Wallpaper installation: A step-by-step guide

Preparing the walls for wallpaper installation: Can you skip it? If you're planning to redecorate with new wallpaper, preparing the surface is absolutely essential. Just as with laying flooring, the wall must be properly prepared to achieve the best possible result. In theory, you can apply new wallpaper to almost any surface. However, for a flawless and long-lasting finish, it’s well worth taking the time to properly prepare the wall.

In this article, we explain how to prepare your walls for wallpaper installation. We outline the key steps and share practical tips and tricks to help you achieve a smooth and professional result.

Why is it important to prepare the wall before wallpapering?

Technically, you don't have to prepare your walls before wallpapering. However, thorough surface preparation can greatly improve both the appearance and the durability of your wallpaper.

While it may seem like a tedious step, preparing the wall is highly recommended—especially if the surface is damaged or doesn’t absorb adhesive properly. Wallpaper paste works best on surfaces that are neither too absorbent nor completely resistant, allowing the adhesive to bond effectively. Any imperfections or cracks may become visible beneath the wallpaper, whether you’re using a classic floral wallpaper or a modern striped non-woven wallpaper design. It goes without saying that flaky or cracked walls are not a suitable base for wallpapering.

Just like with flooring, the rule applies: the wall should be Structurally sound, Even, Clean, and Dry. In addition, it’s important to check how absorbent the wall is. You should consider surface repairs in the following cases:

• Uneven walls
• Cracks or fissures
• Poor or excessive absorbency
• Damp or moist areas
• Dirt or dust buildup

What type of surface is suitable for wallpapering?

Walls aren’t always perfectly smooth, clean, or ideally absorbent. Whether or not your wall needs preparation before wallpapering largely depends on the condition and type of surface. In rented flats or during renovations, you’ll often find typical substrates like paintable wallpaper (such as woodchip) or emulsion-based wall paints. Here’s what to keep in mind for each type of surface:

1. Should you remove old wallpaper?

Technically, no—you don’t always need to remove the old wallpaper if you plan to wallpaper over it. However, it’s strongly recommended. Depending on the existing surface, the new wallpaper might not stick properly, seams may not align edge-to-edge, bubbles or creases could form, and old patterns—especially brightly coloured wallpapers—might show through.

Non-woven wallpapers are usually easy to remove dry and in full strips. Paper wallpapers, on the other hand, often need to be perforated and slightly moistened before being carefully scraped off with a spatula, bit by bit.

Non-woven wallpapers are significantly easier to remove than traditional paper-backed wallpapers, which usually require perforating and soaking with water before they can be peeled off. For especially stubborn wallpaper, you can use a liquid wallpaper remover, which helps to loosen the adhesive and makes the removal process much easier.

2. Can you wallpaper over painted walls?

If you want to prepare your walls before wallpaper installation, it’s important to consider the existing paint layers. Ideally, old, loose, or cracked paint and varnish layers should be removed before wallpapering. This can be achieved by sanding or scraping the surface. For stubborn residues, paint stripper or chemical paint removers might be necessary.

Most rental properties have wall paints in their homes. Scrubbable emulsion paints can be softened and removed using a mixture of water and wallpaper remover. For older glue-based paints, the wall should be thoroughly washed with water, possibly aided by a wallpaper remover. After cleaning, it’s advisable to apply a water-based primer to improve the wall’s absorbency.

If the wall has oil-based paints or varnishes, it’s best to apply a lining paper (also known as ‘renovation fleece’) with dispersion adhesive before wallpapering.

3. Mineral surfaces: plasterboard, concrete, and render

For mineral substrates such as plaster, plasterboard, concrete or gypsum-based fillers, it is advisable to pre-treat the surface with diluted paste. To ensure even absorbency, you should also apply a wallpaper primer to the substrate.

Preparing the wall for wallpapering: The standard steps

1. Remove old coverings: Check whether old paint or wallpaper needs to be removed.
2. Fill walls: Cracks, holes, and larger uneven areas should be filled and smoothed with filler.
3. Sand walls: After the filler has dried, sand the wall. For smaller areas, hand sanding with grit between 120 and 180 is usually sufficient.
4. Clean walls: Remove any sanding dust, cobwebs, and dirt.
5. Apply wallpaper primer: Apply a wallpaper primer to improve the wall’s absorbency.
6. Allow the wall to dry: Let the primer dry for at least 24 hours before starting to wallpaper.

Load-bearing capacity: preparing the wall for wallpapering

If the substrate flakes or the plaster or chalk dust crumbles away, the wallpapering result can be affected. There’s even a risk that the entire wallpaper strip will peel off the wall. Immediate action is needed in such cases: inspect the walls and apply some pressure. If the surface feels soft, repairs are necessary. You can also use sticky tape: if paint or plaster residues stick to the tape when removed, it indicates the old coating should be removed. For chalky or sandy plasters, there are special primers designed specifically for “old plaster” to improve adhesion before wallpapering.

Rough times? Smooth those walls!

To properly prepare your wall for wallpapering, you should definitely check its surface condition. Whether it’s a colourful retro wallpaper or a subtle country-style wallpaper, rough and dusty walls can worsen the wallpapering result. Especially the overall look can be affected by uneven surfaces. Use a torch or work light to inspect how smooth the wall really is. If needed, fill any imperfections and consider applying a lining paper for a flawless finish.

Preparing the wall for wallpapering and filling cracks

Cracks in the walls can also negatively affect the wallpapering result. To prepare the wall for wallpapering, it is advisable to use a lining paper to bridge smaller cracks such as hairline cracks, spiderweb cracks, shrinkage cracks, or joint cracks. The lining paper helps to cover these imperfections. However, caution: for expansion cracks and structural cracks, more extensive construction repairs are recommended!

Depending on the condition of the wall, it can be plastered either spot-wise or over larger areas. For minor repairs, ready-mixed filler is often sufficient.

Why wall absorbency is essential for wallpapering

When preparing the substrate, absorbency is just as crucial as flatness. Whether it’s a plain wallpaper or a wall mural, wallpaper adheres perfectly only if the substrate is neither too absorbent nor not absorbent enough. If the substrate is not absorbent enough, the paste will not stick well, and the wallpaper may peel away from the wall.

On the other hand, if the substrate is too absorbent, the paste is absorbed too quickly, causing high surface tension. This can lead to bubbling and visible seams, especially in the joint areas. A common example of an overly absorbent substrate is plasterboard.

Is my wall sufficiently absorbent?

If you want to prepare the wall before wallpapering, you first need to determine whether the substrate is sufficiently absorbent. To test this, moisten the wall with some water.

• The water beads up: the wall is little or not absorbent. In this case, it is advisable to apply a lining paper (or renovation fleece).
• The water is absorbed quickly: the wall is too absorbent. It’s best to apply a wallpaper primer.

Wallpaper primer is available ready to use. You can apply it with a brush, roller, or ceiling brush.

Sinter layers impair the absorbency of the substrate

When preparing the wall for wallpapering, you should also watch out for so-called sinter layers. These usually form during drying as binder deposits on screeds or plaster. They can often be identified by a slight sheen. To be sure, you can scratch the wall lightly and moisten it with water. If the wet scratches darken, it’s very likely a sinter layer. Since these layers are hardly absorbent, they should be sanded off before wallpapering.

Colour-neutralising the substrate for translucent wallpapers

If you’ve chosen a white wallpaper or another translucent type, it’s advisable to colour-neutralise the substrate. In this case, when preparing the wall for wallpapering, it’s best to use a white wallpaper primer. Conversely, for black wallpapers or other dark-coloured wallpapers, sometimes a dark primer is applied to the substrate so that the white wall does not show through brightly at the seams.

If the substrate is dark and blotchy, it may be worth applying a white primer before hanging the Circus Wallpaper Nursery, number 771481.

Damp substrate: what to do?

Generally, it’s not a good idea to wallpaper on a damp substrate. If you wallpaper on a damp wall, the seams can open up or the wallpaper may peel off entirely. Usually, you are informed about any moisture in the walls, but you can also check with a moisture meter whether the walls are damp. Alternatively, you can place a plastic sheet against the wall; if condensation forms behind the sheet, the wall is unsuitable for wallpapering. The cause of the moisture must be resolved and the walls thoroughly dried before any work is done. For example, do not wallpaper if salt deposits are visible on the wall, as this indicates moisture in the masonry.

If mould appears on the wall, wallpapering is also not recommended. Here, the cause must be eliminated and the mould removed. After wallpapering, it’s important to ventilate and heat the room regularly to prevent fungal growth.

These walls should definitely not be wallpapered: the cause of the moisture must be addressed first.

Conclusion

Preparing the wall before wallpapering is not mandatory, but it improves the final result and ensures a perfect finish, especially in the long term. Depending on the substrate, different measures may be required. Standard preparations include removing old wallpaper, repairing cracks, holes or unevenness, sanding, and cleaning the wall. We recommend applying a wallpaper primer to ensure optimal adhesion. Damp, painted, or structurally damaged walls should not be wallpapered. Using a lining paper creates a perfect, clean, and smooth base for your new pattern wallpaper.

We hope this guide has helped you prepare your walls. Find the perfect wallpaper for your makeover at BRICOFLOR, the expert for walls & floors!