Tiling over bathroom paint

[mikedigitales]

I'm redecorating my small bathroom and am pretty much a set to go but am a bit worried that one of the walls (end of the room, with a window) is painted with bathroom paint. It is pretty sound, not flakey, but is a bit shiny and I'm worried the adhesive might not stick properly. I'm using BAL WhiteStar with 20x25cm tiles, already have a tanking kit for the other end of the bathroom (wetest end of the room). Would using some of the leftover acrylic primer that came in my tanking kit help the tiles stick on the painted wall?

Really not sure if this is something to worry about or not?

[mikedigitales]

If you stick some carpet tape on the paint and press it on firmly and leave it for 10 minutes then peel it off. If the paint comes with the tape it’s best to remove the paint by sanding it or scraping it (don’t use chemicals). If the paint does not come off with the tape you should be able to tile over it ;-)

[tictic]

9/10 better to key it first with a Stanley then do the tape test....

IMO always better to take the paint off...where ever possible....