Wallpaper can work magic when you need to cover up troublesome surfaces. And wallpaper is far more than just a fix-it material. Thousands of gorgeous wallpapers offer patterns and crisp colors that cannot be duplicated with paint.
But wallpaper is less welcome when it’s time to remove it. Traditional wallpaper is hard to remove from the wall, requiring special liquid remover or wallpaper steamer tools. If you’re able to get the paper, wallpaper glue may remain. Painting over the glue, rather than removing it, may seem like an inviting idea. But can you really do this? If so, are there any precautions you need to take?
Can You Paint Over Wallpaper Glue?
Painting over wallpaper glue is possible but not recommended because the paint may reactivate the glue or the glue may weaken the paint. You may take some precautions that will lock the glue behind a coating of oil-based primer. But these procedures can take as long or even longer than removing the wallpaper glue.
- Reactivating the glue: Most interior wall paints are water-based; most wallpaper glues are water-based, as well. Starches or kaolin (a type of clay) are the base ingredients for wallpaper glue. So, when you mix the paint with the glue, you reactivate the glue. This can create a clumpy or wavy texture.
- Weakening the paint: By mixing glue into the paint, you adulterate the paint and compromise the paint’s strength and its ability to fully stick to the wall. Later on, the paint may prematurely crack and start to chip off.
What Wallpaper Glue Is Made Of
Wallpaper glue or paste, often called wallcovering adhesive, is a general-purpose adhesive product used for hanging all types of wallcoverings. Typically, these include lightweight non-pasted wallpaper, pre-pasted wallpaper, and vinyl wallpaper.
Wallpaper glue has pronounced tack, yet it also has an initial degree of slip for easy positioning. Due to the size and unwieldy nature of the wallpaper, it may be necessary to adjust the wallpaper once it is on the wall. Wallpaper glue allows for slight adjustments.
How to Paint Over Wallpaper Glue
While painting over wallpaper glue is not recommended due to its significant limitations, observe a few tips if you think you'd like to try it.
Sand the Glue
Lightly sand the wallpaper glue with #220-grit sandpaper to bring down its high spots. Sanding too hard will abrade the underlying drywall paper, so go easy.
Clean the Wall
Clean off the sanding debris with a brush attachment on a shop vacuum. Do not clean with water.
Apply Oil-Based Primer
Apply an oil-based primer to separate the water-soluble wallpaper paste from the water-rich latex paint. The primer effectively will create an impermeable barrier between the two coatings.
Let the Primer Fully Dry
Let the oil-bassed primer fully dry. The recoat time for oil-based paints and primers ranges from eight to 24 hours. It's usually best to wait as long as possible before recoating oil-based paint.
Add a Skim Coat
A skim coat is a thin layer of drywall joint compound. This is applied with a drywall knife or paint roller. Using a drywall knife lets you smooth out the coat with the sharp edge of the knife. A paint roller applies a thick coat of compound that later will require more sanding.
Sand the Skim Coat
Sand the skim coat smooth with fine-grit sandpaper. Skim coats can produce highly smooth walls.
Paint the Skim Coat
After the skim coat dries, the wall can be painted in a conventional manner with interior acrylic-latex paint. Be sure to first use a primer on the new surface before painting.
Add a Second Coat of Paint
Let the paint fully cure, then add another layer of paint, as white spots from the glue may be visible through the first new layer of paint.
How to Remove Wallpaper Glue
To remove wallpaper glue from a wall, first try to lightly wash the glue off. If this does not work, sand it off.
In a clean one-gallon bucket, mix hot water, 1 cup of vinegar, and 1 teaspoon of dish soap. Stir lightly to avoid frothing up the mixture into suds.
Apply Solution to Wall
Wearing gloves, submerge a sponge in the solution, then wring it out. Apply the sponge to the wall. Work in small areas and only lightly rub the wall. Do not try to soak the wall with the water.
Scrape Glue Off
After a couple of passes with the sponge, follow up with a putty knife or a drywall knife. Work quickly to avoid the glue drying up on you again. Keep the knife at a low angle to avoid gouging the surface.
Let Wall Dry
If rubbing or scraping off the glue does not work, next try to sand it off. First, let the wall thoroughly dry. Depending on the temperature and airflow in the room, it may take a full day or even two for the walls to completely dry.
Sand With Fine-Grit Sandpaper
Place #220 grit sandpaper on an electric oscillating sander. Sand the wall but avoid pressing hard on the sander. Follow each pass with your free hand to check for smoothness.
2 Alternatives to Removing or Painting Over Wallpaper Glue
If painting over the wallpaper glue or removing it still does not work—or if you just prefer an alternative—try adding paneling or adding another layer of wallpaper.
- Paneling: Wood paneling, whether real wood, veneer wood, or artificial, can completely cover up the wallpaper glue. Paneling can completely turn around the look of your room and give it a dramatically new appearance.
- Wallpaper: New wallpaper can cover up either old wallpaper or wallpaper glue. If you find a wallpaper brand and pattern that you love, this can be a great way to quickly cover up the old glue.