Loose floor tiles can be very frustrating. Why is it happening? What’s the cause? What went wrong?
I have a textbook for contractors called the NTCA Reference manual. One of the features of this book is that it has tables and charts that list different tile problems. Then it gives a cause. Then a solution. It’s a great book. In there I looked up loose tile and I counted no less than 30 different causes listed in this book. Some examples: dirty substrates, thinset not mixed correctly, thinset skinned over, not enough thinset, too much thinset, wrong kind of thinset, and on and on…
These are common causes that people point to when dealing with loose tile on their floor. Anyone of them could be the culprit. But I want to talk about a cause that isn’t talked about as much but it’s more common than you may think. The cause being not enough movement.
“Wait a second! Not enough movement?” I can hear already. “If my tiles are loose doesn’t that mean they moved too much?”
Hear me out on this.
Not Enough Movement
There are different kinds of forces that can put stress on a tile installation. Your floor can move up and down. This is known as deflection. Floors can move and expand at different rates. For instance, according to the Ditra Handbook, concrete can move nearly twice the rate that tile moves. Also, the tiles themselves can fluctuate in size. The technical term is Thermal Expansion. As the temperature heats up the tiles expand. It’s not much. But if you get a whole kitchen floor of tiles that all grow very slightly bigger then it doesn’t have to be very much. Things get crowded in a hurry. For example:
Warning: Boring technical calculations ahead! (move down to the next subheading to skip this section)
It’s my understanding that if the temperature of a tile varies by about 35 degrees Fahrenheit that a 12×12 tile can “grow” 1/100th (0.01) inches. So how much does 1/100th of an inch matter? One tile at 1/100th of an inch larger probably doesn’t matter. But over the course of an entire tile floor? It starts to matter.
Say the temperature is 50 degrees in the morning and heats up to 85 in the afternoon. A pretty common scenario. Let’s say that you have six tiles in a row with cement grout in between the joints. Each tile is 1/100th of an inch bigger in the afternoon than it was in the morning. Now let’s say that those six tiles grow a combined 6/100th (0.06) of an inch. 6/100ths if nearly 1/16 inch. Is 1/16th of an inch a big deal?
Demonstrating Movement
In the photo below I have a six-foot metal ruler. The six-foot ruler is sitting flat in between two blocks. Let’s pretend that the ruler is actually six 12 inch tiles in a row with grout in between the joints.
Now, what happens when those tiles grow 1/100th inch each? This US penny is nearly 1/16th of an inch. (0.06 inches according to Google).
With no room to move the middle of the ruler rises.
When tile does this it’s referred to as “tenting”.
But I have loose floor tiles not tenting floor tiles
Now you might say “I may have loose floor tiles but they are definitely not tenting.” Well, what happens when your tile moves some but not to the extreme of making a tent shape? What if they just move a tiny amount? Maybe just enough to come loose? Maybe enough to sound hollow underneath?
Now I’m not saying that your loose floor tiles are definitely caused by not being able to move. But it’s a cause that isn’t talked about a lot. Without allowing for movement your tile is likely to fail.
What can I do about my loose floor tiles?
If you are frustrated with your floor tiles coming loose and want to know how and where to allow for movement, please read this next post:
David Kyle says
In what ive experienced – is that a lot of tilers don’t bond the plywood.
I go to fix a loose floor tile & all the adhesive is stuck to the back of the tile – the plywood is clean as a whistle.
Also – screwing down the plywood. – I screw down at 125mm centres & make sure I screw the subfloor to the joists.
Ive seen lots of horror stories – 6mm ply with 25mm ring shank nails – nailed at 300mm centres with loose floorboards underneath.
DIYTileGuy says
It definitely pays to have the plywood down soundly and securely. I don’t recommend sticking tile directly to plywood but the little bit that I have done of it I noticed the same thing: the adhesive usually comes off pretty clean.
Thanks for the comments!
john t says
what would cause ceramic floor tile to creak when you walk on it on top of a concrete floor..??
DIYTileGuy says
I would think it would have to be loose tiles. I suppose someone could install plywood or hardibacker on top of a concrete subfloor but that would be pretty unusual.
carlos sveto says
Thanks for your illustrative article.
It’s clear that a small variation in expansion can cause tiles to poco. But why could this happen on a tile floor more than 15 or 20 years not having any issue?
Regards,
Carlos
DIYTileGuy says
It’s hard to say what finally causes something to give. A lot of times there are unseen forces at work that are loosening things up over time. I don’t know if that’s the case here or if there was something else that happened.
Eissa Saleh says
Thanks a lot for useful great effort
I need to ask about tiles that are specified as high durable in terms of frost resistance, does this type face more expansion problems if installed in high temperature countries or does not ??
DIYTileGuy says
I don’t think their risk of expansion problems increases. But it’s important to follow the manufacturer’s and local guidelines for expansion joints and movement accommodation.
Tttom says
Any suggestion to replace the tiles. Do you recommend vinyl.?
DIYTileGuy says
This post is the “cure” for the problem that is talked about in this post. https://www.diytileguy.com/movement-joints/
If you can add the appropriate amount of space for the movement that is needed then you can simply reinstall the tiles.
Keith Campbell says
25+ years ago when we had a tiler lay our floors, the supplier said we had a choice of glues; one was the usual cement type and the other was a flexible glue type that allowed for the slabs expansion and contraction without cracking tiles. he said it was good for at least 25 years ???
He apparently was right, even though we had a few loose tiles in the high traffic area of the hallway earlier on,as the time frame came around we had loose tiles, tenting and hollow sounding tiles and crumbling grout in a fair percentage of the total tiled areas.
Have you ever heard of this flexible glue before ?
DIYTileGuy says
The only thing that I can think of that would be available 25 years ago is mastic which you don’t want. My guess would be that what I talked about in this post could be the problem. Tenting and hollow tiles are likely from a lack of movement. A flexible glue wouldn’t help things if the tiles still can’t expand and contract.