Heavy rainfall, cold temperatures and heaters all cause condensation that lead to indoor mould problems in houses.
Heike Neumeister-Kemp is happy to be called the Mould Lady. As a mycologist, she is fascinated by understanding how and where mould grows and how to get rid of it.
“You will always find mould in the grout of your shower and around your bathroom, which is not really a concern, although of course you should clean it off,” Dr Neumeister-Kemp said.
“If it gets bigger than your hand or you have blotches everywhere, then you have a real problem.”
Most mould, she said, comes from excess water and the types of fungi that grow give off micro toxins which can make people ill.
Bleach not effective against mould
The biggest misconception is that bleach destroys mould.
“The fungi contain melanin, and the bleach just takes the colour out, but the fungi are still there, you are just masking it,” she said.
“Six weeks later it appears to come back, but it was never gone.
“The best thing to do, if you have a vacuum cleaner with a hepa filter, is to first vacuum all the loose spores off, then take a microfibre cloth and use vinegar solution, and gently wipe off the mould.
“The vinegar attacks the fungi mechanically, so it actually, via osmosis, penetrates into the structure and explodes it, so you actually kill the fungi.”
The vinegar solution should be made from white wine vinegar, with 80 parts vinegar and 20 parts water.
“Methylated spirits will also kill mould in a 70-30 ratio. We use it with timber, and other highly porous material, methylated spirits is really good.”
Gas heaters cause condensation in winter
One of the biggest causes of condensation and mould in Australia is the widespread use of free-standing, unflued gas heaters in winter.
“An unflued gas heater produces lots of C02, together with all the water vapour in the air, condenses on the wall, and then the C02 feeds the mould.
“Hot air holds a lot of moisture, and at night when the air cools down, the moisture condenses on the walls. The water is then available for mould.
“The mould also gets fat on the gases as well. It’s really unhealthy to use an unflued gas heater; it’s like parking your car in your lounge room.”