Rich O’Neil, painting contractor and owner, Masterwork Painting & Restoration, replies: Removing old wallpaper is an easy project for most homeowners and well worth the trouble. You just cannot get a decent-looking surface if you leave the paper in place and put paint or new wallpaper over it. If you’re lucky enough to have “strippable” wallpaper, all you have to do is grab a corner and peel off whole sheets. But if the paper sticks stubbornly to the wall, you’ll have to dampen the surface with a concentrated, enzyme-based wallpaper remover that breaks down the adhesive holding it to the wall. With a proper soaking, wallpaper will come off in large swaths, not bits and pieces, and before you know it the whole room will be a blank slate ready to be covered with the finish of your choice. Read on for O’Neil’s step-by-step guide to easy wallpaper removal. Shown: This Old House assistant editor, Sal Vaglica strips wallpaper using a putty knife.
Prep the Walls
Shut off the room’s power at the circuit breaker. Remove all receptacle and switch plates on the wall, and cover the openings with 2-inch painter’s tape. Tape a plastic sheet to the top edge of the baseboards to protect the trim and floor. Roll a scoring tool over the paper in overlapping circles, making tiny cuts for the adhesive remover to penetrate. Aim for 10 perforations per square inch.
Dampen the Wall
Following the directions on the bottle, mix a wallpaper-removing concentrate, such as Dif, with an appropriate amount of hot water. You’ll need about 2 gallons of solution to cover 500 square feet of wall. Pour the solution into a pump sprayer, and spray the wall from the bottom up using the ‘medium mist’ setting. Work around the room three times. The paper should bubble in about 5 minutes.
Peel Back the Wallpaper
If working with a metal putty knife, use sandpaper to dull the sharp corners so that it won’t gouge. Work the knife behind the paper’s top edge where two panels meet, and peel the panel down the wall. If paper sticks to the wall, soak it again before scraping. Place the stripped pieces in a garbage can so that you won’t slip on them.
Scrape Off the Glue
Adhesive residue prevents new wallpaper from adhering and telegraphs through paint. Get rid of it by spraying a 3-foot section of wall with more remover solution and scraping the residue off with a putty knife or wide drywall-taping knife.
Wash the Wall
Immediately after scraping off the residue, wash the section clean with warm water and a sponge mop. Continue this way around the room until all the walls have been scraped and washed from top to bottom.
Test for Trace Adhesive
You can check for residual wallpaper adhesive by spraying the wall with a mix of 1 quart water and 1 ounce povidone-iodone, which will turn any adhesive residue purple. Use denatured alcohol or sand lightly to remove those spots. Let the walls dry for 24 hours, then seal them with an oil-based primer.