Johnny is correct that the most ideal is to tile over unfinished drywall.
Prime walls prior to tile john bridge.
The technical folks from thinset manufacturers that i ve talked to prefer not to apply thinset over paint due to the fact that wet thinset has a relatively high ph level and will work on softening the paint until it dries.
Or prime and paint the entire wall room before starting with your tile project.
Do a precise measurement of the surface.
Start with planning your wall tile installation.
Prime an area larger than you plan to tile to minimize the cut in work when you paint the rest of the room.
My question is do i need to prime a wall somehow.
Previously painted textured drywall prep.
However i have never seen tiling over primer as being an issue.
When i said mortared and screwed i meant glued and screwed with construction adhesive to the old plaster ceiling and screwed through the joists which.
My tiler said to get some pva for priming after looking on the web i understand pva should not be used for bathroom tiling priming.
Prime the surface prior to the tiling.
Like davy and cx i don t prime drywall before tiling.
If i m using it to prime under tile we re back to the original question of this post.
Are either of the pairs of walls plumb.
Patch any cracks or holes with spackling compound and sand smooth.
If so you might pull off both last runs.
Sand any high or uneven spots to create a level surface prior to tile installation.
Sandbagger are you suggesting the zinsser instead of tiling or under the tile to prime the green board.
Remodeling contractor just outside the glass city.
Vacuum clean and wipe the walls.
If you are tiling over brightly colored walls with translucent tiles apply primer to the walls prior to sanding so the color doesn t bleed through the tiles.
Tile the bogus wall first getting the cut to fill the slant close enough the plumb walls tile can cover.
Start by removing any molding switch plates outlet covers and other hardware attached to the area being tiled.
Prime the wall with thinset and allow ample drying time.
Use the type of thinset mortar.
Or do i just put the adhesive straight on the wall and stick the tiles on like i always thought.
I would not want to tile over a latex paint however or over drywall mud texture as the mud will emulsify with the thinset and not bond as well.
The technique of layering means for you to apply one layer of filler and let it dry before you apply the next coat.
Best of luck a great place for information comraderie and a sucker punch.