In Wollongong and South Sydney, almost every house — we’re talking 90 to 100% — has mould in some shape or form. It’s what we call a slow poison. It might not kill you, but it’s not going to let you live your best life, either.
Most people don’t even realise they’ve got mould in their house. They just think the air feels a bit off, or they’re catching colds more often, but they don’t connect the dots. Meanwhile, it’s quietly working away, damaging your home and health — causing asthma, allergies, and even immune issues.
So, how do you get rid of it? Better yet, how do you stop it from coming back?
Take What Happened to Ben and Laura, for Example
They didn’t think too much about the musty smell in their hallway after it rained. There was a small dark patch on the ceiling, sure, but they figured it was nothing serious. A bit of spray and elbow grease seemed to solve the problem.
Then Laura’s asthma flared up. And Ben, who’s normally full of energy, started waking up tired. The kids seemed to be getting sick every other week, too.
It wasn’t until a big storm rolled through that Ben decided to check the subfloor.
When he opened the hatch, damp, stale air rushed out, like it had been imprisoned there for years. Then he checked the back of the door and found it covered in a carpet of black mould.
The first step was getting the mould treated to make it safe. Then, a specialist inspected the space and found the real issue: poor cross-ventilation combined with a small leak that had been working insidiously behind the scenes for years.
They installed bigger fans under the subfloor to keep the air moving, fixed the leak, and made sure everything stayed dry.
After that, things started to improve.
The Point? You Can’t Just Wipe Away Visible Mould and Call It a Day
Here’s how the professionals do it:
Strategy #1: Cleaning mould with chemical treatments. Professionals use industrial-grade chemical treatments to kill the spores and stop them from coming back. These solutions don’t just get rid of what you can see — they deal with the root of the problem. For example, a fungicidal spray can be used on walls or ceilings to prevent regrowth and keep the air clean.
Strategy #2: Removing mouldy materials. If the mould has got into something like timber, cleaning isn’t going to cut it. In those cases, the mouldy material needs to be removed completely and replaced. For example, if the timber’s covered in black mould and the spores have spread deep inside, it’s safer to rip it out and start fresh.
Strategy #3: Control moisture at the source. Mould loves damp spots, so fixing where the moisture’s coming from is non-negotiable. Roof leaks, burst pipes, or even a slow drip behind a wall — if it’s letting water in, it needs to be sorted straight away. For example, sealing up a leaky roof or fixing a dripping pipe isn’t just about stopping the water; it’s about cutting off the mould’s lifeline so it can’t come back.
Strategy #4: Improve airflow with proper ventilation. Mould thrives where air doesn’t move — places like attics, bathrooms, or even the back of a built-in wardrobe. Proper ventilation changes all that. For example, installing a quality exhaust fan in your bathroom prevents steam from hanging around, keeping surfaces dry and stopping mould from taking hold in the grout or corners.
So far, we’ve only really talked about removing the problem or making relatively minor fixes. But what about your home itself?
How Can You Make Your Home “Mould-Proof” During Your Next Reno?
Strategy #1: Use mould-resistant materials. Products like plasterboard, insulation, and paints made for damp areas are specifically designed to repel moisture and stop mould from taking hold. Whenever these materials are an option, it’s a no-brainer.
Strategy #2: Incorporate moisture barriers. If your renovation involves walls, subfloors, or basements, adding moisture barriers is an absolute must. For instance, a vapour barrier in the subfloor keeps the timber dry, even in the middle of a soggy winter.
Strategy #3: Improve natural drainage. Your renovation should include proper drainage to move water away from your foundations. This could mean installing French drains, grading the soil to slope away from the house, or extending your downpipes.
Strategy #4: Maximise natural light. Mould loves the dark, so designing your home to let in more sunlight is a natural way to keep it at bay. For instance, you could add skylights to the living areas of your home or enlarge your bedroom windows.
Strategy #5: Upgrade to double-glazed windows. Condensation is a mould magnet. Upgrading from single to double-glazed windows helps by insulating against temperature differences, which stops condensation from forming in the first place.
The Bottom Line? Prevention is Key
If you are going to renovate, you might as well go that step further to make it so mould would hate to live with you. It’s the best way to make sure you’re not constantly battling asthma, allergies, or random colds — or stressing about moisture destroying your home from the inside out.
With that said, making your home mould-resistant is just one small part of the renovation process.
That’s why we’ve put together a comprehensive guide for you to download:
5 Mistakes People Make When Planning a Major Home Renovation
It’s completely free and filled with tips to help you make the best decisions for your family’s health and comfort at home.
