I recently re-did a bathroom with Ceramic tile, and my wife liked the results so much, she asked me to do the same in the kitchen. I followed exactly the same procedure, but the results are not nearly as good. In the kitchen, the Grout looks terrible. It looked ok for a while, but then it started cracking. In a couple of places, it actually crumbled. In other places, It didn't exactly crack, but it kind of "peeled away" from the tile, so there is a definite line at the point where the grout and the tile meet.
I have resigned myself to re-doing it, but before I do, I want to know what could have gone wrong? What sort of things cause grout to crack?
One other thing - the tile has beveled edges on top, so in order to make the kitchen floor smoother, the grout lays over the top a little bit, rather than just being down in the cracks. Is this a problem?