Painting over wallpaper is one of the most tempting shortcuts in home decorating. Stripping wallpaper is messy, time-consuming and sometimes damages the plaster underneath. But painting straight over it without the right preparation is how bubbling, peeling and visible seams happen within months. Done correctly, painting over wallpaper can produce a clean, lasting finish. Done badly, it creates a problem that's harder to fix than the one you started with.
When painting over wallpaper is actually a good idea
Not every wallpapered wall is a candidate for painting. The wallpaper needs to be firmly bonded across its entire surface. Run your hand across the wall and press lightly at the edges and seams. If the paper lifts anywhere, it won't survive a coat of paint. Water-based primers cause wallpaper adhesive to release, and once the paper starts peeling under paint, the only real fix is full removal.
Wallpaper in good condition on a solid plaster or plasterboard wall is a reasonable candidate. Wallpaper on top of other wallpaper is not. Multiple layers trap moisture and move independently of each other, and paint makes that movement visible. If you can see a seam between layers at any corner or edge, strip both layers before proceeding.
Textured wallpaper deserves its own assessment. Light texture can look intentional once painted. Heavy embossed patterns will telegraph through even two coats of quality paint and often look worse painted than papered.
Preparation: the step that decides everything
Clean the entire surface with a mild sugar soap solution and a damp cloth. Grease, dust and old grime all prevent adhesion. Let the wall dry completely before touching it with primer or paint. This matters more than most people expect.
Next, address the seams. Every seam is a potential failure point. Press each one flat and apply a thin bead of seam repair adhesive along any that feel loose. Wipe off the excess and let it cure fully. Sand proud seams lightly with 120-grit sandpaper until they sit flush. Rushing this step is the single biggest reason painted wallpaper looks bad.
Fill any torn sections of the paper's surface with lightweight filler, feathered out at the edges. Sand smooth when dry. A few minutes spent here prevents the filled spots from telegraphing through the finished coat.
If you're working with a previously painted surface elsewhere in the room, the prep logic is identical: adhesion depends entirely on what you do before you open the tin.
Priming: don't skip it and don't use the wrong type
This is where most DIY attempts go wrong. Standard water-based primers cause the wallpaper to absorb moisture unevenly, which lifts the paper from the wall before the primer even dries. Use an oil-based primer or a shellac-based primer instead. Both seal the paper without wetting it, and they dry quickly enough that you can coat the same day.
Apply the primer with a low-nap roller. Don't saturate the paper. A thin, even coat is what you're after, not full coverage in a single pass. Let it dry completely. Oil-based primers typically need 4 to 6 hours in Melbourne's climate before they're ready for top coat. Shellac-based primers can be dry in under an hour.
Once primed, stand back and look at the wall in raking light. A torch held at a low angle works well. Any seams, bubbles or surface inconsistencies will be visible now and can be addressed before paint goes on. Fix them with lightweight filler, sand smooth and spot-prime. It's far easier at this stage than after top coat.
Choosing and applying the top coat
A low-sheen or flat acrylic finish suits most papered walls. Higher sheens catch the light and make every surface imperfection visible. If you're painting a hallway or a room that needs occasional wiping, a low-sheen acrylic is washable enough without broadcasting the texture of the paper underneath.
Apply the top coat in two thin passes rather than one thick one. Thick coats trap solvent and increase the chance of bubbling. Work in sections and maintain a wet edge to avoid lap marks. If you've never dealt with lap marks on a ceiling before, the principles in our guide to painting a hallway ceiling without streaks apply equally here. Keep the roller speed consistent and don't overwork any section.
Two coats is the minimum. Three is better on a textured or heavily seamed surface. Let each coat dry fully before the next. Rushing the recoat on a papered wall risks softening the primer layer and lifting the paper.
What to do if bubbles appear
Small bubbles during the wet coat often disappear as the paint dries. Don't touch them. If a bubble is still present after the coat has fully dried, the wallpaper adhesive has released in that spot. Let the paint cure for 24 hours, then press the bubble gently. If it re-adheres, apply a light second coat over the top. If it doesn't, carefully slit the bubble with a sharp blade, inject a small amount of wallpaper adhesive, press flat and allow it to dry before spot-priming and repainting.
Persistent bubbling across multiple areas usually means the primer was applied too wet or the wallpaper wasn't firmly bonded to begin with. At that point, stripping and replastering is the more reliable path. Dulux and other major paint manufacturers publish technical data sheets for their primers that specify application weights and dry times. Following those figures prevents most primer-related failures.
When removal is the better call
Wallpaper removal isn't always the disaster people fear. Modern scoring tools and wallpaper removal solutions have improved considerably, and on a well-plastered wall, removal leaves a surface that paints cleanly with no hidden risk of future lifting. If the wallpaper is old, layered, damp in any section, or covering a surface you can't inspect, removal is worth the extra day's work. Painting over a problem you haven't diagnosed is how a weekend job becomes a month of repairs.
If the underlying plaster is in poor condition after stripping, that's a separate repair job before any paint goes on. Understanding how to handle paint failure on rendered or patched walls will help you work through the sequence correctly before picking up a brush.
Apex Painting handles wallpaper preparation and painting across Melbourne for homeowners who want the job done once and done well. Correct preparation is the whole job. Everything after that is just paint.