as well as natural stones such as granite, marble and travertine.
If at all possible try to lay out your tile so that any pipes or fixtures fall on a grout line. If you can do this you can simply cut a small square out of the edge of it with the wet saw and forgo the whole drillin’ a hole thing. I know, it’s not always possible. In fact it rarely happens in a normal tub surround. So lets drill a hole in that sucker!
I know there are some people out there (not my regular readers like you!) that read what I write and think to themselves ‘okay, but I’m sure that won’t happen with my installation’. So periodically I’m gonna post things like this that show exactly what happens when things aren’t built correctly. And yes, it will happen to yours, too, if the proper steps aren’t taken. If you care to see more train wrecks you can check out my ‘flawed‘ page wherein I post photos of absolutely horrible tile installations which I’ve torn out and replaced.
See that crack in the tile right there? (The line down the center is not a grout line – it’s a crack. You can click on it for a larger version) That bathroom floor is less than eight months old. It was installed with hardibacker over the subfloor and thinset. At least that part is correct, but that was about it. There was no thinset beneath the hardi and the seams between the sheets were not taped and thinsetted. To a lesser extent the correct screws were not used in the hardi – they committed the cardinal sin of using drywall screws in the backerboard. Yeah. Wrong.
As some of you may know (or simply don’t care about – but know anyway) I actually do reply to every question I’m asked on this site. It may take a while for me to sober up enough get enough time away from work to answer it – but I do. As such I am frequently asked the same or similar questions a lot. I’m going to start turning these questions and answers into blog posts to leave myself more beer drinking time to help people with the same problems. So here’s my first one. If you have a suggestion for future posts like these just let me know and I’ll be more than happy to cobble together some similarly ridiculous advice for your problem. I will not share any names or other information with anyone else because – well, it’s none of their damn business – so no homeowners were harmed during the writing of this post.
Here’s the question:
My husband and I have recently tiled our kitchen and laundry room. It is a 35 year old house that had kitchen carpet in both areas. We removed the carpet and old linoleum was underneath. We installed backerboard thinset extra like you suggested on this site, which i read just now to make sure. Now we have something like a fault line running through our grout. We did remove the grout down to the thinset and cleaned out as much as we could then regrouted. Of course it cracked again within 2 weeks of the repair. I do suspect a tile is moving but is there any sure way to know if it is just that tile or more and if so what is the best way to fix it. Also I am not sure why it would move with backerboard under it could it be the floor itself?
My response to this all-too-common question is a bit complicated since it is rarely one specific reason and could be a number of things.
Your grout is cracking for one reason and one reason only: your tile is moving. That’s it. Okay, that’s not it – Unless your grout is non-sanded and was installed in the last 28 days – your tile is moving. That’s it. Yes, 28 days has significance, it is the amount of time it took my teenage son to clean his room. It is also the amount of time it takes for grout to fully cure.
So let’s figure out why your grout is cracking:
Your grout is newly installed – incorrectly
If you do have grout that was installed within the last 28 days then your grout is not actually cracking – it is shrinking. Either your grout lines are too large for non-sanded grout (smaller than 1/8″) or it was incorrectly mixed. NO! You cannot simply mix up more and fill it in. Read this post about adding more grout to your grout lines.
If your grout is not fresh, well, you need to repair the reason your tile is moving. And stop using your pogo stick in the house. Diagnosing the reason your tile is moving is extremely varied. It could be anything from inadequate deflection in your flooring for the type of tile all the way up to and including the aforementioned pogo stick.
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…]
Click here to get an instruction manual for your waterproofing installation
Click Above to have professional TileTips sent directly to your inbox.