Not all plaster wall surfaces will support the tile properly.
Tile over plaster walls.
The problem otherwise is that grout is porous and any slight crack will cause moisture and mold on any other surface.
Follow manufacturer instructions to a tee.
You may tile over existing tile painted or unpainted drywall plaster and textured walls.
However tiling over tile can add quite a bit of thickness so make sure your wall can handle the weight.
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 re not sure if you have lead paint test kits are available.
Cover with cement board tape off.
That is true you cannot tile over plaster if that s your plan.
You should not tile over wallpaper glossy surfaces lead paint or plywood.
But with cement board.
Can you lay tile on plaster walls.
Mold does not grow on cement.
Also now it s been plastered you will be restricting yourself to a tile with a max weight of about 16 kg m2.
You would have to remove the plaster and replace it not with drywall run from a contractor who says that.
If plaster is any way compromised you should tear out to studs and start over.
Adhesive grout and tile 20kg max weight onto plaster.
Mix degreasing cleaner with water in a bucket using a dilution recommended by the cleaner manufacturer.
Both painted and bare plaster allows for the installation of tile.
Scrub the wall tiles with diluted degreasing cleaner and a nylon scrub brush.
Testing the wall for durability.
Or flatten walls with a latex modified skim coat product.
Add a diverter and shower line in the wall.
It used to be very common to put tile up on whatever the wall was and seal the the tile.
Bring plumbing to code.
Loose paint must be scraped.
Then rinse the wall with a water dampened.