Can you tile on top of wallpaper ?

I think with a question such as this you should get a profesional tiler in other wise (a) They will fall off tiling over wall paper (b) I doubt you have an clue on how to tile a wall. Whatever you do don't use wallpaper paste to stick them to the plaster board.

BB
April 2011

No, just make sure that you use long nails to secure the tiles to the wall.

TC
April 2011