Damp, mould and condensation

How to reduce condensation and mould growth

Following these steps can help to reduce the amount of condensation and mould growth in your home.


Produce less moisture

Ordinary daily activities produce a lot of moisture, to reduce this:

  • Dry clothes outdoors if possible. Avoid drying clothes indoors or, if you have to, dry them on a clothes airer in the bathroom with the door closed and either an extractor fan on or with a window open.
  • Ventilate tumble driers to the outside (never into the home).
  • Cover pans when cooking and turn down to a simmer when they boil.
  • Do not use paraffin or liquid petroleum (bottled) gas heaters as they produce large amounts of water vapour.
  • Run cold water in to a bath before the hot.

Remove excess moisture

  • Wipe the windows and windowsills of your home every morning if water has formed.
  • Open windows and turn extractor fans on before running baths and using showers. Ideally extractor fans will be linked to a humidistat that will automatically operate when moisture in the air is high or to the light switch with an overrun when the light is switched off.
  • Open curtains to allow for better ventilation and for natural light and heat to enter.
  • Clear windowsills of clutter that will restrict opening the windows.
  • Leave space between the back of furniture and cold walls. Only place furniture against internal walls if possible.
  • Ventilate cupboards and wardrobes and avoid overfilling them as this prevents air circulating.
  • Do not completely block chimneys and flues, fit with an air vent to provide constant ventilation.

Heat your home adequately

In cold weather, the best way to keep rooms warm and avoid condensation is to keep low background heat on all day rather than short bursts of high heat when you are in the house.

Try not to turn off the radiators in unused rooms as this could cause dampness and mould growth that you will be unaware of.

Good heating controls on your radiators, room thermostats and a timer will help control the heating throughout your house and help you to better manage costs.

  • Insulate and draught-proof. This will help keep your home warm and save money on your heating bills. Insulate the loft up to a depth of 270 mm.
  • Consider secondary or double glazing.
  • Consider cavity wall insulation.
  • Draught-proof windows and external doors. When draught proofing do not block permanent ventilators.

There is support available for help with heating or insulating your home.


Dealing with mould

Mould can grow on walls, ceilings, furnishings and even on clothes and toys, which can be upsetting and expensive to fix.

To kill and remove the mould:

  • carefully remove mould with a damp cloth and throw away after. Do not brush mould as this releases spores into the air.
  • wipe down affected areas using a fungicidal wash or diluted bleach, following manufacturer's instructions.
  • after treatment, redecorate using a fungicidal paint or wall paper paste. Do not paint over using an ordinary paint.
  • dry clean or wash clothes affected by mould and shampoo carpets.

Warmth and ventilation

Getting the right balance between warmth and ventilation is important and can be very effective.

By opening windows or ventilating your home it may appear that you are losing some heat, but this allows warm moisture-laden air to escape and dry air to enter your home.

Many people who have double-glazing installed experience problems with condensation and mould growth that they never had with their old draughty window frames. This is because all the natural draughts around the poorly fitted windows have been sealed. However, by using trickle vents or opening windows slightly, then the necessary ventilation level can be achieved. 

Ventilation needs to be provided for an appropriate amount of time depending on how much water you produce in the home and on weather conditions.

On a warm, dry day a home should be ventilated to the maximum. On a cold wet day ventilation may not be of any help except in a bathroom or kitchen where most water is produced.

It should not be necessary to leave all windows open all day.


Dealing with condensation is not always easy. Only carrying out one or two of the above steps may not solve your problem.

You need to do as many as possible every day, so that they become part of your habits and lifestyle.

Other things like making sure windows are fitted correctly and the seals are in-tact can help to reduce cold spots and the appearance of condensation mould.