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Avoiding condensation

Condensation is the most common form of unwanted dampness in buildings and occurs when warm moist air comes into contact with a cold surface.

In just one day, the average family makes about 15 pints of water vapour.

This vapour stays in the air in warm rooms but turns back into water when it touches cold surfaces such as a wall, window or ceiling.

The four main causes of condensation

  • lack of heat
  • lack of insulation
  • lack of ventilation
  • moisture production

Problems caused by condensation

The most common indication of a condensation problem is water running down windows and walls. If ignored this can lead to water collecting on the window sills, decay in window frames, stained curtains and black mould growing on walls and woodwork.

How to prevent condensation

If you find water on the inside of your windows, on cold walls and surfaces, in cold rooms or near windows it is likely to be condensation. You may also find black mould on the walls or blue/green mould on leather or wood. Mould is usually found in cold corners, cupboards or on external walls inside the property.

In most cases condensation can be prevented by opening a window and making sure that all rooms within the home are heated adequately.

Tips to help you reduce condensation in your home

Keep all your rooms warm by using your heating system effectively and efficiently as much as you can afford. Turning your thermostat down by 1°C could cut your heating bills by up to 10%. 

Keep your central heating thermostat set between 18° and 21°C it's better to have heating on a low setting for longer to maintain a minimum temperature rather than heating to high temperatures at short bursts.

Ensure there is adequate ventilation in your home by:

  • allowing fresh air into your home by opening windows a little
  • using extractor fans if they are fitted, this is especially important after using your bath or shower

Reduce the amount of moisture produced by:

  • drying clothes outside when possible
  • making sure tumble dryers are vented outside
  • opening your kitchen window when you cook and keep all your other doors closed to stop steam spreading through the house
  • do not use Calor gas fires or paraffin heaters as these can cause condensation

If you think you might benefit from energy advice, an energy survey or advice on effective management of condensation please do not hesitate to contact us.

Page last updated:
26 Nov 2020

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