Causes of Condensation


An average family of four contributes approximately 100 pints of water vapour a week. Daily tasks like using showers, tumble driers, kettles, bathing, cooking, drying clothes and breathing all contribute to this, meaning it’s hard to avoid.

Condensation is produced when warm air hits a cold surface, or when there is too much heat in your home. When moisture-packed warm air meets a chilly surface, it cools down quickly and releases the water, which turns into liquid droplets on the cold surface. The more moisture in the air the more likely it is that you will get condensation.

Good ventilation is the only way of preventing condensation.

Windows, doors and lofts used to allow the moisture and warmth to escape, but properties are now fitted with energy saving products such as double glazing, wall and loft insulation, which stop the moisture from escaping.

You should also look out for:

  • Washing machines produce two litres of water into the air for one load.
  • Kitchens and Bathrooms produce steam and moisture. Ensure you use extractor fans, when cooking use pan lids, use a bathmat and keep doors closed.
  • A flued gas heater which has a flue or chimney to carry the combustion pollutants and water vapour to the air outside the home.
  • A gas heater that has no flue and releases the combustion pollutants and water vapour directly into the room. Burning gas always produces water vapour. If there is not enough fresh air circulating in the room, water vapour can cause high humidity and wet surfaces.

Reducing condensation

There are a few things you can do in the home to reduce condensation.

  • Avoid indoor clothes drying, including over radiators.
  • Ensure condenser tumble driers regularly emptied or well vented.
  • Keep the temperature inside constant.
  • Move furniture away from walls.
  • Turn on, use and maintain extractor fans to ensure they offer adequate airflow.

Opening a window to remove condensation within the home will not reduce condensation. The weather outdoors tends to have more moisture and a higher humidity than indoors, therefore, causing condensation to form once you close the window.

Property can be affected if humidity levels are 50% or higher. Regular condensation on windows will lead to damage on both internal and external walls.

Will a dehumidifier help with condensation?

If your home is breathable, a dehumidifier could be a sensible solution. They are generally only effective in the room that they are placed and need to be emptied daily.

The effects of condensation.

The effects of condensation in a property are numerous; condensation can affect the occupant’s health, the energy efficiency of the property, the visual deterioration and the structural damage of the property. Damp and mould patches destroy carpets, flooring, wallpaper and furnishings. Similarly, externally, moisture becoming entrapped within the structure can result in long term corrosion of external walls, metal structures, timber rot, loosening of nails as timber swells, and cladding rot or swelling which can result in costly rectification work.

For advice on any structural damage caused by condensation, contact Chris at Mace Davies.