tiles on eneven tiles???

[violet17]

Hi, Just back from holiday to find Hubby has tried to take tiles off wall in bathroom but too many holes in plaster work so panicked and re-tiled to give us a base to tile in mosaic glass unfortunately his tiles are all uneven . I can't see how we can tile on uneven tiles is there a product that i can use on top of the tiles to even out the wall so i can tile on top and get a good finish. I live in France and we don't know any plasters or how to find one.please give advice feeling as if there is no hope to problem!! Thanks