Q: What do I need to apply to wallpaper that I’m going to paint over?

If the wallpaper is already painted, the first step is to clean it down using a mild soapy water solution and a soft cloth. Be sure to let the surface dry thoroughly before you start and avoid using any abrasive cleaning products as they can damage the wallpaper surface and reduce adhesion.
If the wallpaper is vinyl, painting directly over it with standard paint can lead to issues. That’s because plasticisers in the vinyl may leach through the topcoat, leaving it tacky or soft. To get a proper finish, it’s important to seal the wallpaper with a specialist product before painting.

Here’s what the experts recommend:

• For vinyl wallpaper, apply one coat of Vinyl Wallpaper Sealer first, followed by two coats of Resene SpaceCote Low Sheen.
• For non-vinyl wallpaper, you can apply Resene SpaceCote Low Sheen directly in two coats, no sealer needed.

If you’re unsure whether the wallpaper is vinyl or not, try testing a small hidden patch first, or ask one of our team members in-store for guidance. Keep in mind that painting over wallpaper is a temporary solution in most cases. If you’re after a long-term finish, removing the wallpaper and prepping the wall underneath is always going to give the best result.

Stripping back to wood

What’s the fastest way to remove paint from timber surfaces?

Removing old paint from wood is one of those jobs where having the right product makes a big difference. If you’re repainting a timber surface like a door, window frame or piece of furniture, a paint stripper is typically the fastest option. There are a few different types of paint strippers on the market, and they each work slightly differently depending on the surface and number of paint layers you're dealing with. Some gel-based products are ideal for vertical surfaces, while others are stronger and better suited to thicker paint removal.

Safety reminder:

If you are stripping back older paint, it is important to check whether the surface has previously been painted with lead based paint. Lead paint was commonly used in homes built before the 1970s and requires extra care when removing.
We sell easy to use lead paint testing kits that allow you to check your surface before you start. If lead is present, our team can help you choose safer removal methods and the right protective equipment.

Before you begin, make sure to:

• Test for lead based paint
• Read and follow the safety instructions carefully
• Work in a well-ventilated area
• Wear protective gear like gloves and eye protection
• Lay down a drop sheet to protect nearby surfaces

Once the paint stripper is applied, you’ll need to wait for it to work before scraping it off using a paint scraper or similar tool. It’s usually best to work in sections and take your time to avoid damaging the wood underneath. After stripping, sand the surface lightly to prep it for repainting.
If you’re working on small sections like trims or frames, heat guns or sanding can also be used, just be cautious, especially with older painted surfaces that may contain lead.

Bubbles and blistering

Q: Why are bubbles appearing on my weatherboards after painting?

This is a common issue that typically comes down to surface preparation and not necessarily the paint itself. Bubbles (also known as blistering) form when there’s poor adhesion between the surface and the paint. They trap air or moisture under the surface and can lead to cracking or peeling if not addressed.

Here’s what could be causing it:

• Poor surface prep: If the surface wasn’t cleaned properly before painting, for example, if sanding dust was left behind, it creates a barrier between the paint and the timber.
• Painting over damp surfaces: Moisture in the timber or in the air during painting can cause bubbling as the paint tries to dry.
• Missing or incorrect primer: Bare timber or previously damaged surfaces need to be properly primed. Skipping this step or using the wrong primer increases the chance of adhesion failure.
• Sap bleed: Some timbers (like pine) contain natural sap or tannins that can push through paint layers and cause bubbling or discolouration, especially if darker colours are used which absorb more heat.

How to fix it:

• Scrape off any bubbling or flaking paint with a scraper or wire brush.
• Sand back the affected area to smooth the edges and remove any residue.
• Prime the bare surface using a suitable sealer or primer recommended for your timber type.
• Repaint using a high-quality exterior paint, ideally in a lighter colour if sap bleed is a concern.

Painting on plaster walls

Q: How do I paint on plaster for a long-lasting finish?

Getting a professional-looking, durable result on plaster walls starts with proper prep and every step matters. Whether you're working with new plaster or repainting older surfaces, how you prepare the surface will directly impact how well your paint holds up over time, especially in rooms exposed to moisture or temperature fluctuations.

Step 1: Repair and clean Start by inspecting the plaster surface carefully. Look for any hairline cracks, flaky areas, dents, or old paint that may be lifting. These should be filled with a suitable filler and sanded smooth once dry. Dust off any sanding residue, and wash the walls with sugar soap or a mild detergent solution to remove grease, dust, and contaminants. Then allow the surface to dry fully.

Helpful tip:

If there’s any sign of old water staining or damp patches, make sure the underlying cause is resolved before you continue. Applying paint over moisture can lead to blistering or mould problems later on.

Step 2: Prime the surface Bare plaster is highly porous and will absorb paint unevenly if not sealed first. That’s why priming is crucial, it locks down the surface and ensures your top coats stick properly, with even coverage and colour depth.

• Resene Sureseal is a specialist pigmented sealer designed for new or repaired plaster surfaces. It penetrates into the plaster, hardens it, and prevents patchiness, making it ideal for use before top coating.
• For older or previously painted plaster, a general-purpose sealer may suffice, you can always ask a team member in-store to help assess your wall condition and get personalized advice.

Step 3: Apply your topcoats Once primed and fully dry, you’re ready to paint. Two coats of a high-quality, water-resistant acrylic paint will help ensure long-lasting durability, especially in high-moisture areas like bathrooms or kitchens.

• Resene X-200 is a flexible, breathable acrylic membrane designed to resist cracking and moisture, while traditionally used on exteriors, it’s also suitable in high-moisture interior spaces that need extra protection.li>
• Alternatively, choose a top-quality interior wall paint with mould resistance built-in, like Resene SpaceCote Low Sheen.

Want a smooth finish?

Use a 10–12mm roller nap for most walls. Go smaller (6–8mm) for finer results on very smooth plaster or feature walls.