Last year about this time I re-grouted our bathroom tile but the tiles have cracks and they move around when you walk on them. This has made some of the grout break and come apart again. Here is a picture of one of the cracked tiles. They were like this when we bought the house.
I decided to try to glue the cracks together to help them not crack more or the grout to break apart. To do this I got some glue from the store.
And of course I needed to re-grout the tile. I first removed all the grout that was broken. I found that this tile was not even attached anymore, so the only solution for my tile problem is re-tiling the floor completely. But that will have to wait and I will just have to keep re-grouting the tile until that time.
And after 24 hours I have re-grouted tile. Next time I plan on caulking the entire tile area then hopefully I will not have to re-grout anymore.