I am helping my daughter sort out her recently acquired house. The current problem is cracked floor tiles at the entrance of the kitchen from the lounge.
I have started to carefully remove these and found the cause. The kitchen is a concrete floor while the lounge is suspended wood, sadly the lounge floor extends a few inches into the kitchen.
The tiles have cracked where the wood has flexed. Now how can I stop this from happening again when I replace the cracked tiles? Putting cement over the wood will not work, as that is what was already done, a thicker layer would raise the floor at that point unacceptably.
Or replace the floorboards with the ply if you have access to the joists either side. Or reinforce the boards with a couple of screws at every joist. Rather than the wood flexing, it could just be movement as you walk on them.
It is a point of "how to prevent the timber from expanding and contracting more than the concrete" that's the problem. The timber is going to move a lot more than you can really prevent, and so the only solution I can think of, is to lay the new tiles on a bed of soft silicone sealant. Remember to remove any and all the old adhesives from the floor before putting anything else down on top of it, or you could end up with a point that makes the tile rock and will break it even quicker.
A thick bed of silicone will allow the tiles to move around much more than solid adhesives, but the grout will also crack more because of this movement.
So you're stuck with straight replacement using the same technique as the original, or going with silicone and replacing the grout rather than the whole tiles ever so often.
Just remove the tiles back to the solid floor and finish off with a bit of wood trim or something. You can't really lay tiles directly on to a suspended floor.
A sheet of 2 or 3mm steel under each tile would stop it cracking and not raise the floor level by much. A flexible grout would also stop cracks appearing between the tiles.
thats guaranteed to make the tiles all crack. I have exactly that, and oh boy, its crazy paving tiling. Tiles need total rigidity, any bending of the support and they crack like eggs. Basically tiles have very little strength when bent, thus must be isolated absolutely from any bending forces.
I'd stiffen the wood any and every way possible. Thick sheet steel under the tiles might possibly help, but only if absolutely rigid, and you'd need far more than 2mm for that. More in the region of 7-10mm I'd think. Less than that is going to be pointless.
If there is enough depth for cement, you might possibly try using a
1:1.5 mix plus added fibres. This lot is going to be hugely stronger than what might well be just 6:1 or 4:1 there now. But you still need to get the wood as rigid as poss. Replacing 3/4" pine boards with 3/4" ply would help some too, if they run the right way to make that practical. In fact better would be to use even thicker boards, and shave them down where they cross the joists. Thick ply is not cheap, but it may well be worth it to make this job work.
Tiles can be glued back together using epoxy adhesive: try to get some the same colour as the tiles though :)
In short its not easy to make this work, you'll need to employ every means possible and cross your fingers.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.