How to get wallpaper paste off walls after removal

You’ve spent hours stripping old wallpaper, only to be faced with a sticky, gummy mess of paste residue. Leaving this behind means your new paint job will be bumpy and uneven, and new wallpaper won’t adhere properly. Getting wallpaper paste off walls is a critical step for a professional finish, and it requires the right approach.

The key is to rehydrate the paste. Most wallpaper pastes are water-soluble, meaning water is your primary weapon. However, the type of paste, the age of the wallpaper, and the type of drywall or plaster beneath will dictate the best method.

Assess the paste residue

Before you start scrubbing, take a close look at the paste residue. Is it a thin, almost invisible film, or is it thick, clumpy, and clearly visible? This will help you determine how much effort and what type of solution you’ll need. Thick, old paste might require more aggressive treatment than a thin layer from a recent installation.

Gather your supplies

You’ll need a few essential items:

• Warm water
• Bucket
• Sponge or spray bottle
• Putty knife or scraper (use with caution)
• Microfiber cloths or old rags
• Sugar soap or a TSP substitute (trisodium phosphate)
• A mild detergent
• Optional: Wallpaper steamer
• Optional: White vinegar

Method 1: Warm water and sponge

This is the gentlest and often most effective method for water-soluble pastes.

1. Mix your solution: Fill a bucket with warm water. For slightly tougher residue, you can add a small amount of mild dish soap or white vinegar (about 1/4 cup per gallon of water).
2. Saturate the wall: Dip a sponge into the warm water, wring it out so it’s damp but not dripping, and wipe down a section of the wall. You want to rehydrate the paste without oversaturating the drywall, which can cause damage. Alternatively, use a spray bottle to mist the area.
3. Let it sit: Allow the water to soak into the paste for 5-10 minutes. This rehydrates it, making it easier to remove.
4. Scrape and wipe: Use a clean, damp sponge or a microfiber cloth to wipe away the softened paste. If needed, a plastic putty knife or a paint scraper held at a very low angle (almost flat against the wall) can help lift thicker globs. Be extremely careful not to gouge the drywall.
5. Rinse: Wipe the area with a clean sponge dipped in plain warm water to remove any remaining soap or vinegar residue.
6. Dry: Let the wall air dry completely.
7. Repeat if necessary: For stubborn spots, you may need to repeat the process.

Method 2: Sugar soap or TSP substitute

For more stubborn, dried-on paste, a stronger cleaner is necessary.

1. Safety first: Always wear gloves and eye protection when working with sugar soap or TSP substitutes. Ensure good ventilation.
2. Mix the cleaner: Follow the manufacturer’s instructions for mixing sugar soap or a TSP substitute with warm water. A common ratio for sugar soap is about 1/2 cup per gallon of water.
3. Apply the solution: Using a sponge or a spray bottle, apply the cleaning solution to the paste residue.
4. Let it work: Allow the solution to sit for a few minutes to break down the paste.
5. Scrub gently: Use a sponge or a soft-bristled brush to gently scrub the area. A plastic scraper can be used carefully on thick deposits.
6. Rinse thoroughly: This is crucial. Use a clean sponge dipped in fresh water to rinse the wall multiple times, ensuring all cleaner residue is removed. Leftover cleaner can interfere with paint adhesion.
7. Dry completely: Allow the wall to dry thoroughly before proceeding.

Method 3: Wallpaper steamer

If you have a large area or very old, stubborn paste, a wallpaper steamer can be a lifesaver. This method is particularly effective for removing the wallpaper itself, but it also softens paste for easier removal.

1. Prepare the area: Cover the floor with a drop cloth to catch dripping water and paste.
2. Steam the wall: Hold the steamer plate against the wall for the recommended time (usually 30-60 seconds per section). The steam penetrates the wallpaper and loosens the paste.
3. Scrape and wipe: As you steam, use a putty knife or scraper to gently lift the wallpaper and softened paste. Follow up with a sponge and warm water to remove any remaining residue.
4. Rinse and dry: As with other methods, rinse the wall with clean water and let it dry completely.

When to use caution with a steamer

Be mindful of how long you steam any single area. Excessive steam can damage drywall paper, especially if it’s already weakened. It can also soften the adhesive holding the drywall to the studs. Work in sections and avoid prolonged steaming.

Dealing with specific paste types

Pre-pasted wallpaper: This paste is usually thin and designed to be water-activated. Warm water and a sponge are often sufficient. The goal is to reactivate the glue so it can be wiped away.

Strippable wallpaper: While the top layer is designed to peel off, the adhesive often remains. You’ll likely need warm water or a cleaning solution to remove the paste residue.

Non-strippable wallpaper: This type requires a chemical stripper or a steamer to remove the paper itself, and you’ll almost certainly have paste residue to deal with afterward.

Tips for success and avoiding common mistakes

• Test in an inconspicuous area: Before attacking the whole wall, test your chosen method in a corner or behind a piece of furniture to ensure it doesn’t damage the wall surface.
• Don’t overwet the drywall: Excessive moisture can cause drywall to swell, bubble, or even crumble. Work in manageable sections and use damp, not soaking wet, sponges.
• Use the right tools: A plastic scraper is safer for drywall than a metal one. If using a metal scraper, keep the angle extremely low and apply minimal pressure.
• Rinse, rinse, rinse: This cannot be stressed enough. Residual paste or cleaning solution will affect your next step, whether it’s painting or applying wallpaper liner.
• Allow for complete drying: Rushing the drying process can lead to mold or mildew issues, especially in humid climates. Ensure the walls are bone dry before applying new finishes.
• Consider primer: Once the walls are clean and dry, applying a high-quality primer is essential. It seals the surface, covers any faint remaining marks, and ensures a uniform finish for your new paint or wallpaper. For particularly stubborn residue or if you’re concerned about adhesion, a stain-blocking primer is a good choice.

Removing wallpaper paste might seem like a tedious chore, but it’s a crucial step for achieving a beautiful, lasting finish. By understanding the properties of the paste and using the right techniques, you can ensure your walls are perfectly prepped for their next transformation, whether it’s a fresh coat of paint or a new pattern like damask wallpaper or even paintable wallpaper.