Condensation & Mould

What is Condensation?

Condensation happens when warm damp air meets a cool surface and water droplets are formed. If the cool surface is non-absorbent (e.g. window glass), the water runs down the surface. If the cool surface is absorbent (e.g. wallpaper) the water soaks in and the area becomes damp. Damp areas provide ideal conditions for mould to grow. 

Damp caused by condensation should not be mistaken for damp caused by a leaking roof or rising damp. Damp from a leak leaves a ‘tide mark’ around the source of the leak, and should be reported to us so we can repair the problem area.

How Does Condensation Happen?

Condensation in the home comes from many sources: your body loses around quarter of a litre of water each day simply through breathing; boiling kettles and cooking meals release water vapour; taking a shower and drying clothes indoors all put moisture into the air inside your home.

When this air touches something which is cooler than the air, for example, a window, behind a large piece of furniture, an external wall, etc, the moisture in the air condenses back into water.

Condensation can happen in any room but is more common in cooler rooms such as bedrooms and hallways, or in rooms where more water vapour is produced, like kitchens and bathrooms.

Dos and Don’ts for Preventing Condensation

  • Do keep your home at a comfortable and consistent temperature (at least 18 degrees Celsius is recommended)
  • Do keep your home well ventilated
  • Do keep the trickle vents in the window frame (if fitted) open. Most of our properties have trickle vents
  • Do dry your clothes outdoors whenever possible
  • Do make sure if you have a tumble dryer, it is either a condensing dryer, or is properly vented to the outside
  • Do keep lids on your pans and don’t leave kettles boiling 
  • Do keep bathroom doors closed when taking a bath or showering, and wipe down damp bathroom surfaces rather than letting them air-dry
  • Do leave a gap behind large furniture to allow air to circulate
  • Do use an extractor fan in the kitchen and/or bathroom id you have one
  • Do use thermal or lined curtains, keeping them open in the day and closed before dusk. This will capture the free heat from the sun and help to lift indoor temperatures
  • Don’t use bottled gas or paraffin heaters as they produce a lot of moisture
  • Don’t over fill wardrobes - leave room for air to circulate
  • Don’t dry clothes over warm radiators
  • Don’t cover wall vents


If you already have mould, it is important to deal with it promptly.  Wash the area with a suitable cleaning product, and then wash the area with fungicide (this can be found at any DIY shop).  Wallpaper may need to be stripped from the area before treatment. Carpets and soft furnishings should be shampooed, not brushed, as brushing will release mould spores into the air, which can sometimes be harmful to adults, children and pets. 

If you are unable to treat the mould yourself, please book a Property Officer inspection through your My Home account, or call us on 01620 825032 and choose ‘other maintenance issue’ from the phone menu.