I am in the process of preparing a basement room for installation of 13" x 13" ceramic floor tile. The floor had carpet on it, which gave off a "rotting" smell. I pulled off the carpet and found a layer of linoleum tile underneath. This was likely an original installation when the house was built in 1964. some of the tile lifts off quite easily, but others require some persuasion to remove. Underneath the tile is a layer of black adhesive. I have attempted to remove by scraping, but only the heavier bits of adhesive peel away, still leaving a thin layer of black against the concrete. I've tried using a chemical stripper in one small area. This did lift off most of the adhesive, but a slight film remains on the floor. I don't think a thinset morter will stick to this reliably. Any ideas on how to deal with this?

Just wondering if anybody has tried to cut cement board with a dremmel tool. I am building a surround and need to cut holes for shower heads etc. Instead of buying carbide blades I am hoping to be able to use something like a dremmel tool instead. is this possible. Thanks.