I am going to tile a bathroom floor. It now has sheet vinyl with 3/4" plywood under that. Is it necessary to remove the sheet vinyl? My only concern is that there will be glue left behind for sure. Its not attached to the floor very well right now.
Second, I like to use Hardee Board. Is 1/4" ok for the floor? 3/4" plywood is below it.
Also, I've heard that you're supposed to use thinset under the hardee board? Should the thinset be modified or non-modified? They said only Holmes on Homes which one to use but it was too quick and couldn't write it down. I know modified is used for the walls, but does it go between plywood and hardee board too?