Michael has recently pointed out (a bit more eloquently than I would have) that I have indeed been a lazy bastard and have not yet written this post. Apparently people actually want to know how to do stuff I do – weird, right? So here you go – making your ceiling shiny.
The main problem people have with tiling a ceiling is getting the tile to stay where they put it. Believe me, I’ve had more than one tile fall on my noggin before I figured out what works. Since I’m relatively certain you aren’t very interested in what doesn’t work I’ll tell you what does, it saves headaches – literally.
You do not need a $75 bag of non-sag thinset to tile a ceiling. Non-sag thinset is basically just thinset that is sticky – it’s great stuff! It’s also expensive stuff. You can accomplish the same with the $15 bag of regular modified thinset.
Before you start hanging head-bashers (ceiling tile) you should, as always, have the substrate properly prepared. They do not always need to be waterproof. It’s a good idea and never hurts, but it isn’t always necessary. The photos of the shower I have here was in a small bathroom with limited ventilation so I waterproofed the ceiling as well.
You should always ensure that the ceiling substrate is screwed onto the joists securely. There is a whole different set of physics at work on a horizontal surface that don’t apply to your vertical wall tile. Basically the entire weight of the full tile is pulling constantly on every inch of your tile. So you want whatever it is attached to securely fastened.
The first thing we’re gonna do is burn your thinset into the ceiling substrate – in this case it’s Kerdi. ‘Burning’ thinset into something simply means using the flat side of your trowel and skim-coating the surface. I use the term a lot and that’s all it means. It fills all the areas of your substrate or tile (whatever you’re burning it into) and ensures that your thinset gets a good grab on whatever it is. Photo 1 shows about half of the ceiling with thinset burned into it.
Photo 2 shows the back of one of the tiles we’re installing on the ceiling. See all those white lines? Those are actually raised just the tiniest bit so the back of the tile is not entirely smooth. You need to burn thinset onto the back of the tile. This will fill all those little squares and ensure that you have every area on the back of your tile adhering to thinset. You want to give it every square inch possible to grab onto that ceiling. Photos 3 and 4 show the tile with thinset burned into the back.
Now you want to flip your trowel over and comb thinset onto the back of the tile. “Combing” thinset is another term I use often – it just means using the notched side of your trowel to, well, comb the little lines all in the same direction. That is – wait for it – Photo 5. You are not allowed to give me crap about my lack of photo labeling originality!
Now we get to the secret ingredient of ceiling tile installation – suction! All that thinset you combed into pretty little lines on the back of your tile? Take the end of your trowel and draw a bulls-eye in it like Photo 6 (believe it or not I was totally sober when I drew that ‘circle’). This bulls-eye is what keeps the tile from dropping on your head – because that hurts like hell. You should just take my word for it on that one without testing it for yourself.
Now that you have your bulls-eye on the back of your tile go ahead and press it up onto your ceiling. (Photo 7) You want to push hard! You will actually hear air squishing out from inside that circle of thinset. This creates suction on the back of your tile and helps the tile stay put until the thinset cures. Once that happens it doesn’t matter what shape your thinset is on the back. The suction is needed to keep it there only until the thinset is cured.
Continue to do this with the rest of your ceiling tile – every one of them, even the cut tiles. Draw the bulls-eye and stick it up, draw the bulls-eye and stick it up, etc., etc. To get them to stay in the proper spot with correct grout line size and lined up you can actually stick spacers in them (Photo 8 ) and use blue painter’s tape to keep them in the proper spot relative to one another. Just get a piece of tape about 3 -4 inches long and stick half of it to one tile then pull that tile slightly toward the one next to it and stick the tape to the next one. This will keep each tile tightly against the spacer and the tile next to it so your grout lines don’t go all wonky. (Did I just type ‘wonky’??? Jesus…)
You do not need to comb thinset onto the ceiling. I know that sounds counter-intuitive but simply burning the thinset into the substrate will give you plenty of grab onto the tile. You do not need to be concerned with 100% support as you would on a floor – no one will walk on your ceiling except Spiderman – he’s an ass sometimes. But he always pays to replace any ceiling tile he cracks.
Once you get all your tile up there you can still push them upward to get them flat with each other. Just lay your straight-edge across them as you would on a floor and make any adjustments needed. You do not want to pull them down to adjust them! You will lose the suction doing this. You want them really close to flat before you make any final adjustments.
You can see in Photo 9 (if you click on it) that there are two tiles that have slightly low corners which I still need to push up (they’re in the back row – the left corner of tile two and the entire front edge of tile four). Always push up to make adjustments. If your tile is way out of whack pull it down as you are setting them to add or take away thinset on the back. Do not pull them down once you have them all set and taped.
That’s it. That’s how you get tile to stick on the ceiling with regular thinset. Easy. Okay, it’s easy for me. You may have a bit of a learning curve.
There are two basic designs for your ceiling tile. You can either line up all the grout lines (which requires planning!) or you can install the ceiling tile on-point (diagonally). This is simply a personal preference – whichever you think would look better in your shower is the one you should choose. The photos here have all the grout lines lined up. If you do not install your ceiling tile diagonally please line up your grout lines. If you don’t it looks like crap – that simple.
When installing tile on the ceiling you want to install the tile on the shower walls all the way up to the last row before the ceiling – as I’ve done in these photos. If you are lining up your grout lines rather than installing them diagonally you can then draw lines on your ceiling as guides to where your tiles should be. You don’t see lines in these photos because I use a laser – I’m Star Wars-ey like that.
Once you get all your ceiling tile up then install your last row of wall tile. This will help hold all the tile around the edges as well. Be sure not to cut the last row of wall tile so that it barely fits in there! You need an expansion joint of about 1/16″ and you do not want the pressure of a wall tile that is not short enough pushing one side of the ceiling tile up – the other side will push down – leverage, you know. Cut them about 1/16″ shorter (plus your regular grout line size for the line below it) than your measurement and use plastic wedges for that gap. And when you are finished – caulk or silicone that space, don’t grout it.
The thinset I’m using is a basic modified thinset – nothing special. It’s Versabond which is commonly sold at Home Depot. You should know this, just to avoid confusion about an issue that is confusing enough anyway. Schluter recommends UNmodified thinset for the Kerdi membrane. If you choose to use modified thinset over the kerdi membrane it will void your warranty! Just be aware of that.
I use modified for two reasons: 1) I prefer modified thinset for everything – period. I give my own warranty to my customers which happens to be longer than Schluter’s warranty anyway. I take that risk and choose to do so – consciously. Should you choose to use modified thinset over kerdi you should be aware of this. And no – it does not create any problems that I have ever been aware of. Doesn’t mean it won’t, just means I have never heard of it. And 2) I’m a rebel like that.
If you have any questions at all please feel free to leave a comment and ask there – I’ll respond when I sober up! The gist of this post was shrunk down into a handy little four paragraph email for TileTips. You can click that link for more information or simply sign up in the box at the top right (under the pretty picture).
This post was brought to life by the suggestion of one of my readers in a comment. I really do read them! So I would like to thank Michael for kicking me in the ass and making me do something productive! My wife thanks you, too. If there is a particular subject you would like to see a post about just let me know – I’m a wealth of useless information.
UPDATE! A lot of people have asked me if their particular size of tile would work using this method – yes, it will. The size of the tile is rarely a factor. Think about it like this: A 2′ x 2′ tile is four square feet. If one square foot of tile weighs five pounds and one 2′ x 2′ tile weighs twenty pounds – it still weighs five pounds / square foot. It weighs the same – it just takes up more area at once.
Here are some photos of some 2′ x 2′ tiles I installed on a ceiling – they weighed 23 lbs. each! And they hung up there just fine. So if you think you’ll have problems with your little 18″ tiles – well, you won’t.