Wash Wall

• Fill a pump spray bottle with warm water and 1 tbsp. of dishwashing liquid per 32 ounces of water. The enzymes in the dishwashing liquid will help break down any remaining wallpaper paste and bits of wallpaper still sticking to the wall. Spray an area of the wall and wait 5 minutes. Clean off any remaining material by rubbing briskly with a sponge.
  
  

Trisodium Phosphate Rinse

• A solution of trisodium phosphate (TSP) and hot water will remove material that you cannot see. Sponge the solution onto the wall starting at the top, scrub lightly with a sponge and wipe dry with a clean towel. Add 1/2 cup of TSP to 2 gallons of hot water.
  
  

Final Rinse

• A final rinse ensures that you have a clean surface on which to apply primer or new wallpaper. Rinse the wall with clean water and a clean sponge, wringing out the sponge after each pass across the wall. Replace the water when it begins to look dingy. Dry the wall with a clean towel, then leave it for 48 hours to dry out completely before you apply the new finish.