We had our kitchen remodeled two years ago. Replaced cabinetry and appliances, but kept tile floor. Our kitchen is u-shaped, and with the new cabinets, the one side of the U was pushed out six inches. We had extra tiles for the floor, and the contractor reworked the tile to deal with that issue. Everything was fine, except that the grout in one area of the new area kept crumbling. We redid it a couple times, but it kept happening. Now we just noticed the four tiles around that area have cracked. What would cause this? We know how to replace the tile (though at this point, I don't think we have any more extra tiles) but what could be the underlying cause?
You hit the nail on the head without meaning to.
It's what's under the tile that's causing it to crack.
No way to know until until you get the tile out.
Not enough thin set, someone tryed using something instead of thiin set.