Wallpaper Glue Is Stuck on the Walls

Preparation

• Before you begin your wallpaper glue removal, you need to know what type of wall is beneath the glue. Homes that predate the mid-20th century often have plaster walls, which are smooth and hard; homes built in subsequent decades usually have drywall walls, which are paper-based, softer and more porous. You can be a little more aggressive when removing stuck wallpaper glue from plaster, but drywall can't take as much moisture application or scraping without damaging the wall. Tap the wall to figure out if it's plaster or drywall: only drywall is hollow sounding. Also, lay drop cloths over furniture and flooring since stuck-on glue and paper chunks may fall away from the wall.

Traditional Methods: Wetting, Scraping and Steaming

• Soften your stuck-on wallpaper and glue by spraying its surface with a solution of wallpaper removal product and warm water. You can also roll this mixture onto the wall with a clean paint roller. After allowing the mixture 15 minutes or more to loosen the glue, gently scrape beneath the stuck section with a putty knife. If you have drywall walls and feel resistance, quit scraping since you may pull off drywall paper. If you can't remove the stuck glue after wetting and scraping it, the next step for plaster walls is steaming the stuck-on section. You can dry using a steamer on drywall walls, but the moisture may damage your walls.

Sanding

• If the other techniques don't work, or if your glue is stuck on drywall walls that aren't responding to your wallpaper removal product, you can gently sand off the stuck-on glue. Use a sanding block with 220-grit sandpaper on the section of stuck glue until you've completely worn the stubborn residue away. Since some invisible glue may remain even after sanding, wipe the walls with a rag soaked in trisodium phosphate and water solution; if trisodium phosphate isn't available in your community, use a vinegar and water solution.

Prevention

• Wallpaper paste sticks especially firmly to unprimed drywall walls, and often removing old, stuck wallpaper paste results in also removing drywall paper from the wall's surface. Before you wallpaper a drywall wall, prime or paint your walls or hang wallpaper liner before starting the job. Before any large wallpapering project, you should test a small, inconspicuous section of wall. Apply the paper, allow it to dry and attempt to remove it. If you haven't yet removed the old wallpaper on your unprimed drywall walls, you could paint over the wallpaper and bypass the wallpaper removal process completely.