Controlling condensation

There are a number of things that you can do to reduce and even get rid of condensation from your home. Some are to do with controlling the levels of moisture in the air, while others are about reducing the number of cold surfaces upon which condensation can form.

1. Make less moisture

  • Don’t dry washing inside your home – all the water from your clothes will go straight into the air and as the air cools you will get condensation on your windows and walls in winter.
  • Put lids on your saucepans when cooking and turn down the heat –saves money on your fuel bill, by not using a racing boil you will reduce condensation problems too, rather simmer things instead.
  • Don’t use paraffin or bottled gas heaters – they produce lots of moisture – burning one litre of paraffin/kilo of gas puts about one litre of water vapour into the air which may well reappear as condensation on your windows or other cold surfaces.
  • Vent your tumble dryer outside – if your dryer is not a condensing one make sure you put the vent hose out through the wall or out of a window to ensure the hot moisture filled air produced by the machine does not steam up your home. Opening a window is not enough. Hose kits are available from most electrical and DIY stores.  Better still hang washing on a washing line!
  • Don’t keep curtains closed all day –  open them and pull them clear of the window and wall.

2. Increase Ventilation

  • Open a window when cooking and after showering/bathing – Boiling pans, hot baths and showers produce lots of steam – opening a window ensures this steam can get out rather than condenses inside your home. It also helps to keep your kitchen and bathroom doors shut when these rooms are in use and for about 20 minutes afterwards to stop moist air getting into other rooms. When your kitchen, bathroom or other rooms are not in use, leave doors open so heat can spread evenly through your home.
  • Allow air to circulate where possible – Avoid putting furniture against outside walls of your home. Inside walls (between rooms) are always warmer and are not prone to condensation. Leave a gap between the wall and the furniture so air can circulate and ensure that wardrobes and cupboards are properly ventilated to prevent mould growing inside or behind them. You may in extreme circumstances need to hang pictures with a clear 12mm gap behind them everywhere.
  • Use the trickle ventilators or night vents that will be in some windows  when you are away from home and your heating is off and in the summer when you are out or away. You need ventilation help get rid of moisture which is produced in your home all the time, if you are having problems with condensation even after following the advice above then you may need to increase ventilation and/or use a little more heating, but bear in mind that it is easier to get rid of the source of the problem than the results of it.

3. Keep your home warm

In order to keep your house warm it should be insulated, draughts will cool the building and they have the opposite effect to the heating. Ventilation is however necessary in all buildings and it is best if this is controlled, opening windows, vents or fans as opposed to allowing draughts to it in an uncontrolled way.

Where the temperature of a wall falls below 12°C there is a danger of condensation, in a bathroom almost whatever the wall temperature is condensation will occur even in summer, it is important to open the window, close the door and run the fan if there is one. Further when the walls are wet or running with condensation they should be squeegeed and wiped. Continuously wet places will tend to grow moulds, wiping then opening windows and shutting the door is the best way to avoid this problem.

Background heating even at a low level, 15°C can help reduce problems, with some areas being made warmer as and when required, in the case of the elderly further advice should be taken concerning temperature regimes.

4. Remove wetness and mould as soon as you find it 

  • Wipe the water from your windows and sills with a cloth – but make sure you wring your cloth out in the sink. Lots of people put the wet cloth on a radiator to dry – the water then evaporates back into the air and re-appears as condensation when the temperature drops. Wipe the water off every time it appears to help get rid of the excess moisture in your home.
  • You MUST remove mould as soon as you find it to stop it spreading and causing more damage to your home. You can get special cleaning products from DIY stores or  you can try bleach mixed 1 part bleach to 4 parts water (always wear gloves and goggles etc but beware as bleach may take the colour out of the paint).

For further guidance, the United Kingdom Centre for Moisture in Buildings (UKCMB) has a video with a reasonable explanation and advice, alongside their report