Cracked tile and cracked concrete slab?

Question

Greetings

I have installed travertine over concrete a month or so ago. I have yet to grout and have noticed that some tiles have cracked. We I took up a tile, I noticed that the slab was cracked in the same place. Doing a little research on the internet, I found this is common. However, more experienced tilers put down something between the tile and slab, namely a crack isolation membrane. I am worried that if I take a tile up, put down the isolation membrane and then put the tile one top that it may make the tile slightly higher than surrounding tiles that I don't need to replace.

I am in a jam and need help....any takers??

Many thanks in advance.

Answer 1

You might try the GE silicone sealer. Make sure it's GE genuine silicone. When it dries, not only it is an adhesive but provides a cushion between the concrete and tile. The same amount of thickness as the thinset for other tiles may be all you need. Then all the tiles will be at even height.

Answer 2

If this is on a new slab, you may want to give it at least 28 days to cure. (the concrete). If not you should just remove any tiles that are over the crack, float the crack out with thin set or floor patch then reinstall the tiles. I would only redo this part. Make sure that your patch is as close and smooth as the rest of the concrete.

Answer 3

The membrane is only 16th of an inch thick, unless you put your thin set or mastic down smooth, you should have enough lee way with a 1/4 notched trowel  to make a seamless repair.

You might consider taking up the tiles around the cracks to make sure you have complete coverage.

I did this 2 years ago on a garage apartment remodel and the cracks have never come back.