How to Prepare Walls for Wallpaper
To prepare walls for wallpaper, start by removing any old wallpaper, repairing damage, cleaning the surface, and preparing the wall according to its material. Proper wall preparation creates a smooth, stable surface that helps wallpaper adhere evenly, reduces visible imperfections, and improves its long-term durability.
What You'll Need
Before you begin, gather the following tools and materials:
- Dust sheets
- Protective gloves
- Filling knife
- Wall filler
- Sandpaper (120 to 180 grit)
- Sugar soap or mild detergent
- Sponge and clean cloth
- Wallpaper scraper (if removing old wallpaper)
- Wallpaper steamer (optional)
- Wallpaper adhesive remover (if required)
- Wallpaper primer or sizing solution
- Vacuum cleaner or soft brush
Step-by-Step Guide
1. Remove Any Existing Wallpaper
If there is old wallpaper on the wall, remove it completely before installing new wallpaper.
Score the wallpaper if necessary, apply warm water or a wallpaper removal solution, and allow it to soak before carefully scraping it away. A wallpaper steamer can make removing old wallpaper easier, especially for multiple layers or stubborn wallpaper adhesive.
Take your time during wallpaper removal. Any leftover adhesive or paper can affect how well the new wallpaper bonds to the wall.
Tip: If you're wondering how to strip wallpaper without damaging the wall, avoid forcing the scraper. Let moisture soften the adhesive before scraping gently.
2. Remove Remaining Wallpaper Adhesive
Even after removing old wallpaper, adhesive residue often remains.
Wash the wall with warm water and a sponge or use a wallpaper adhesive remover if necessary. Sticky patches can prevent new wallpaper from sticking properly and may create visible bumps.
Run your hand over the surface after cleaning. The wall should feel smooth rather than tacky.
3. Repair Holes and Cracks
Inspect the wall carefully for:
- Nail holes
- Hairline cracks
- Chips
- Dents
Fill damaged areas with a suitable wall filler and allow it to dry completely. Once dry, sand the repaired areas until they are flush with the surrounding wall.
Skipping this step can cause imperfections to show through the finished wallpaper.
4. Sand the Entire Surface
Lightly sand the wall to remove rough patches, old paint drips, or uneven filler.
You do not need to remove all existing paint. The goal is simply to create an even surface that wallpaper adhesive can grip effectively.
After sanding, vacuum or wipe away all dust.
5. Clean the Walls Thoroughly
Dust, grease and dirt can weaken wallpaper adhesion.
Wash the walls with sugar soap or a mild detergent, then rinse with clean water if needed. Allow the walls to dry fully before continuing.
Never apply wallpaper to damp walls, as trapped moisture can cause peeling or mould.
6. Prepare Different Wall Surfaces
Different wall surfaces require slightly different preparation. Identifying your wall type before applying wallpaper will help you achieve a smoother finish and better adhesion.
Fresh plaster is highly porous and should never be wallpapered directly.
- Allow the plaster to dry completely.
- Apply a suitable plaster sealer or wallpaper primer.
- Let the primer dry before hanging wallpaper.
Sealing the surface prevents the plaster from absorbing too much wallpaper adhesive and makes future wallpaper removal much easier.
Painted Walls
Most painted walls are suitable for wallpaper if the paint is stable.
Before wallpapering:
- Wash away grease and dirt.
- Lightly sand glossy or satin finishes.
- Repair cracks or holes.
- Remove any loose or peeling paint.
If the paint is flaking or unstable, remove it before installing wallpaper.
Previously Wallpapered Walls
For the best finish, always remove existing wallpaper before applying new wallpaper.
Wallpapering over old wallpaper can cause visible seams, trapped air bubbles and poor adhesion, even if the original wallpaper appears secure.
Drywall or Plasterboard
New drywall should be fully finished before wallpapering.
Make sure:
- Joints have been filled and sanded smooth.
- Dust has been removed.
- The surface has been primed with a wallpaper primer.
This creates an even surface and helps the wallpaper adhere properly.
Textured Walls
Wallpaper performs best on smooth surfaces.
For lightly textured walls, sanding may be enough. Heavily textured finishes may require a skim coat before wallpaper installation.
Wallpaper applied over textured walls may show bumps, uneven seams and reduced adhesion.
Damp or Mould-Affected Walls
Never install wallpaper over damp walls or active mould.
First:
- Repair the source of the moisture.
- Remove any mould safely.
- Allow the wall to dry completely.
- Repair damaged plaster if necessary.
Wallpapering over damp surfaces often leads to peeling, staining and recurring mould growth.
Glossy or Oil-Based Painted Walls
Highly glossy finishes can prevent wallpaper adhesive from bonding properly.
Lightly sand the surface to create a key, then apply a wallpaper primer before installation.
7. Prime or Size the Walls
Once your wall has been cleaned and prepared for its specific surface type, apply a wallpaper primer or sizing solution if recommended.
Priming is especially beneficial for:
- Fresh plaster
- Newly repaired walls
- Highly porous surfaces
- Drywall or plasterboard
- Previously painted walls, particularly glossy finishes
Priming creates a more consistent surface, improves adhesion, and can make future wallpaper removal much easier.
Always allow the primer to dry according to the manufacturer's instructions before hanging wallpaper.
8. Check the Surface Before Hanging Wallpaper
Before opening your wallpaper rolls, inspect the wall one final time.
The surface should be:
- Clean
- Dry
- Smooth
- Dust-free
- Free from loose paint and wallpaper adhesive
Taking a few extra minutes now can help prevent bubbles, lifting edges and uneven seams later.
Common Mistakes to Avoid
Many wallpaper problems begin with poor wall preparation. Avoid these common mistakes:
- Hanging wallpaper over existing wallpaper.
- Leaving wallpaper adhesive residue on the wall.
- Filling holes but forgetting to sand them smooth.
- Applying wallpaper before the wall has fully dried.
- Ignoring grease, dust or dirt.
- Skipping primer on fresh plaster or highly absorbent walls.
- Wallpapering directly over textured walls without smoothing the surface.
- Hanging wallpaper over damp or mould-affected walls.
Good preparation often takes longer than hanging the wallpaper itself, but it produces a much better finish.
When to Call a Professional
Preparing walls is a manageable DIY task for many homeowners, but professional help may be worthwhile if:
- The walls have severe cracks or structural damage.
- Large areas of plaster are loose or crumbling.
- There is persistent damp or mould.
- Multiple layers of old wallpaper are extremely difficult to remove.
- Heavily textured walls require skimming before wallpaper installation.
A professional can repair the wall properly before wallpaper installation, helping to avoid future problems.
FAQ
Do I need to remove old wallpaper before installing new wallpaper?
Yes. Removing old wallpaper provides the best surface for new wallpaper. Hanging wallpaper over existing wallpaper increases the risk of bubbles, lifting seams and poor adhesion.
Should I wash the walls before wallpapering?
Yes. Cleaning removes dust, grease and residue that could prevent wallpaper adhesive from bonding properly.
Can I wallpaper over painted walls?
Yes, provided the paint is sound, clean and lightly sanded if glossy. Applying a wallpaper primer can further improve adhesion.
Do I need to prime fresh plaster before wallpapering?
Yes. Fresh plaster is highly absorbent and should always be sealed with a suitable primer or sizing solution before wallpaper is installed.
Can wallpaper be applied to textured walls?
It depends on the texture. Lightly textured walls can often be sanded smooth, while heavily textured walls usually need a skim coat before wallpapering to achieve the best finish.
Conclusion
Taking the time to prepare walls for wallpaper is one of the most important steps in achieving a neat, long-lasting result. By removing old wallpaper, cleaning away wallpaper adhesive, repairing imperfections and preparing the wall according to its surface type, you'll create the ideal foundation for installation.
Proper preparation not only makes wallpaper easier to hang but also helps premium and made-to-measure wallpaper sit smoothly, reducing the chance of bubbles, lifting edges and visible imperfections for years to come.
