Dampness

Press, 30 April 1981, Page 23

Dampness

Mildew and condensation are mainly winter problems. A survey a couple of years ago showed that nearly half of all New Zealand homes have mildew. Mildew can occur on shoes and clothes, in wardrobes and on wallpaper, curtains and ceilings. It is a primitive form ol plant growth originating from spores that abound everywhere,and it will grow in any home where humidity remains high. Condensation, too, is widespread but appears to be heavier in cold climates where it. occurs on windows, especially metal-framed ones, on walls and on ceiling linings. Ail air contains water vapour,. but can hold only a limited amount without becoming saturated. The higher thettemperalure, the more it catf’hold Eiit if there is toe much moisture for the temperature, some will condense on cold surfaces. Severe condensation in the house during winter, or a musty smell, may be signs ol

dampness underneath. It is a wise precaution to look underneath in any case, as better ventilation may be necessary, extra drainage or a polythene sheet on the ground. Or the trouble may be simly a plumbing leak or blocked vents. Humidity inside can be kept down by ventilation and heating. Ventilation to take away moisture released by such things as breathing and cooking is the most fundamental need in combatting high humidity. If there is not enough, nothing else can help, whereas too much prevents the house' from getting warm. Little and often is the key to effective ventilation. Many windows open slightly are better than one open fully. -. Short bursts of vigorous ventilation are ,- not much help except when flushing out moist air after a shower or. bath. Most people close doors when taking a shower or a bath, and this helps prevent, steam from spreading to other rooms. Try to get rid of steam from cooking and showers direct to outside. An extractor fan in the wall over each of the stove and bath Is particularly helpful, but some heating is also needed. To prevent mildew, make sure there is some ventilation in all rooms at all times and keep the house warm but not hot. . Try to keep the indoor temperature at least five degrees warmer than outside all the time through the winter. A little heating continuously does more good than a lot during the evening only Even so,, it is desirable to orovide permanent ventilation to wardrobes by leaving .he doors ajar or providing ioor vents, top and bottom. Both insulation and heatng througnout the house will lelp to lessen the chances of mildew and condensation but lot prevent them. Keeping down moisture input is also lecessary. along with insula.lon where possible Try to avoid pots and pans loiling longer or harder than leeded. or without lids on. Try to avoid bathroom iteam spreading through the louse 1 and open windows' wider if indoor clothes frying is unavoidable. Clothes driers must be iucted to the outside. Windows are a good guide - if they start steaming up, ipen them a little wider.