Controlling mould after a flood
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Control and eliminate mould after a flood to reduce health risks for you and your family.
Mould is a type of fungi which belongs to a group of organisms including mushrooms and yeasts.
To allow mould spores to grow and reproduce, a food source (dust, dirt or organic matter) and moisture is required.
Mould can be black, grey, green or white. Mould often looks like a stain or smudge, and may smell musty.
Moulds are present virtually everywhere, indoors and outdoors and can grow in and on materials such as:
Mould can also grow in decaying leaves, stale damp soil and compost.
Parts of the house that are prone to mould growth are those areas with:
When water is heated it changes into vapour. Condensation occurs when vapour cools and changes back into liquid.
When the air is already moist, condensation occurs with the slightest drop in temperature.
Avoid conditions encouraging mould growth by using heat, insulation and ventilation.
Moisture and humidity levels are required to support mould growth.
The cheapest and easiest way of reducing moisture and humidity levels is by ventilating a room by opening a window or door. All areas of the house should be continuously ventilated where possible.
The most effective method of reducing moisture is to use exhaust fans in areas where water vapour is created. There must be enough ventilation for an adequate intake of fresh air to replace the moist air.
Condensation and mould growth can be reduced by providing a continuous low level of dry heat. Continuous, even heating will allow warmth to penetrate the walls and ceilings. On cool days try to keep the inside temperature at least 5°C higher than the outside temperature.
Condensation and mould growth will be minimised if your house has good
insulation. Insulated walls and ceilings stay warmer, reducing condensation, and also keep drying heat in.
The most common types of moulds are not hazardous to humans,
however some moulds which may be found inside your home may cause
health problems. This will depend on:
Some moulds may:
Keep windows and walls dry inside the home by:
Keep the roof, cladding and guttering in good repair.
Ensure that stormwater is discharged to an appropriate outlet.
Reduce air moisture from kerosene heaters or unflued gas heaters by:
Reduce moisture/humidity levels by:
Reduce air moisture by:
Mould should be removed as soon as it appears. Completely eliminating mould and its causes can take some persistence.
Small areas of mould can be cleaned by using a bleach mixture (1 part bleach to 3 parts water) or a suitable commercial product (follow the manufacturer’s instructions).
Wear rubber gloves, take care not to splash the cleaning solution and make sure the area is well ventilated.
Don’t dry-brush the mouldy area as a brush can flick mould spores into the air which may cause health problems.
If mould returns, there may be an underlying problem. If mould contamination is extensive then a professional cleaner should be consulted.
If a mould-affected room is to be painted:
For further information on mould contact either: