How do you remove wallpaper glue?

To remove wallpaper glue, spray down the walls with a commercial wallpaper stripper, then scrape the paste off the walls with a putty knife, broad knife or plastic scraper and clean the walls with water and a soft cloth. Experts also recommend softening wallpaper paste with extremely hot water.

Avoid using excess water on drywall. It absorbs more water than plaster and can crumble when exposed to too much moisture.

1. Prepare the walls
Apply wallpaper stripper or extremely hot water to the walls after the top layer of wallpaper is removed. This softens the backing and weakens the paste's bond to the plaster or drywall. Dilute stripper with water in a one-gallon sprayer for faster application.
2. Scrape the paste off the walls
Choose a tool for scraping off the wallpaper glue. Broad knives and putty knives work well for this purpose, but plastic scrapers might inflict less damage when wielded with inexperienced hands. Scrape all the glue residue off the walls until the surface is clean and smooth. Apply a gel stripping agent for stubborn spots.
3. Clean the surface
Wipe down the walls with a moist cloth. Return with the scraper if any remaining clumps of glue are discovered. Allow the walls to dry for at least 48 hours before painting them or applying new wallpaper.