Just before we bought our house, the owners decided to tile. Unfortunately, they went the cheapest possible route, using ceramic instead of porcelain directly on top of the existing thin 3/4″ ply sub floor. Thus, we have tons of cracks in tiles and grout. Last week I broke down and replaced a bunch of the really bad areas. PITA. But done now and it looks pretty decent except where I had major problems trying to get a piece under the stove.