Paint isn't the cause and it isn't the cure.
Most Brisbane homeowners think of mould as a paint problem. It isn't. Mould grows where there's moisture, organic material, and warmth. Brisbane has all three in abundance. Paint can slow mould down, but it can't fix the underlying moisture issue. Painting over mould without addressing the cause is a 6-month fix at best.
Diagnose first.
Before we talk about paint, identify where the moisture is coming from. Common Brisbane sources:
- External leaks: failed flashings, blocked gutters, rendered walls cracking at the parapet.
- Plumbing leaks: slow leaks under sinks, behind bathroom walls, in laundry walls.
- Condensation: warm humid air hitting cold surfaces (often south-facing exterior walls or poorly-ventilated bathrooms).
- Ground moisture: rising damp on older homes without proper damp courses.
- Air-con drainage: split-system condensate lines leaking inside walls.
Treat the source. Then paint.
Prep that actually addresses mould.
Once the moisture source is dealt with, the prep regime:
- Mould-kill wash: a 5% bleach solution or a proper biocide cleaner (Concrobium or similar). Wear PPE.
- Wait 24 hours: let the biocide do its work, let the wall dry.
- Light sand: remove any loose paint, get back to a sound substrate.
- Stain-block primer if there's discolouration that bleeds through.
- Anti-microbial primer: adds a second layer of mould defence under the topcoat.
If you skip the mould-kill wash and just paint over, the mould reactivates under the new paint within months.
Topcoat options.
For wet areas (bathrooms, laundries, kitchens) or persistently mould-prone walls:
- Dulux Wash & Wear Anti-Microbial: premium acrylic with a built-in anti-microbial agent.
- Haymes Anti-Microbial: similar system, slightly stronger on some substrates.
- Resene Lustacryl Kitchen & Bathroom: semi-gloss with anti-microbial properties; good for walls that get cleaned often.
For external mould-prone walls:
- Dulux Weathershield with a mould-inhibitor additive.
- Sample lighter colours: they reflect more heat and dry faster than dark colours.
Anti-microbial isn't a free pass.
Anti-microbial paint systems reduce mould pressure but don't make a wall waterproof. They're one part of a system that also requires:
- Source moisture control.
- Adequate ventilation (exhaust fans in bathrooms, kitchen extractors used).
- Sunlight where possible (mould doesn't like UV).
- Regular cleaning: wipe down condensation, check corners of bathrooms, treat any new spotting fast.
The Brisbane-specific habits.
- Run bathroom exhausts for at least 15 minutes after showers.
- Open windows on dry days to drop indoor humidity. Brisbane's autumn and winter are surprisingly dry, so use them.
- Don't seal homes air-tight unless you have an active dehumidifier or ducted air-con drying the air.
- Trim back trees and shrubs that shade external walls. Denser shade means slower drying.
- Check gutters before storm season: overflows cascade water down walls and into substrates.
When mould is the painter's job.
We address mould as part of any interior or exterior repaint where it's evident. The mould-kill wash and anti-microbial spec is part of our standard interior process for bathrooms, kitchens, and laundries. Exterior mould gets addressed during prep.
We don't claim to be moisture diagnosticians, though. If we suspect a structural moisture issue, we'll flag it and recommend you get a building inspector or roofer involved first. Painting over a moisture issue is wasted money.
Want a repaint that includes proper mould treatment? See our interior painting or exterior painting services. Or get a quote.