I'm having old (30 plus years), damaged slate tiles removed and replacing it with ceramic tiles. I've discovered there is cement underlayment under the slate tiles. I'm having this work done for me and so far the floor looks like grenades have hit it. There are pot holes. How in the world are you suppose to remove these slates tiles that have been adhered to cement?? And, how do you repair the flooring to eventually lay down cement board and ceramic tiles?? I'm sick to my stomach.
Whoever is doing the work for you will know what to do. It is a job. If you are sick to your stomach, I would advise you watch what you are doing in the kitchen before you poison yourself with your cooking.
A thin layer of new mortar will fill in and cover the rough surface. Cement board shouldn't even be necessary.
As long as the cement is intact and not cracked, you can set the new tile right over it. Just knock off any high spots that are left after getting up the old tile, then trowel on new thinset mortar using a 3/8x1/4 square-notched trowel. As long as the existing cement is sound you do not need to remove it; this is an ideal base for new mortar. If it is cracked, this means that the plywood underlayment is moving up and down because it was not secured properly to the floor joists. But if the cement is in good shape there is no need to remove it. (Usually jobs that were done by craftsmen years ago who knew what they were doing are better than anything you can get today; you would not want to rip out a perfectly good base and replace it with something substandard.) As a matter of fact, if the existing tile floor has no loose tiles and no cracks, you really don't even have to remove it if you can go with the additional 1/2 or so in height that a new tile floor would entail. Just mortar right over it.
get one of those ice chippers the big ones and chip away at them and after that put a new bed of concrete down. i can't find a picture...but its like a big chisel with a long handle that you use to get at ice in the winter..we use to use it to get tiles off of the floor... the working ends like 5 inches flat.
