Condensation, damp and mould


Everyday activities such as cooking, drying clothes, boiling kettles and taking showers and baths, produce warm air containing a large amount of water vapour.

If the moist  warm air cannot escape through an open window or air vent, it moves around until it finds a cold surface where it cools and forms condensation, which can lead to damp and black mould.

Condensation is most likely to appear on windows, colder parts of walls, around external door and window openings, and where ceilings and floors meet with outer walls. It can also appear in areas where air circulation is restricted, such as inside cupboards and behind furniture that is placed against an outside wall.

Here are some simple steps to reduce condensation:

  • When condensation appears, wipe it away.
  • Put lids on saucepans while you are cooking to reduce steam.
  • Avoid drying laundry on a clothes airer or radiator. If you need to dry clothes indoors, open the window and close the door of the room where the clothes are drying, so that moisture can escape rather than circulate around your home.
  • If you use a vented tumble drier, make sure it is properly vented to an open window or through an outside wall.
  • While cooking, bathing or washing, use an extractor fan and/or open a window, and keep the door closed.
  • Keep the extractor fan on and/or the window open for about 20 minutes after you have finished (with the door closed).
  • If your windows have trickle vents (UPVC windows have slotted vents in the window frames) open when rooms are occupied. These vents provide constant ventilation which removes water vapour.
  • If you can, put free-standing wardrobes and other furniture against internal walls, leaving a gap between the wall and the furniture so that air can circulate around the room.
  • Try not to overfill cupboards, wardrobes and drawers so that air can circulate around the contents.
  • Keep your home warm to avoid cold surfaces.
  • If you notice mould growing in your home, treat it straight away to stop it from spreading and causing more damage. Sterilise the affected area with a suitable fungicidal wash.