QUESTIONRemoving the old tile - I have a 15 year old outdoor patio consisting of 12 x 12 ceramic tiles placed over a cement foundation. The tiles are cracking and I would like to remove tiles (slippery, indoor tiles) and replace them with outdoor tile. My problem is how do I remove the tiles along with the adhesive to make the cement "clean and level" to accept new tiles?
ANSWER - First thing is to determine why the tile cracked, so you can make sure your new installation does not crack.
If the cracks are structural (vertical movement) you have to do some major repairs. If the cracks are simply shrinkage cracks then you can apply a crack isolation sheet over it and then install the tile to it.
What to use to remove the tile depends on what was used to attach them to the concrete. If it was a cementitious thin-set adhesive and the tile is well bonded then you need to use a chisel and hammer or use a jack hammer with a wide chisel end. Next either chisel, grind or blast the slab to remove all of the adhesive and to leave a nice clean and abraded surface. If too much of the slab came with the tile then you need to apply a cementitious patch material to flatten, level or slope the surface. Assuming the cracks are shrinkage cracks then apply a crack isolation membrane and thin-set the tile to the membrane with a good quality latex or polymer modified thin-set. For a list of major manufacturers who make these products go to our website under Links and Resources under Installation Products (click here). Good Luck!