Condensation accounts for approximately 70% of all domestic damp problems and can result in unsightly mould. the following advice will help you avoid such problems and live in a condensation-free home.

What is condensation?

Air can hold more water vapour when it is warm than when it is cold. When warm air is cooled, such as when your home heating system is switched off at night, it will deposit the water it can no longer retain as condensation on a cold surface. A similar effect can be demonstrated by breathing onto a mirror or other cool surfaces.

What causes it?

An average family of four to five people can produce upto 17 litres of water vapour a day. This can be from drying wet clothes on radiators or using the tumble dryer, having hot baths or showers, boiling kettles, cooking and of course breathing. That's a lot of water vapour being stored by the warm air in a typical, centrally heated, double glazed home.

Once the temperature in the home drops, such as at night time, all that water vapour that has built up during the day will then be deposited on any cold surfaces such as windows and walls.

How can it be prevented?

If you have misted or streaming windows, and in extreme cases, walls that are wet to the touch and black mould growth, you are most certainly suffering from condensation. However, do not panic, there are some easy steps to rectify the situation.

  • Dry washing outside where possible
  • Cover saucepans when cooking
  • Vent your tumble dryer outside
  • Increase ventilation in the kitchen and bathroom particularly whilst showering or cooking
  • Shut the bathroom/kitchen doors when cooking or bathing
  • Opening the window vents often found in UPVC windows

New research suggests drying laundry in the home poses a health risk to those prone to asthma, hay fever and other allergies. A study carried out by Mackintosh School of Architecture found that many homes had too much moisture indoors. Up to a third of this moisture was attributed to drying laundry.

You can also find out more information in our Condensation leaflet.