05-02-2014, 04:28 PM
I replaced some tiles in our kitchen right where we stand the most when preparing food, so it's likely the same "most traffic" thing. Mine cracked rather than just coming up, so I had to remove the broken ones without disturbing the others.
I used a grout saw to saw down the grout around the ones that I was going to replace to keep from disturbing the others. I was then able to get a prybar under the edge of the tiles I was going to remove and popped them out. I then used a chisel to get up the thinset from the substrate and to gently chip it off the back of the tiles that hadn't broken. When I replaced them I put new thinset on the floor and also back-buttered the tiles to make sure I had a good bond. It's been a couple of years and so far, so good.
One thing you might want to check (if you can get to it) is the floor at the base of the stairs to make sure there is substantial structure under that part of the floor. If the floor flexes when you hit the landing as you come down the stairs, it doesn't surprise me the tiles came loose. If you can get to the joists under that area, you might want to beef it up right at the base of the stairs to make sure it's not flexing.
I used a grout saw to saw down the grout around the ones that I was going to replace to keep from disturbing the others. I was then able to get a prybar under the edge of the tiles I was going to remove and popped them out. I then used a chisel to get up the thinset from the substrate and to gently chip it off the back of the tiles that hadn't broken. When I replaced them I put new thinset on the floor and also back-buttered the tiles to make sure I had a good bond. It's been a couple of years and so far, so good.
One thing you might want to check (if you can get to it) is the floor at the base of the stairs to make sure there is substantial structure under that part of the floor. If the floor flexes when you hit the landing as you come down the stairs, it doesn't surprise me the tiles came loose. If you can get to the joists under that area, you might want to beef it up right at the base of the stairs to make sure it's not flexing.