Condensation, damp and mould

What is condensation?

When warm moist air produced by ordinary household tasks such as cooking and bathing hits a cold surface (for example a cold wall or a window), condensation occurs. Unless the moist air can escape to the outside through an open window, air vent or extractor fan, it will always stay in your home moving around until it finds a cold spot where it can condense.

Condensation can cause dampness and mould growth in your home. This looks unpleasant and can increase the risk of respiratory illness. 

Is it condensation?

Condensation is not the only cause of damp. It can also come from:

  • Leaking pipes, wastes and overflows
  • Rain seeping through the roof where a tile or slate is missing, spilling from a blocked gutter, penetrating around window frames, or leaking through a cracked pipe
  • Rising damp due to a defective damp-course or because there is no damp-course
    • These causes of damp often leave a ‘tidemark’
    • If your home is newly built it may be damp because the water used during its construction (for example, in plaster) is still drying out
    • If you do not think the damp comes from any of these causes, then it is probably condensation

Last updated: ‎16‎/‎03‎/‎2020‎ ‎12‎:‎01‎