Wallpaper can be difficult to apply because you need a smooth surface for sliding these large sheet goods into position. And wallpaper is almost always difficult to remove since it has a tendency to grab onto the wall and not let go.
But there is a product that is simple to apply and that helps with both wallpaper application and removal: wallpaper primer. Wallpaper primer helps you hit that sweet spot where the wallpaper sticks well to the wall but not so firmly that removal will damage the surface.
What Is Wallpaper Primer?
Wallpaper primer, sometimes called wallpaper sizing, is a liquid acrylic–based barrier that is applied under wallpaper to assist with installing the wallpaper and with removing the wallpaper at any later time.
What Wallpaper Primer Does
Wallpaper primer fills pores in absorbent surfaces, creating a smoother surface for sliding the wallpaper into position. Flat, matte, or uncoated walls—and even eggshell gloss paints—can create a drag that makes it harder to slide wallpaper and position it.
Wallpaper primer allows more of the wallpaper glue to do its job, rather than being immediately absorbed by the wall's pores.
By providing a shield between the wallpaper glue and the wall, wallpaper primer makes removal easier. Wallpaper glue tightly bonds with its substrate. The more pores available, the greater the bond. Wallpaper primer fills those pores.
Wallpaper primer will not make wallpaper removal completely effortless nor will it ensure that the lower surface remains in pristine condition. But wallpaper primer does make a difference between taking down wallpaper or taking down wallpaper along with lots of paper facing and gypsum core.
How to Know If You Need Wallpaper Primer
Water absorption is one of the key factors in determining whether you should use wallpaper primer. So, it helps to test out the wall with a small amount of water to gauge the rate of absorption.
With clean, clear water in a bowl, flick a few drops of water onto the wall and rub in some of the drops. If the wall turns dark, that means that the surface is quickly absorbing water and likely requires wallpaper primer.
Other factors influence the decision, including paint gloss, age and condition of the paint, and the presence of primer or dust.
Flat or Matte Paint Gloss
Flat or matte paints always need wallpaper primer. Glossy and semi-gloss paints in good condition do not absorb moisture well, so they may not need wallpaper primer.
Paint glosses in the mid-range may or may not need primer. Satin and eggshell glosses have enough sheen to shed some water for a limited time. With these glosses, it's safest to use wallpaper primer.
Old or Poor Condition Paint
Even glossy surfaces that are older can benefit from the application of wallpaper primer because they may have lost some of their gloss. Over time, paint breaks down, especially when subjected to UV rays, even indoors.
Use wallpaper primer on any bare, uncoated surface, especially unprimed, unpainted drywall.
Walls that have only paint primer should be primed with wallpaper primer. Paint primer is flat, so it will readily soak up the wallpaper glue.
Walls that are dusty with drywall or plaster dust can benefit from wallpaper primer. While you should always try to clean off as much dust as possible before applying wallpaper, the wallpaper primer can help absorb and neutralize the dust and help the wallpaper glue stick better.
Assists with removal
Helps preserve walls and paint
May be unnecessary with glossy walls
Can be difficult to find
Applying Wallpaper Primer
To apply wallpaper primer, you'll need many of the same tools you'd use to apply wallpaper: sandpaper, a paint tray and liners, a paint roller with covers, a paintbrush, a putty knife, a screwdriver, and clean rags. You'll also need wallpaper primer and drywall compound or spackle.
Unscrew all wall plates, outlet covers, lights, and any other obstruction on the wall.
Sand Bumps and Fill Gaps
Rub your hand on the wall to feel for bumps or use a straight edge. Lightly sand down bumps with fine grit sandpaper. Fill gaps with drywall compound or spackle.
Wipe down the walls with a damp cloth. The cloth should be wrung out as much as possible. Afterward, open windows or turn on a fan to dry the walls.
Cut in Corners
Open the can and soak the end of the brush in the wallpaper primer. With the brush, cut in the corners with the wallpaper primer.
Roll on Wallpaper Primer
Pour wallpaper primer into a lined paint tray. Soak the roller cover in the product, then roll it out on the paint tray before applying to the wall. Apply one thin coat to the wall, making sure to meet up with all cut-in sections and not leaving any gaps.
Wait Before Wallpapering
Wallpaper primer dries to the touch in 30 minutes, but allow a full 24 hours of curing time before applying the wallpaper.