We’ve all been there.

Whether you own an older or period-style home or are attempting to find a quality HVAC solution for a new build, mould is probably on your mind.

Mould is a common (and understandably quite intimidating) problem in many homes, and can cause a variety of health problems, including:

  • Allergies
  • Skin sensitivities
  • Chronic fatigue
  • Joint pain and weakness
  • Asthma
  • Headaches
  • Cognitive dysfunction
  • Respiratory infections

Scary, right? It is. But fear not – your award-winning G Store HVAC team can help.

In this article, we’ll examine some of the main reasons mould grows in homes, such as:

  • A high degree of humidity
  • Water damage
  • Poor circulation of air
  • Lack of proper maintenance
  • Cluttered, disorganised environments

Of course, solutions do exist. We’ll discuss some great options as we progress.

But first, here are some key statistics about mould growth in the home:

  • Mould can grow on virtually any organic substance as long as moisture and oxygen are present
  • The most common indoor moulds are Cladosporium, Penicillium, Aspergillus, and Alternaria
  • The optimal temperature range for mould growth is between 77 and 86 degrees Fahrenheit (25 and 30 degrees Celsius)
  • High humidity levels, typically above 60%, can also contribute to mould growth
  • Mould can cause various health problems such as allergies, asthma, and infections

Let’s dig deeper into some of the reasons why mould can make your home its own.

Does humidity cause mould?

In short, yes. In fact, humidity is one of the main causes of mould in the home. Generally, mould thrives in environments with a relative humidity of 70% or higher. This can occur in areas of the home that are poorly ventilated, such as bathrooms, kitchens, and basements.

And guess what: research shows that up to 50% of homes have humidity levels that are too high, which – in turn – increases the risk of mould growing in your living environment.

What can you do to decrease humidity in your home?

The first step is to monitor it. Many of the high-quality HVAC systems we stock at G Store include advanced monitoring systems which makes keeping humidity levels in check a breeze (literally).

How does water ingress cause mould?

Another common cause of mould growth is water damage.

Water leaks, floods, and other sources of water infiltration can provide the perfect breeding ground for mould. If water damage isn’t addressed promptly and with the highest degree of attention to detail, it can lead to significant mould growth.

Remember: water always takes the path of least resistance. It can be tricky to find some leaks, and – as a result – mould can grow in the most unlikely (or inaccessible) of places.

According to key statistics, water damage is the leading cause of mould in homes, with around 98% of basements and low-level areas of the home experiencing some form of water damage in their lifetime.

Does poor circulation of air cause mould growth?


Homes that are tightly sealed, whether that’s to conserve energy, restrict air leakage, or due to the building’s design, can easily trap excess moisture and air pollutants inside. The result of these cumulative set of circumstances is essentially poor circulation of air.

A significant study by the Environmental Protection Agency (EPA) demonstrated that indoor air pollution can be up to five times more polluted than outdoor air, which can lead to a higher risk of mould growth.

What else causing mould to grow?

In addition to those reasons discussion above, the other causes of mould in the home include:

  • Lack of maintenance (ignoring the key signs of mould growth including appearance, unclean surfaces and smell)
  • Poor construction (building that facilitate water ingress)
  • Cluttered environments (mould tends to grow behind items that are close to walls, floors or objects where humidity is a problem)

What can I do about mould in my home?

In short, the best defense against mould incorporates:

  • Consultation with a trusted HVAC professional
  • Taking steps to increase air circulation within your home
  • Choosing an HVAC system that helps you monitor, assess and manage humidity levels
  • Ensuring you keep on top of water leaks and any resultant damage
  • If you already have a problem, speaking to and hiring a professional mould remediation expert

The main types of HVAC systems available include:

  • Split-system and multi split-system reverse cycle air conditioners
  • Hydronic systems (usually installed as a subfloor system)
  • Ducted systems (usually installed as a subfloor system)
  • Panel and free-standing electric heaters and fans

To understand which system is right for you, call our friendly team today on 1300 137 567. We can easily provide and comprehensive and obligation-free assessment

Wrapping up

Mould in homes can be caused by a variety of factors. At the end of the day, the best solution is prevention. Speak with our team early, and often, to understand the solutions that are best-fit for you.

Visit our Learning Centre today to learn more, or give us a call on 1300 137 567

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