In the kitchen there are ceramic floor tiles 12x12. Either the floor is settling or the tiles were put down wrong years ago. The kitchen, guest bath and laundry share the same area and tile, so you can't just change one area without the other. (Skip to "Question", bottom if you don't need details)
Problem: Some tiles are cracked and the grout falls out. I had it professionally cleaned and the grout replaced where it needed it. I then sealed it so the grout won't get dirty. With very little usage the grout is starting to flake or brake off in certain areas. I would redo the kitchen tiles but found out that the same tiles ($6.00 ea) are now 1/4 inch smaller then the ones I have so I can just replace one or two tiles but redo the whole kitchen. But that would mean I would have to tear out the bathroom, laundry and kitchen to replace all the tiles when only the kitchen has problems. There really isn't a good place to start to retile without redoing it all.
Question: Is there an additive/glue I can add to the grout to keep it from falling out again?