As many as 60% of Australian homes could potentially have mould within their homes.

Mould is ugly and can potentially damage your home and belongings.

And that mould could be growing in hidden corners or walls of your property without you even being aware of it. The problem is often exacerbated in winter because of the use of heaters combined with poor ventilation.

After all what’s the point of opening your windows when you’re trying to heat your home? Yet that heating is often contributing to the moisture levels in your property.

How to find mould in the house - checklist

The thing is mould loves moisture. And most Australian properties will have potential moisture issues including leaking plumbing and condensation build up. If unnoticed or left untreated a mould contamination can quickly spread inside walls and through insulation as well as through your belongings.

Ultimately, you could be facing expensive repair bills so it’s important to know the warning signs of the presence of mould.

The earlier you remove mould and identify and repair the associated moisture problems the better.

House Smells Musty After Rain or a Holiday?

You’ve returned from a lovely holiday and you open the door of your home… whew, what’s that stale, musty, pungent smell?

It’s quite likely that it’s mould. That mould smell is the result of microbial volatile organic compounds (MVOC) that are produced through the fungi’s metabolic processes.


The warmer atmosphere inside your home on a winter’s day will still cause condensation to form on the windows when the temperature outside drops.

This moisture can then drip down and seep behind window frames, carpets, walls, and into your curtains.

Older houses especially can be prone to moisture problems thanks to structural defects such as poorly designed or clogged window flashings.

Heavy rain and external moisture can also cause moisture problems inside your property too, while you’re away.

Yes, you might be able to mask that smell by opening all the windows and doors for ventilation. But even if you temporarily get rid of the odour you aren’t eliminating the source of the problem.

And guess what? That mould is continuing to grow and will continue its silent steady invasion until you take serious action.

mould vs mildew images

Musty vs Mould - When Should I Worry About the Smell?

There are dozens of mould varieties that could be present in your home.

But both musty and mouldy smells indicate a similar problem: moisture loving mould is lurking somewhere in your home.


In general terms musty odours are probably not as over-powering as mouldy smells and possibly indicate that the problem is still in a relatively early or localised stage.

Mould loves damp dark corners such as behind furniture or with wardrobes and this means you’ll often smell the mould before you see it.

And if you can see obvious signs of mould the situation might be a little bit like the iceberg effect: there’s a lot more hidden that you haven’t found. 

Locating the Source of the Smell

The “mould smell” effect can have different locations and it doesn’t always mean you have a mould problem.

Next, you’ll want to try and narrow the smell down a little more precisely.

Check the usual culprits:

  • Behind curtains and blinds – at the top and the bottom too.
  • Furniture backing on to walls, especially tall boys, bottoms of draws and display cabinets.
  • Cupboards and wardrobes, especially if they’re not used much.
  • Laundries, bathrooms, and other areas that routinely experience high humidity or dampness – bathroom ceilings are most common with mould forming close to external walls and windows.
  • Check underneath basins and inside kitchen units or anywhere that has water carrying pipes.
  • Check around the hot water cylinder for any possible leaks.
  • Cracks in brickwork or rendering that might allow water entry to your property.
  • Drains – blocked drains might be causing a build-up of water underneath your house and creating dampness issues through the floor.
  • Check window and door flashings and clear out any clogged drainage holes and channels.
  • Check under your home – ground water build-up in the sub-floor and travel up walls leading to rising damp.

If you have found evidence of visible mould it is time to call in the professionals.

Download Your Free Checklist For Where to Look for Mould - Click on the image below!

mould property checklist

Finding the Source of Mould

It’s critical to identify these sorts of problems as soon as possible because by the time you notice the smell or the presence of mould on the wall or ceiling significant damage will have occurred.

Some insurance companies may not even cover you if your property sustains damage as the result of gradual damage caused by a long-term leak. And mould may be causing damage even though you are not able to smell it. 

It’s worthwhile running a check around your property at least once or twice a year to check for any signs of mould contamination.

In addition to the above internal checks take a walk around the outside of the property.

Check things like:

  • Cracks in brickwork or rendering that might allow water entry to your property.
  • Drains – blocked drains might be causing a build-up of water underneath your house and creating dampness issues through the floor.
  • Check window and door flashings and clear out any clogged drainage holes and channels.

Other common sources of mould include leaking plumbing, leaking roofs or other external leaks.

Don’t forget to clean out guttering and while you’re there check out the state of your roof too. If you see any repair work that needs to be done don’t put it off. Deferred maintenance is one of the leading causes of serious leaks and mould problems.

However, the only way to really find and eliminate mould effectively is with a professional mould removal and remediation service.

Your friendly Mould Cleaning Australia team offer free inspection reports based on accurate air quality measurements, infrared imagery, and humidity and temperature readings.

We’ll get to the real source of your mould issue faster and more accurately that simple visual checks or the nose test can ever achieve.

woman smelling the air

AC Units and Mould

AC units and ventilation shafts also provide ideal environments for mould growth. Those dark spaces and the presence of moisture and dirt combine to make a very homely environment for mould to thrive in.

It’s definitely worth getting your AC units regularly serviced and cleaned to make sure that mould is not getting a foothold in your home.

High Humidity - Do Dehumidifiers Help?

Yes, dehumidifiers can help as they reduce moisture levels however it is ideal to locate the water source and stop it entering within the home.

Mould Cleaning Australia will assist in identifying the contributing sources and giving your recommendations for long term solutions.

How to Eliminate Mould and Musty Smells

Identifying the source of the mould is only part of the battle.

You need to fix the source of the moisture, remove the mould and eliminate all the mould spores including the spores hiding in roof cavities and other difficult to access sub floors.

The only really effective way to do this is through the services of a professional mould removal agency. Mould Cleaning Australia are the go-to mould remediation and removal experts.


With the aid of infrared imagery, humidity, air quality, and dew point temperature readings we can quickly identify any underlying structural issues too.

Our safe mould elimination processes use industry – leading products. The two-stage process will eliminate all mould from surfaces as well as eliminating mould spores from the air in your property and from cavities such as ceilings.