Wiping out winter condensation

Press, 27 April 1989, Page 34

Wiping out winter condensation

Condensation and winter go together in many homes. Condensation forms when the warm air inside a home meets the cold surface of walls, ceilings, doors, mirrors and windows if a home is not adequately ventilated. All air contains water vapour. The warmer the air, the more water it can

hold. In a home, vapour is released by cooking, washing, drying clothes and breathing. Condensation and mildew occur in almost half the homes in New Zealand, according to the Building Research Association of New Zealand. One home in five has repeated or prolonged

attacks, and in one home in seven, condensation leads to damp wall linings. Condensation can leave unsightly water stains, and if it continues, will foster mildew growth. Eventually rot will set in. Mildew occurs in mild and severe climates, disfiguring wallpaper, curtains, clothes and ceiling linings. It is a primitive form of fungal growth which grows from spores in the environment. It cannot grow if there is no moisture. There are two ways to eliminate condensation and mildew: by heating and ventilation. Heating will raise the temperature and allow the air to hold more moisture. Ventilation takes moisture outside. Constant ventilation is a basic requirement but too much ventilation will prevent the house from getting warm. A balance is important:

having many windows open a little all the time.' If they continue to steam up, open them wider. Short bursts of vigorous ventilation get rid of large quantities of moist air released from cooking or bathing. Simple precautions get rid of condensation: • Vent a clothes dryer outside. • Keep the house warm, about five degrees higher than outside. • Prevent large amounts of steam spreading through the house.

Use extractor fans in the kitchen and bathroom. Close the doors to these rooms when bathing or cooking. • Use windows as a guide. If moisture starts collecting, open them wider. • Wipe moisture off glass. Take the wet cloth away to out. • Provide permanent ventilation to wardrobes by louvre doors, or leaving doors ajar. • Insulate ceilings of existing homes. Warning signs of under-

floor dampness in homes with suspended floors are: a musty smell in the house, severe condensation and mould growth, dark coloured staining in clear-finished particle board floors, bubbling of sheet vinyl, water stains on ceilings, and noticeable sagging of the flooring. The dampness could come from leaks in water pipes, leaks from waste pipes or their connections to baths or shower trays, blocked drains, poor downpipe connection or rain penetration through wall cladding.