Also keep the walls you are about to tile free of moisture dust and grease.
Sealing plaster walls before tiling.
Pva is not suitable for tiling for various reasons and this has been debated many times here in the forum.
Before you get to it you should level the bathroom the kitchen and or the hallway walls.
When applying tile to a plastered surface it is important not to overload the weight of what the plaster will take before failure occurs plaster will support about 20kg m2 or about a 9mm thickness of ceramic tile.
This way the adhesive will stick properly and last in the long run if you are using a good product.
Adhesive grout and tile 20kg max weight onto plaster.
If in doubt prime the walls is a general rule.
Otherwise a few complications might occur.
You didn t say what adhesive you are going to use but one thing that is absolutely definate do not use pva.
New plaster work should be fully dried before tiling work is commenced this drying time varies upon temperatures but can take up to 4 weeks before fully cured.
Don t use paint glue pva wall paper paste only use the primer recommended by the adhesive manufacturer of your chosen tile adhesive.
If you choose a heavier tile you will need to overboard with a backaboard.
You want the tile adhesive to have something to grab onto.
Thoroughly vacuum the area and give the wall a once over with a damp sponge or cleaning cloth.
Sand with a medium grit sandpaper to create a uniform surface that s not too smooth.
I did question the rep about this and he was adamant that new plaster should be pva d because if not the plaster sucks the moisture from the adhesive too quickly therefore it doesn t set properly.
Use a proper acrylic based tiling primer sucha s bal prime apd or ardex p51.