I've decided to re-tile our 1/4 bath as a learning experience. It's a small area that I thought would give me a feel for it. We've pulled the old vinyl up and repaired the 'interesting' toilet plumbing installed by the builder. (6 wax rings!)
Now I've got all the vinyl up and I'm scraping up all the bits of residual glue and what looks like paper. My first question is: how pristine does this floor need to be? I'm pulling up anything I can feel but if there is something left that looks white and not the gray of the concrete, but I can't feel it, do I need to get a wire brush and scrub it off? I've hit it with a wire brush drill attachment and it will come up that way, eventually, but I'm not sure what it is I'm taking off at this point.
Second question: I'm going to pour a thin layer of self-leveling compound to even everything up and fill some small holes. What should I use as a barrier to stop it from running under the drywall? Cardboard? Something that won't stick to it? Just thin it out at the edges?
YouTube has been letting me down on these points!
Thanks for your help.