We are trying to install slate tile over an existing concrete floor that was previously painted. Is there any type of membrane that can be installed over this without having to scrape the paint but will also act as a moisture barrier. Please help. Thank you.
Hate to be the bearer of bad news donnavan, but every thinset/self leveller rep I've spoken to (and I have asked many times) strongly recommends that painted or sealed concrete be etched prior to tile installation.
I'm not that familiar with concrete sub-floor options, but maybe some of the other guys on here will have a recommendation to that effect if you don't want to etch the concrete.