How to treat wall surface before hanging wallpaper

Each type of wall surface needs to be treated accordingly:

New drywall: Make sure the drywall is free of contaminants such as dust, dirt and mildew. Joints and spackled areas should be thoroughly cured and sanded smooth. Best results are obtained when the moisture content of the drywall is at or less than 5 percent. Apply a good quality opaque/white primer.

Paint: Test painted surfaces for moisture sensitivity. Hold a wet sponge or cloth to the paint surface for 15 seconds, then rub the surface vigorously with a cloth. If little or a slight amount of paint is removed, paint should be sound. If all or a large quantity is removed, the wall should be washed with ammonia and water or sanded and washed to remove the paint. Painted walls should also be tested for adhesion. Cut three small x's into the painted wall surface, then apply a piece of clear cellophane tape over the x's. Yank the tape off vigorously. Inspect the tape for any paint: no paint flakes indicates good adhesion. Paint flakes on the tape indicate that the paint adhesion is not adequate for hanging wallpaper. The wall should be sanded with a coarse sandpaper to remove or break through the old paint. All painted walls should be primed with a good quality opaque/white primer.

Walls where old wallpaper has been removed: Old adhesives should be removed by sanding or by using adhesive remover. Rinse the wall and allow to dry. Old adhesives can act as a food source for mold and mildew and makes the wall surface uneven and difficult to bond to. If the wall shows any signs of existing mold or mildew, it should be washed with a diluted household bleach solution and thoroughly rinsed and allowed to dry. Repair the wall as necessary. Prime with a good quality wallpaper primer. If the old wallpaper is peel-able, remove both the top and bottom layer of wallpaper.

Existing wallpaper: Make sure the wallpaper is firmly bonded to the wall and has no lifting seams or loose spots. You can check for poor adhesion by rubbing your hand over the surface of the wallpaper and listening for a "crackling" sound. Make sure the surface is clean and free of any dirt or grease. If the surface is textured or patterned, consider the wallpaper you are about to hang and decide what primers are suitable.

Paneling: Prime with adhesion promoting primer. Groves should be filled, then re-primed and/or an appropriate wall liner should be used. For best results, use a clay-based adhesive. Some wallpaper will require additional priming of the wall liner. See wall liner instructions for priming, installation and adhesive recommendations.

All of these procedures should be followed by an application of a good quality wallpaper primer.

If there are any questions concerning the surface to be covered, test installations of at least three strips applied three days in advance of main installation is recommended, or follow manufacturer's instructions.