Many houses in New Zealand have unwittingly greeted mould into their homes in one way or another. This uninvited guest can be extremely hazardous to health - causing symptoms similar to hay-fever. But what exactly causes mould? While we know that mould loves moisture, there are a few other leading causes of mould, which are often overlooked. 


Many New Zealand homes are prone to mould because of the construction techniques throughout the decades. Villa style properties tend to lack insulation and are ‘a bit chilly’. Then you step into houses built in the 60s and 70s and those built after the 90s, which are prone to ‘leaky home’ syndrome. With poor construction and insulation, there is often mould lurking. 


Poor Ventilation

If your home has poor ventilation, there could be areas in the home where the moist air stays stagnant. If this air sticks to the surfaces instead of ventilating throughout the home, you will get patches of moist surfaces which will lead to mould.

TIP - Make sure you have your windows and/or doors in the house open to let the air flow through properly.


Leaking pipe

The black mould of nightmares is often caused by a leaking pipe. Because the pipe is hidden in the home’s framework, this kind of mould goes undetected. It’s not until you strip back the wallpaper or jib board that you will see the damage caused.



This is when mould is on high alert. The damp areas will develop into mould within 24 hours - and this will be rife through your property. If you have flooding within your property make sure you get a flood restoration team straight away to avoid damage. 



Mould likes humidity - because it loves moisture. When humidity is above 55%, this is when it tends to grow. If you dry your clothes indoors, you may notice that the ceiling above the clothing could be damp, and this is where you will first see signs of mould growth.

TIP - use a dehumidifier in the home and make sure to keep a fan going to keep air flowing. 


Cold surfaces like concrete floors or metal pipes are perfect surfaces for condensation. In those chilly, crisp mornings you may notice condensation droplets. This condensation and collect and settle leaving the area damp.

TIP - if you notice any damp areas, be sure to wipe the surface down and dry it as much as possible.

Lack of sunlight

If you’ve ever ventured to a basement, you’ll notice how it can often smell, well, damp. A lack of sunlight is also one of the causes for mould. While it’s not the leading factor, sunlight slows down mould spores growing.

Having mould in your house can really be a nuisance, but it can be prevented. If you need more advice or help on mould prevention or removal, be sure to contact the team at Chemcare on 0800 800 646.