The menace of mould and how to manage it

Mould is a common problem, especially in older houses and units

By Jade Tweedie

05-11-2018 |
Condensation and mould can occur in any type of home construction, including weatherboard, brick veneer, solid brick, masonry veneer and monocrete.

Mould is a common problem, especially in older houses and units where ventilation may be inadequate.


Mould is a form of fungus and is spread primarily by airborne spores that will develop and grow on almost any surface providing the following conditions are present:

•A relevant indoor humidity of 80% or higher
•Moisture, usually from condensation. Mould can develop in the absence of condensation, but its growth is accelerated by the presence of moisture
•A nutrient. Research shows that certain ingredients in most paints, household dust, and cooking fumes all provide excellent food for mould

Sooty mould, the most common type, leaves surfaces with a brown or black stain and usually occurs on the walls and ceilings of bathrooms, bedrooms and in cupboards. Untreated, this mould will spread to other rooms in the house.

Green furry mould grows on organic or organic-bearing surfaces, such as shoes or clothes.

The circulation of dry air retards mould growth. It follows that proper ventilation will prevent most mould growth.

How to prevent condensation and mould !

Avoiding mould is all about avoiding condensation.

Some ways of doing that include:

•After a bath or shower, the room should be ventilated to the outside, not to the rest of the house – just opening a window (and closing the door) will help. If present, leave an extractor fan running for at least 10 minutes.
•Dry clothes out of doors or in a cool area of the premises – this latter suggestion may sound strange, it will take longer but less moisture will be held in the air at any one time.
•While drying clothes indoors, ventilate the room.
•When people come in with wet coats, they should be hung outside to dry (such as on the porch)
•Keep exhaust fans clear of fluff and dust
•In winter, you still need to open windows on a daily basis (wait till the warmest time of day)
•Avoid the use of unflued gas or kerosene heaters
•Wipe surfaces as soon as you see any condensation appear
•Allow sunlight in whenever possible by opening blinds during the day
•Remove any sign of mould growth on walls, ceilings and furniture using diluted household bleach
•Furniture should not be pushed up against walls. This creates dark airless areas and allows mould spores to grow