How to avoid Mould growth post floods

Floods can be one of the most damaging and devastating things you can ever experience as a homeowner, as seen with the seriously high levels of rainfall QLD and NSW has dealt with over the past weeks. Not only because of damage to homes and personal items but because of the multitude of health issues that can follow for some after being exposed to a water damaged building.

Remember Mould growth begins with water damage. Time is strictly the essence in these situations. Mould growth can start to take place in as little as 48 hours (some species such as Penicilliumand and Aspergillus can even start to germinate within 16 hours). The quicker you dry the area, the less food their is for mould growth.

For non-major water damage to indoors here is some advice on drying and preventing mould growth

I can not stress the importance in the drying stage of having a high quality dehumidifier running on continuous to actively remove moisture from the room. The number of dehumidifiers needing to be used will depend upon how big the moisture affected area is and how much moisture is your dehumidifier is capable of removing and handling the moisture. The bigger the water damaged area the more time it will take to draw the moisture out of the room. For example, if the whole house was affected by a flood, there may need to be many dehumidifiers going at once for several days. Dehumidifiers are especially efficient at drying deep, embedded moisture such as within the thick of carpet or wooden floor boards.

Drying guide to prevent mould growth in non-major water damaged environments

hygrometer, indoor humidity, humidity
Hygrometer used to measure indoor humidity levels

Run the dehumidifier continuously in water damaged rooms throughout the house. Make sure to close all windows and doors and turn the dehumidifier on to the lowest humidity setting (30% is ideal). You’ll need to keep the dehumidifier running for a minimum of 24 hours to a week to dry everything correctly. If you have a ceiling fan or tower fan this can be useful to have on as well to help with air circulation.

Purchase a cheap hygrometer (Jaycar often has them under $20) and monitor the indoor air humidity. We are aiming to get between 45-55% indoor humidity levels.

Use towels and tea towels to soak up any visible moisture. For carpets it might help to fold a towel and step on it a few times this can effectively draw moisture up.

Remember to keep all doors and windows closed during this process. And to empty out your dehumidifier tank when full. Some dehumidifiers can be fitted with an automatic drainage hose to the outside or drain, which is your best option if no one is occupying the house during the drying stage. This drying guide is for minor water damage only, (not major flooding). For major flooding it may be best to consult with an IICRC Mould Remediator who can advise your next steps.

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