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.
You need to figure out where your control joints will be located before you grout. I will sometimes take pieces of blue tape and mark that line every few feet or so ’cause I get dizzy easily. The less grout you get in it the better. You will need to clean out any grout that ends up in there so try not to let it end up in there.
Once you have your floor grouted and before the grout is cured (do this right after you grout) you need to clean out the control joint. I use a ‘hook knife’ which is just a curved blade that I can run down the joint to loosen all the grout (that’s what that funny looking tool is in the picture).
After you do that you can take your shop-vac and suck all the grout out of that line. Be careful not to remove grout in the adjacent lines! Keep your hose an inch or so away from the tile. (Wow, that sentence is ripe for a very bad joke) In photo 1 you can see the grout in the lines crossing the control joint – you want to simply cut straight down the control joint across these lines. When you vacuum out the grout be careful not to remove grout from those lines also. (If you click on photo 2 you can see what I mean)
Photo 3 shows the control joint all scraped out. Again, you can click on it (it’s huge) and see where I’ve cut across the other grout lines. Then just vacuum it all out. Photo 4 shows the line ready for caulk. Most manufacturers have a matching grout or silicone for whatever color grout you choose. If not, Laticrete has a large number of colored silicones called Latasil and color charts to see which would best match your grout.
Once you have your control joint all cleaned out just fill it up to the top with matching caulk or silicone. Make sure you get the line full – you don’t want any hollow spots in the line which will eventually end up cracking or disappearing. You can run a damp sponge down the line once you get it full to smooth out the top.
You may need to do this more than once depending on the width of your grout lines. After the caulk or silicone has cured it may shrink a bit too much to look acceptable. If that is the case then go ahead and run another bead down the line to fill it back in.
That’s it. Photo 5 shows the completed control joint. I used a matching caulk on this installation which will darken as it cures. Once cured the color will match the grout exactly.
And there you go. Now you can go out and be a tile ninja and berate people because they have no idea what a control joint is in relation to a tile installation. You can look like a superstar because you can explain to people why their tile looks like a teepee (Read my last post) or why their floor sounded like a gunshot last night. That’ll scare the hell out of you – believe me.
If you have any questions at all about whether your installation needs a control joint or not – just ask me in the comments below! I’ll answer you when I get home from work – really – read around. I’m fairly personable.
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