H
Handyeire
You can’t use a ready mixed over paint, the moisture will bring the paint off.
My nephew tiled his mothers kitchen and bathroom with readymix over painted walls 15 years ago and the tiles are still on the wall to this day.
I also tiled my large floor with ready mix without priming 18years ago and not one tile has came loose. Ive been meaning to upgrade in the last few years but just cant get the time however, come Jan, ill let yous know how tough or easy they came up.
Not everything is set in stone!