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One of the most common complaints concerning housing, is that of condensation and/or mildew growth on walls, ceiling, in cupboards etc. Mildew growth occurs when the atmosphere within a dwelling remains damp and when little ventilation is provided.
Condensation and subsequent mildew growth can be caused by faults in the dwellings construction, such as lack of insulation, but more commonly is caused by moisture generated by activity within the dwelling, such as cooking, showering, failure to ventilate etc,.
Keeping Condensation and Mildew at Bay
Condensation and mildew in homes are mainly winter problems but they can occur year round in some situations. The Environmental Health Department of Central Hawke's Bay District Council is regularly asked for advice on controlling condensation and mildew in the home. The purpose of this pamphlet therefore is to provide some simple guidelines to minimise the moisture burden inside your home, therefore reducing the level of condensation and mildew.
Condensation occurs when the air becomes saturated with water vapour to the point where it cannot hold any further moisture, i.e. high moisture burden. In areas where there is a temperature difference between two surfaces, such as with windows, some of the moisture will condense on to the colder surface. Condensation can leave water stains and if persistent, can lead to mildew growth and will help rot set in.
Mildew and other fungal growths grow from spores that abound everywhere. Mildew needs moisture in order to grow so the more persistently damp a situation the more likely mildew will grow.
How can you reduce the level of Condensation? There are two ways to reduce the level of condensation in your home - by heating and ventilation. Heating will raise the air temperature and allow the air to hold more moisture, ventilation then removes the moisture to the outside.
If carrying out building repairs or alterations, you should also:
Mildew can usually be washed out of clothing and curtains; however, if this is not done in time, it can leave permanent stains.
For mildew growing on walls and ceilings, clean the area down with a damp cloth and household bleach. 1 part bleach to 4 parts water is recommended. Use a test-patch to make sure the bleach does not effect the paint or wallpaper colour. If the colour is damaged, try a fungicide solution, which you can purchase from most paint or hardware shops.
If re-wallpapering, strip the old paper off the wall first. Next paint the wall with a fungicide solution. When it is completely dry, re-hang the wallpaper using a paste containing a fungicide agent.
If re-painting, use a paint containing a fungicide agent but never paint directly over existing mildew.
When the mildew has been removed, ensure it does not recur by keeping your home warm throughout and moderately ventilated.
So remember to prevent condensation and mildew, it's a bit like real estate, the golden rule is
"ventilation, ventilation, ventilation"
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