I just bought a new condo from a property investor who never lived in the place - he picked out basic options through out the place, including a basic white ceramic tile floor in the kitchen, foyer and bathroom areas. I plan to install a new ceramic tile now - any advice on how I should tackle this, specifically - can I laying the new tile over the existing tile - Or is it best to tear out the existing and start from scratch installing the new tile? Since the floor is not even a year old, I figured it might be ok to lay right on top of that but that could cause problems in the future I'm guessing? Help?? Thanks in advance friends!

I'm replacing a hallway carpet with used ceramic tiles . I'm using used tiles which were layed about 5 years ago in a similar condo as mine. New tiles of the style I'm trying to match are unavailable. How much of the old material do I have to remove from the Back of the tiles to ensure they will not come loose after they are installed? Do you have any suggestions on how to remove the old material? The only way I have been able to remove the material has been to chip it off with a Hammer and chisel Any suggestions you may make will be greatly appreciated. Jim