I have finally managed to remove all the ceramic tiles from my 70s style bathroom ( well,paid my 15yr old �50!) prior to fitting a new bathroom suite & shower. All wall were tiled and I know they will need replastering before new tiles/painting (by an expert, not me!)] Problem - 70% of them left their adhesive behind, v thick and v difficult to remove. Have tried sponging down with water & a wallpaper scraper, but still lots left. Does it all have to be removed, and how can I do it?