We have a 40 year old house with a concrete slab floor.
We would like to put porcelain tile down on this floor.
Because of the age of the floor, and the are we live in, there's been some shifting, cracking, and settling.
We had a contractor come by to make sure there wasn't any structural problems, and he assured us that the floor was "normal" for the area, age, etc. and that there weren't any glaring problems (like the walls shifting).
We have filled the cracks, and tried some small boxes of concrete to help get the floor leveled, but we're just not sure that we're doing it correctly, or how much we have to do, etc.