Sizing a wall for wallpaper involves applying a special solution that prepares the surface to properly receive the wallpaper, ensuring better adhesion and preventing damage. Here's how to do it:
1. Understanding Wall Sizing
Wall sizing, also called wallpaper size or primer, is a liquid treatment applied to walls before wallpapering. It serves several critical purposes:
- Seals the Wall: It reduces the wall's porosity, preventing it from absorbing too much moisture from the wallpaper paste. This ensures the paste stays wet long enough to allow proper adhesion.
- Improves Adhesion: It creates a slightly tacky surface that allows the wallpaper to grip the wall more effectively.
- Makes Removal Easier: It creates a barrier between the wall and the wallpaper, making future wallpaper removal less damaging to the wall.
- Prevents Staining: It seals in any existing stains or imperfections, preventing them from bleeding through the wallpaper.
2. Preparing the Wall
- Clean the Wall: Remove any dust, dirt, grease, or loose paint. Wash the wall with a mild detergent solution and rinse thoroughly.
- Repair Imperfections: Fill any holes or cracks with spackle or joint compound. Sand the repaired areas smooth.
- Remove Old Wallpaper: If there is existing wallpaper, remove it completely. Any remaining adhesive can interfere with the sizing.
3. Choosing the Right Sizing
- Read the Wallpaper Instructions: Some wallpapers require specific types of sizing. Follow the manufacturer's recommendations.
- Consider the Wall Surface: Porous surfaces like new drywall or plaster require a heavier sizing. Non-porous surfaces like previously painted walls may require a lighter sizing.
- Types of Sizing: There are several types available, including:
- Clear Sizing: Suitable for most wallpaper types and surfaces.
- Pigmented Sizing: Contains pigment and can help cover stains or imperfections.
- Pre-Mixed Sizing: Convenient and easy to use.
- Concentrated Sizing: Needs to be diluted with water.
4. Mixing the Sizing Solution
- Follow the Manufacturer's Instructions: The proper mixing ratio is crucial for effective sizing. Typically, you'll use one part sizing solution to three parts water, but this can vary significantly.
- Mix Thoroughly: Ensure the solution is well mixed and free of lumps.
5. Applying the Sizing
- Tools: You'll need a paint roller, paint brush, or sponge; a paint tray; and a clean bucket for mixing.
- Apply Evenly: Dip a paint roller or sponge into the sizing solution and apply it evenly to the wall surface.
- Start at the Top: Begin at the top of the wall and work your way down in smooth, overlapping strokes.
- Avoid Drips: Be careful to avoid drips or runs, as these can create unevenness.
- One Coat is Usually Sufficient: Typically, one coat of sizing is enough. However, for very porous surfaces, you may need to apply a second coat after the first coat is completely dry.
- Allow to Dry Completely: Let the sizing dry completely before applying wallpaper. Drying time varies depending on the product and humidity, but typically takes several hours.
6. Checking for Tackiness
- Test Before Wallpapering: The sized wall should feel slightly tacky to the touch when dry. This indicates that the sizing has created a good surface for wallpaper adhesion.
By following these steps, you can properly size your walls for wallpaper and ensure a successful and long-lasting installation.
