Tommy Mac Discussions › Forums › Fix-it Forum: Home Improvement & Do It Yourself Repair Forum › Thinset on concrete › Hope this helps
Bonding to the Dry-Loc should not be a problem with most adhesives. I’m not sure about thinsets. They probably would do better bonding directly to the concrete, but maybe adhering to the paint won’t be a problem either.
As for any adhesive, you will be relying on the Dry-Loc’s adhesive qualities with the concrete, to hold down your tiles, no matter how good your tile adhesive is. It’s kind of like a coat of good paint on a coat of bad paint. If the bad paint begins to separate from the surface, the good paint will come off with it. If the Dry-Loc fails, so will your tiles.
Of course, Dry-Loc works well in these situations, so there is a good chance everything will be fine.
Good luck.