What is condensation?

Condensation occurs when there is an excessive build up of moisture in the air and especially during the colder weather.  There is always moisture in the air even if you cannot see it, but people create additional moisture in the homes by:

  • Cooking, or boiling water
  • Taking baths or showers
  • Drying clothes indoors

Warm moist air condenses and forms water when it cools; for example when it touches a cool surface. In your home these are outside walls, windows, wall tiles and even clothes. Condensation may be caused by the way your home is occupied, by lack of heating and ventilation provision or frequently by a combination of these.

If condensation cannot dry out it will cause mould to form on walls, in cupboards, on window sills and will cause mildew to form on clothes. Where there is inadequate ventilation in your home, condensation and stale air may result.

To control condensation

First of all, you need to ensure that the amount of moisture in the air is not excessive.

Look at your lifestyle within the building:

  • Produce less moisture by covering pots and pans and turning down the heat when boiling, switching off boiling kettles, and drying clothes outside, or in a well ventilated room
  • After a bath or shower, try to ventilate the room to the outside, not to the rest of the house – just opening a window (and closing the door) will help.
  • Dry clothes out of doors or in a cool area of the premises – this latter suggestion may sound strange, it will take longer but less moisture will be held in the air at any one time.
  • While drying clothes indoors, ventilate the room.
  • When people come with wet coats, hang them outside the living area to dry. A good reason for a porch.
  • Try to increase the change of air in the premises – increase ventilation. Add forced ventilation/ extraction to areas which produces a lot of moisture (kitchen, bathroom). Extractor fans are available with an air-moisture switch so that they operate automatically while the moisture in the air is above a set amount. Consider using a dehumidifier – domestic types are available and can remove a surprising amount of water from air.
  • Ventilation to let the moisture out by opening a bathroom or kitchen window for a while to let the steam to escape, or using an extractor fan; and by opening windows for a while each day to change the air in the house
  • Keeping your home warm by at least keeping a low back ground heat
  • Wipe down where moisture settles
  • Where furniture such as cupboards is against the wall, try to keep a small distance between the back of the cupboard and the wall particularly if the wall is generally cold.

To kill and remove mould wipe down or spray walls, ceilings and window frame/sills with a fungicidal wash. Ensure that you follow instructions for its safe use. These fungicidal washes are available at local supermarkets or DIY stores.