Tiling on painted drywall. Is primer needed?

[Klicka]

Should I prime where the wall is painted when tiling on a partially painted plaster wall?

 

[sixten88]

Yes, always primer.

 

[Larsa]

Stupid to take a chance, the primer is meant to ensure good adhesion and prevent the substrate from drawing out moisture from the adhesive too quickly. Maybe it works well, maybe it becomes crap….

 

[Plupp 156538]

The question is how well the fix adheres to the paint, is it glossy?
You may need to rough it up a bit, and the primer probably won't help with that as it prevents, as previously mentioned, the water in the fix from being absorbed into the surface instead of curing the fix.

 

[Klicka]

Raising the question again. I have purchased Bostik primer:


Will it be sufficient as a primer? It says "Before filling with Bostik floor filling compound and before setting tiles with adhesives."

The wall is partially repaired and partially painted.

I don't want the tile adhesive to make the drywall "bubble" when I start tiling.