In general, it's best to strip wallpaper when preparing a wall for a new preparation such as new wallpaper or a coat of paint, but in some instances--if stripping the wallpaper would damage the wall, for instance--it's best to leave the existing wallpaper in place. When applying wallpaper over existing wallpaper, thorough preparation helps ensure satisfactory results. Specifically, proper technique helps the new wallpaper adhere and prevents premature peeling over time.
Things You'll Need
- Wallpaper sizing
- Spackling paste
- Putty knife
- Warm water
- Wallpaper tray
- Paint tray
- Paint roller
- Level or chalk line
- Measuring tape
- Utility knife
- Wallpaper brush
Video of the Day
Remove all trim and accessories such as outlet and switch covers from the walls you wish to cover with new wallpaper. Lay a dropcloth to protect flooring.
Sand walls thoroughly with coarse sandpaper, followed by finer sandpaper. Peel away any pieces of wallpaper that have already started peeling and sand in the area of the peeling or seam to smooth the transition. Find high and low spots on the wall by closing your eyes and running your hand lightly over each area of the wall. Sand down high spots. Vacuum away sanding dust residue.
Fill in low spots, nail holes and flaws, using spackling paste pushed into the area with a putty knife. Scrape away the excess. Allow paste to set according to manufacturer's instructions. Sand to blend into the rest of the wall and apply additional paste and repeat sanding as needed.
Clean the wall with a damp cloth. Allow it to dry completely.
Roll a sealing primer made specifically for application before hanging wallpaper onto the walls. Allow the primer to set according to manufacturer's instructions. Apply a second coat or roll on wallpaper sizing if the wallpaper is not completely covered.
Measure the wallpaper roll and use the measuring tape and level or chalk line to mark where the wallpaper's vertical seams will fall.
Cut the wallpaper into a strip slightly longer than what you require to cover the wall from ceiling to floor. Fill the wallpaper tray with warm water and soak the wallpaper in it to activate the adhesive. Most wallpaper comes backed with adhesive, but if yours doesn't, apply wallpaper adhesive instead with a paint roller.
Remove the wallpaper from the water and fold it into a manageable bundle by putting wet adhesive sides together. Folding the wallpaper onto itself is called "booking".
Unfold the wallpaper as you apply it. Starting at the uppermost part of the wall at an obstacle such as a doorway, apply the top of the wallpaper strip at the top of the wall, smoothing as you go with your hand. After the wallpaper is generally stuck to the wall, smooth the wallpaper from top to bottom and side to side with a brush to push out any air trapped underneath.
Hang additional strips of wallpaper, progressing in order from the strip that started the room and cutting the strips after you have visually matched the pattern to the previous strip. Start at the top and brush downward.
Trim excess paper at the baseboards by running a putty knife horizontally along the baseboard and following on top of it with a utility knife for a straight edge.