Removing tile from bathroom walls can be a labor-intensive, messy process, and the work is not over once the tile has been removed. Clumps of tile adhesive, divots from where part of the drywall came off with the tile, and other marks will probably be left on the wall, as well. So before retiling, painting or putting up wallpaper you will need to repair and smooth over your bathroom walls.
Dissolve the tile adhesive, which is also called mastic. The quickest way is to use a commercial mastic remover. Follow the directions on the bottle for application. Usually, the remover is applied to the remaining clumps of adhesive with a rag, brush or sponge, then left to sit for a few minutes.
Scrape off the adhesive. Once the adhesive has been softened by the tile remover, scrape it off with a putty knife.
Fill in any holes or divots in the walls. Use the putty knife and some Spackle. Fill in the holes, then smooth them over with the putty knife. Let dry overnight.
Sand down any rough edges left over, which may include tiny amounts of adhesive or Spackle. Wipe down the walls with a wet cloth to remove any traces of dust left over from the sanding.
Spray on a texture over the patched-up areas of the wall to match that of the rest of the walls. Most walls in residential homes have what is called an orange-peel texture. Let dry overnight.