tiling on plaster board

[diymarkw]

I have almost completed tiling a ground floor cloakroom with 50 x 17.5 tiles and ready mixed adhesive.. Walls are plasterboard with one coat of mist emulsion. Just learned to my horror that I should have keyed the surface and primed it. I had no apparent problems with tiles not sticking until I got to the recess around the window. Havent grouted yet and given the wall tiles a good push and they seem ok.
I have plaster boarded bathrooms to do which have not been painted. Intending to tile with60 x 30 tiles and powder adhesive.
Should I prime these?

[wine~o]

I wouldn't unless it's a wet area. there's a sticky about tiling and weight somewhere near the top of the tiling forum.

[paul the spread]

...