I want to tile a concrete floor that has 1950s tile already installed on part of it. The problem is, one edge is out of flat with a slope change of almost 1" in the last 2 feet. Other than that slope change, the sections are individually flat. The slope change is where the previous owner apparently put leveling compound to overcome some defect in the slab. The compound and the slab are stable and have been for years.
I planned to use a 1/4" slip sheet over the whole floor, and use smaller tiles that may be more forgiving to the slope change. If I apply more leveling compound I can move that 1" slope change to be over 4 or 6' versus the last two feet, but it's too much compound to cover the whole 24' room I think.
What do I need to do before I lay tile?
Ive added a sketch. Im not certain of the make up below the leveling compound, but there is certainly a footer in there. I also have concern disturbing the old likely asbestos tiles.