If you've spotted dark patches creeping across your bathroom ceiling or caught a musty smell you just can't place, you're far from alone. The last national survey found mould or mildew in almost 1 in 5 Australian homes — and closer to 1 in 4 rentals. For busy families, finding the time and energy to deal with it can feel like one more thing on an already overflowing plate.
Quick Answer: To remove mould safely, wear protective gear (P2 mask, gloves, goggles), ventilate the area, then clean non-porous surfaces with white vinegar or a commercial mould remover like Selleys Rapid Mould Killer. For porous surfaces like drywall, vacuum with a HEPA filter first, then gently scrub. Always address the moisture source — without fixing ventilation or leaks, mould will return.
Why Mould Matters More Than You Think
Mould is a type of fungus that reproduces by releasing tiny spores into the air. These spores are invisible, and when you breathe them in, they can cause real health problems — especially for children and anyone with existing respiratory conditions.
NSW Health warns that people with asthma, allergies, or weakened immune systems are most at risk. Symptoms include sneezing, coughing, wheezing, skin irritation, and in serious cases, respiratory infections.
Beyond health, mould causes structural damage. It feeds on organic materials like wood, plaster, and insulation — slowly breaking them down over time. CSIRO research estimates that eradicating indoor mould in Australia could save $2.82 billion in health costs over 20 years.
What Causes Mould in Australian Homes?
Mould needs just two things to thrive: moisture and a surface to grow on. In Australian homes, the most common moisture sources are:
Condensation — warm, humid air hitting cold surfaces like windows and exterior walls
Poor ventilation — bathrooms, laundries, and kitchens without exhaust fans
Water leaks — under sinks, around pipes, through roofs
Drying clothes indoors — a surprisingly common contributor
Common Mould Hotspots
Bathroom ceilings and tile grout
Behind wardrobes pushed against exterior walls
Laundry rooms and basements
Around air conditioner condensers
Under kitchen sinks
Window frames and sills
Even in drier cities like Adelaide and Perth, indoor condensation and poor ventilation create the conditions mould needs. It's not just a subtropical problem.
How to Identify Mould in Your Home
The most obvious sign is dark patches on walls, ceilings, or grout. Black mould (Stachybotrys) is the best-known type, but mould can also appear green, white, brown, or orange.
Other signs to watch for:
A persistent musty smell, even after cleaning
Peeling or bubbling paint
Small bulges in walls or ceilings
Allergic symptoms that improve when you leave the house
If you can smell mould but can't see it, check behind furniture, inside built-in wardrobes, and under sinks. Mould often grows in hidden spots long before it becomes visible.
Safety First — Before You Start Cleaning
⚠️ Safety note: People with asthma, weakened immune systems, pregnant women, and young children should not remove mould or be present during the cleaning process. — Better Health Victoria
Before you begin, gather your protective equipment:
P2 face mask (available at Bunnings or Chemist Warehouse — cloth masks won't filter spores)
Rubber gloves
Safety goggles
Old long-sleeved clothing you can wash separately afterward
Open windows and doors for ventilation. Turn on exhaust fans. Never dry-brush mould — always dampen it first to keep spores from becoming airborne.
⚠️ Safety note: Never mix bleach with vinegar or ammonia — the combination produces toxic gases. Use one method or the other, never both. — NSW Health
How to Remove Mould From Different Surfaces
The right method depends entirely on what the mould is growing on. If your problem is specifically on painted walls or a bathroom ceiling, our step-by-step guide to removing mould from walls and ceilings covers those two surfaces in far more detail.
Painted Walls and Ceilings
DIY cleaning solution: Mix 2 cups of hot water, ¼ cup white vinegar, and 2 tablespoons of borax. Stir until dissolved, then transfer to a spray bottle.
Clear the area and lay drop cloths on the floor
Spray the solution directly onto the mould — this kills spores and prevents them from becoming airborne
Wipe with a damp sponge, moving in one direction (top to bottom)
Inspect and repeat if needed
Wipe clean with a fresh damp cloth to remove residue
Blot dry and ventilate the room until the surface is completely dry
Tip: Be gentle on walls that have been damp for a long time — the paint finish may already be compromised.
Drywall
Drywall is porous, which means mould can grow into the material itself. This makes it harder to remove completely.
Use a HEPA-filter vacuum to remove surface mould and embedded spores — standard vacuums blow spores back into the air
Apply a commercial mould remover designed for porous surfaces, or use the vinegar-borax solution above — scrub gently with a soft brush in circular motions
Blot with paper towels to absorb moisture quickly
Wipe with a sanitising wipe to catch remaining spores
Dry thoroughly — point a fan directly at the wall and keep windows open
Bathroom Tiles and Grout
Bathrooms are mould's favourite room. Grout lines and silicone seals are the most common trouble spots.
For tiles, spray with undiluted white vinegar or a commercial product like Selleys Rapid Mould Killer (available at Bunnings, Coles, and Woolworths). Leave for 10–15 minutes, then scrub with an old toothbrush.
For silicone seals with deep mould staining, replacement is often the most effective option. New silicone costs under $15 at Bunnings and takes about 20 minutes to apply.
For more bathroom-specific tips, check out our bathroom cleaning tips.
Unfinished Concrete
Garages, basements, and laundry floors often have unfinished concrete where mould thrives in damp conditions.
Cleaning solution: Mix equal parts water and household ammonia with a squirt of liquid dish soap. Start with a weaker mix and increase strength if needed.
Wet the concrete with plain water first to prevent airborne spores
Scrub with a stiff-bristled brush dipped in the solution — it should foam as you work
Leave for 30 minutes, then inspect for remaining dark patches
Rinse with clean water (hose for floors, wet brush for walls)
Ventilate and dry thoroughly
Natural vs Commercial Mould Removers
You might have tried bleach and found the mould coming right back within weeks. You're not imagining it. CHOICE Australia's testing confirms that bleach only kills surface mould on non-porous materials — it can't penetrate grout or drywall the way vinegar can.
Method | Best For | Pros | Cons |
|---|---|---|---|
White vinegar | Non-porous surfaces, mild mould | Natural, safe around children, penetrates porous surfaces | Less effective on severe infestations |
Commercial sprays (Selleys, 30 Seconds) | Bathroom tiles, grout, silicone | Fast-acting, effective on tough mould | Chemical fumes, keep children and pets away |
Clove oil (diluted) | Surfaces needing longer-lasting protection | Kills mould and helps prevent regrowth | Can stain light surfaces; may irritate asthmatics |
Bicarb soda paste | Delicate surfaces, light mould | Non-toxic, mildly abrasive | Less effective on established mould |
How to Prevent Mould From Coming Back
Removing mould is only half the job. Without addressing the underlying moisture, it will return — often within weeks. Here's how to keep it away for good:
Ventilate — run exhaust fans during and for 15 minutes after showering or cooking
Open windows when weather permits, especially in bedrooms and laundries
Use a dehumidifier in rooms without good airflow (available at Bunnings, Harvey Norman, The Good Guys)
Squeegee shower screens and tiles after each use
Avoid drying clothes indoors without ventilation — hang outside or use a dryer
Fix leaks promptly — check pipes under sinks and around showers regularly
Pull furniture away from exterior walls — leave a 5–10 cm gap for air circulation
Use moisture absorbers (like DampRid) in wardrobes and enclosed spaces
Consider anti-mould paint (like Dulux Kitchen & Bathroom) when repainting damp-prone rooms
For more on keeping your bathroom fresh between deep cleans, see our guide on how hard water affects your home.
When to Call a Professional
Not all mould problems can be tackled with vinegar and elbow grease. The Australasian Society of Building Biologists recommends that mould must be physically removed — not just killed — following professional remediation guidelines.
Call a professional if:
Mould covers more than 1 square metre
It keeps returning despite your best efforts
You can smell mould but can't find the source
Anyone in your household has persistent respiratory symptoms
The mould is behind walls, under floors, or in your HVAC system
Professional mould remediation in Australia typically costs $500–$2,000+ per room, depending on severity. For surface-level mould in bathrooms and kitchens, a regular deep clean from a professional cleaning service can help keep things under control before it becomes a bigger problem.
Frequently Asked Questions
Q: Does vinegar kill mould?
Yes. White vinegar kills many common household mould species. Spray undiluted white vinegar onto the mould, leave for at least an hour, then wipe clean. For severe or deep mould, you may need a commercial product or professional help.
Q: Is bleach or vinegar better for removing mould?
Vinegar is generally better for household mould. Bleach only kills surface mould and doesn't penetrate porous materials like grout or drywall. Vinegar can reach deeper into porous surfaces. Never mix bleach and vinegar together — it produces toxic chlorine gas.
Q: How do I know if mould in my home is dangerous?
All indoor mould should be removed, regardless of type. If anyone in your household develops persistent coughing, wheezing, or skin irritation that improves when they leave the house, see a GP and address the mould promptly. Children and people with asthma are at higher risk.
Q: Who is responsible for mould in a rental property?
In most Australian states, landlords are responsible for structural issues that cause mould (leaks, inadequate ventilation). Tenants are responsible for reasonable care — ventilating after showers, reporting leaks promptly. Document the mould with photos and report it to your landlord or property manager in writing.
Q: Can you paint over mould to stop it?
No. Painting over mould without removing it first won't work — the mould will grow through the new paint within months. Remove all visible mould completely, allow the surface to dry, then apply an anti-mould primer before repainting.
