Keeping your home free from damp and condensation

Is your home damp?

Damp is generally caused by a fault in the structure of the building. There are two basic types of damp:

  • Penetrating damp happens when water enters your home through an external defect, e.g. a crack in a wall or loose roof tile.  This damp will often show as dark patches on walls and ceilings which get worse when it rains.
  • Rising damp occurs when there is no damp course or there is a problem with the damp course or membrane and water rises from the ground into the walls or floor.  Symptoms of rising damp are a tide mark of up to 1 metre above the floor with peeling wallpaper and crumbling and salt stained plaster.  Skirtings and other timbers may also show signs of rot.

These causes of damp rarely have black mould and often leave a ‘tidemark’.

If you do not think the damp comes from any of these causes, it is probably condensation.

What is condensation?

Condensation occurs at any time but is most noticeable during cold weather.  It starts as moisture in the air; usually produced by cooking, washing or drying clothes indoors on radiators. When it hits cool surfaces such as walls, mirrors, wall tiles and windows it condenses and forms water droplets. The moist air rises when it is warm and often ends up on ceilings and in upstairs rooms which are cooler than the rest of the house. Condensation can be found in corners, on or near windows, in or behind wardrobes and cupboards.

Persistent condensation can result in mould growth which will show up as patches of black spots on walls and ceilings.

Preventing condensation

Produce less moisture:

  • Cover saucepans
  • Dry clothes outdoors
  • Ventilate your tumble dryer to the outside
  • Avoid using paraffin or flue-less bottled gas heaters

Ventilate to remove moisture:

  • Ventilate all the home, especially when someone is at home
  • Increase ventilation of the kitchen and bathroom when in use and shut the door
  • Ventilate cupboards and wardrobes
  • Do not block permanent vents
  • Keep ‘trickle’ ventilators open as much as possible

Heat your home a little more:

  • If possible, keep low background heat on all day, with background ventilation

If you are having difficulty with heating bills contact your energy supplier about alternative tariffs.  Further information and advice can also be found on our household energy savings and energy efficiency webpages.