How Mould Can Easily Form After Wet Weather—and What You Can Do About It

If you’ve recently experienced days of steady rainfall (like we have from ex-cyclone Aflred here on the Gold Coast) or prolonged damp conditions, you might be facing an unexpected guest in your home—mould. That musty smell, the dark spots creeping along walls, ceilings, and furniture? That’s mould setting up shop, and once it takes hold, it can be tough to evict.

Mould thrives in damp, humid environments, which makes wet weather the perfect breeding ground. But with some quick action, you can stop it in its tracks and keep your home (and your health) safe.

Tip: We personally love and always have our Mould Aroma Gel room sanitiser in rooms that are prone to dampness (bathroom, laundry), get them here.

Why Does Mould Form After Wet Weather?

Mould spores are naturally present in the air, but they need moisture to grow. After periods of wet weather, excess moisture can linger in your home due to:

• Flooding or water leaks – Water can seep into walls, floors, and furniture, creating hidden pockets of dampness.
• High humidity – The air after prolonged rain is often thick with moisture, making it hard for surfaces to dry.
• Poor ventilation – If windows and doors are closed to keep out the rain, airflow is reduced, trapping moisture inside.
• Damp building materials – Waterlogged drywall, insulation, and carpets can take a long time to dry, giving mould the perfect environment to grow.

How to Prevent Mould After Wet Weather

The good news? You can take steps to prevent mould from taking over your home. Here’s how:

1. Act Fast: Dry Out Your Home

Mould can start growing within 24 to 48 hours, so time is of the essence. If it’s safe to do so, open windows and doors to improve air circulation. Use fans and dehumidifiers to speed up the drying process. If water has soaked into carpets or furniture, consider professional drying services.

2. Check for Leaks and Seal Them

Inspect your home for leaks in the roof, walls, or plumbing. Even small drips can create long-term moisture problems. Repair any leaks as soon as possible and consider waterproof sealants for vulnerable areas.

3. Clean and Disinfect Damp Surfaces

Wipe down wet surfaces with a solution of water and white vinegar, hydrogen peroxide, or a mild bleach solution to kill any existing mould spores. Avoid just using water, as this won’t prevent mould from returning.

4. Improve Ventilation

Good airflow is crucial in keeping mould at bay. Use exhaust fans in bathrooms, kitchens, and laundry rooms. If possible, keep windows open during dry periods to let fresh air circulate.

5. Remove and Replace Water-Damaged Materials

Unfortunately, some materials, like soaked drywall, insulation, and carpets, may be too damaged to salvage. If they remain damp for too long, mould will continue to spread. Remove and replace them to avoid long-term issues.

6. Monitor Humidity Levels

Using a hygrometer, keep your indoor humidity below 60%. Dehumidifiers and air conditioners can help maintain the right balance, especially in tropical climates.

What If Mould Has Already Started to Grow?

If you notice mould forming, don’t ignore it—it won’t go away on its own. Mould exposure can cause health issues, especially for those with allergies, asthma, or weakened immune systems. Small patches can be scrubbed away with mould-killing solutions, but if it’s widespread or keeps returning, you may need professional remediation as its not worth the risk to you or your families health.

Stay Proactive

Prevention is always easier than cleanup. After wet weather, stay vigilant—dry out your home, check for leaks, and keep an eye on humidity levels.