Summary
Read the full fact sheet- Mould is a type of fungus that lives on plant and animal matter.
- Mould grows best in damp and poorly ventilated areas.
- Airborne mould spores are commonly found in both indoor and outdoor environments.
- For more information and advice on mould issues, contact the Environmental Health section of your local council.
- Seek expert advice from your insurance company before cleaning or disposing of water or mould-damaged items after a flood.
- If you've decided to remove mould, make sure there is good ventilation and wear protective clothing.
On this page
About mould
Mould is a type of fungus that lives on plant and animal matter. This can include:
- building materials like wood and gypsum plasterboard
- furnishings like carpet and curtains
- paper, cardboard, books and boxes.
Mould grows best in damp and poorly ventilated areas and reproduces by making spores.
Airborne mould spores are commonly found in both indoor and outdoor environments. When they land on damp spots indoors, they may begin to grow and spread. There is no practical way to eliminate all mould indoors; the way to control indoor mould growth is to control the source of moisture.
It is important that your home has good ventilation to minimise internal moisture and prevent mould growth.
What mould looks like
Mould is not always easy to recognise. It often looks like ‘fuzz’ or appears to be a stain, smudge or discoloration. The most common moulds are black, green or white. However, mould can be many other colours, ranging from grey to orange to brown and can also change depending on age or life-stage.
How mould affects health
Mould in buildings can trigger nasal congestion, sneezing, cough, wheeze and respiratory infections. Mould can also worsen asthma and allergic conditions.
People who are more susceptible to these symptoms and other serious health effects include those with:
You should seek medical advice if you are concerned about the effects of mould.
Causes of mould growth indoors
Mould only grows when there is sufficient moisture on a surface or humidity in the air. Common causes include:
- leaking roofs and walls
- faulty plumbing, including blocked gutters and downpipes
- condensation from cooking, showering and clothes drying
- areas with poor air circulation (cupboards, corners, furniture against uninsulated outside walls).
Actions you can take to reduce mould
The most important actions you can take to prevent mould in your home are those that minimise moisture. The cheapest and easiest way of reducing moisture and humidity levels is opening a door or window to ventilate a room. Use exhaust fans where available.
- Fix leaky plumbing, roofs and other building faults.
- Ensure gutters are cleared and maintained.
- Reduce condensation in the home by:
- using exhaust fans or opening windows in the bathroom and kitchen when showering, cooking or using the dishwasher
- wiping up excess water caused by condensation such as on windows and shower glazing
- airing the home regularly by opening windows and doors on warmer days
- venting clothes dryers to the outside and cleaning lint filters in line with the manufacturer’s instructions.
- Use reverse cycle air conditioning and or mechanical dehumidification if available.
- Ensure adequate exhaust openings to the outside of the building if using evaporative cooling. Evaporative coolers increase the moisture content in indoor air, so the manufacturer’s instructions should be followed to ensure airflow in the home.
- Maintain and service heating, ventilation and cooling systems following the manufacturer’s instructions.
- Use a vacuum cleaner with a HEPA (high efficiency particulate air) filter.
- Avoid placing mattresses on the floor or surfaces without adequate ventilation.
- Vacuum, and or turn mattresses if it can be done safely.
- Increase air circulation around furniture by moving the furniture away from the walls.
Rental properties with mould issues
When a rental property has mould, the owner should fix any mould caused by faults in gutters or other fixtures. The tenant should ensure that extractor fans are used when available and the home is aired regularly where possible.
Sometimes, the cause of the mould growth may be due to a building fault that may not be easily rectified.
If as a tenant, you have taken measures to make sure the building is properly ventilated and mould is still growing, you should raise the issue with the owner.
Information on mould in rental properties is available on the Consumer Affairs Victoria’s website.
Tenants seeking further advice on their rights can also contact the Tenants Union of Victoria on (03) 9416 2577.
Testing for mould in your home
Where mould is visible, it is generally not considered necessary to test for it in the home. However, not all mould is visible, as contamination may be in cavities or the ceiling. If you can see or smell mould, you need to clean up and remove the mould immediately, as mould can damage surfaces it grows on.
If you suspect mould contamination but cannot find the source of the problem, or if you have already taken measures to prevent mould from growing and you are still having problems, you could hire an occupational hygienist or environmental health and safety professional. For a fee, these professionals can provide specialist mould testing and consultancy services.
Where to get help
- In an emergency, always call triple zero (000)
- Your local GP (doctor)
- Nurse-on-Call Tel. 1300 60 60 24 for health information and advice (24 hours, 7 days)
- Environmental health section of your local council
- Your insurance company
- Consumer Affairs Victoria Tel. 1300 55 81 81 or for National Translation Services, Tel. 131 450 and ask to be put through to Consumer Affairs Victoria
- Tenants Union of Victoria Tel. (03) 9416 2577
- Building and Plumbing Commission – Dispute resolution services
Flood information in community languages
- Floods: mould and your health, Health Translations
- Floods: animals and insect hazards, Health Translations
- Returning home after a flood, Health Translations
- Emergency, crisis and support services in Victoria, Health Translations
- FloodSafe (audio), Health Translations
- Floods, Department of Health, State Government of Victoria
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