Bring plumbing to code.
Tile over plaster wall.
Testing the wall for durability.
The wall is plaster lathe and is good condition.
If plaster is any way compromised you should tear out to studs and start over.
Follow manufacturer instructions to a tee.
However tiling over tile can add quite a bit of thickness so make sure your wall can handle the weight.
If you re not sure if you have lead paint test kits are available.
Can you lay tile on plaster walls.
Cover with cement board tape off.
Tile over plaster wall.
Loose paint must be scraped.
Both painted and bare plaster allows for the installation of tile.
If i aggressively sand or even strip the paint can i apply the tile over the plaster.
You may tile over existing tile painted or unpainted drywall plaster and textured walls.
You should not tile over wallpaper glossy surfaces lead paint or plywood.
Not all plaster wall surfaces will support the tile properly.
Add a diverter and shower line in the wall.