I am going to tile a guest bathroom. I have removed the linoleum and all adhesive. There is a 1/4 plywood layer over the original subfloor. The floor is dry and clean. Do I need to remove the plywood subfloor before installing the backer board and tile?
No, if the plywood is sound, clean, and flat, it's a perfect surface (unless the built-up layers cause your finished tile floor to sit too high).
