Oftentimes, the next step after stripping wallpaper is repairing walls where drywall or plaster has been torn off as well. When wallpaper is first applied in new homes, the interior finisher seldom primes the drywall or plaster wall surface beneath. Follow these guidelines below to repair drywall and plaster surfaces after stripping wallpaper.
Step 1 - Clean Off Old Wallpaper Glue
Wash off the wall surface, especially around the holes and rips, with a solution of trisodium phosphate and water, mixed according to the container directions. This will clear off rough glue bumps before you start to refinish the surface.
Step 2 - Sand Around the Edge of the Ripped Drywall or Plaster
Smooth off the torn edges of the drywall surface or plaster with a medium-grit sandpaper (#80 to #100), then lightly with fine-grit #200 sandpaper. This will create a smoother base for the resurfacing compound.
Step 3 - Apply the Resurfacing Compound
To resurface drywall, use standard drywall spackle resurfacing compound, available ready-mixed at building supply centers. If you are refinishing plaster, obtain a plaster mixing kit and follow the directions to make new plaster. Stir the plaster in the bucket with a mixing paddle attached to a power drill, on low speed.
Apply your resurfacing compound or plaster with a short, broad putty knife, in downward strokes starting one inch above the hole or rip. Spread the compound out smoothly with a smaller putty knife, to a depth of 1/4 inch. For deeper holes and gouges, apply a thicker layer of compound, about 1/2 inch deep.
Step 4 - Smooth Out the Compound
Smooth out the wet compound with a wide, long putty knife until it is as even as possible and free of knife-edge lines. It will shrink as it dries so be sure you have covered the hole all the way to make the edges invisible. Allow the compound or plaster to dry thoroughly to an even white color.
Step 5 - Sand the Repaired Spots
Put on your face mask and open windows and doors into the room for the best ventilation. Sand over the repaired spots with medium #80 to #100 sandpaper attached to a sandpaper block. The block provides a flat surface for best contact with the compound or plaster and prevents abrasion of your fingers.
Work over the spots until they are smooth and even to the touch around the edges and in the center. Finish sanding with the fine-grit #200 sandpaper. There should be virtually no difference between the texture of the drywall or plaster and the refinished spot.
Step 6 - Apply Primer
To ensure your drywall is ready for painting or re-papering, paint on a coat of drywall primer over the entire wall. Use the primer recommended by the paint manufacturer for a plaster wall surface.
Step 7 - Clean up Your Materials
Dispose of leftover trisodium phosphate solution and plaster mix according to the manufacturer's directions.
The wallpaper has been stripped, and your walls are now repaired. Now, let the painting fun begin!