Damp and condensation


There can be many causes of damp and condensation in your home.

It's important to find out how and why problems are happening, so you can tackle the problem and stop it happening again.

Below is some information about what condensation is, and suggestions for small changes you can make to reduce it in your home.

  • What causes condensation damp?

    Condensation is formed when water droplets in the warm air in your home come into contact with colder surfaces, such as windows, external walls, and pipes.

    It is common to all homes, and is created by daily activities such as cooking, bathing/showering, and washing and drying clothes. If not dealt with promptly, condensation can lead to black mould appearing, which looks unpleasant and can damage clothes and furniture.

    The formation of condensation is worse in winter when there are greater variations of air temperature between indoors and outdoors. Warm humid air also allows dust mites to breed, which can make existing respiratory conditions such as asthma worse.

    Damp and black mould can make your home feel like an unpleasant place to live. Most often they are caused by condensation which you can tackle or prevent with some simple changes.

  • What is damp?

    There are several types of damp that can occur in your home.

    Condensation damp

    which generally happens when a property can't deal with normal levels of water vapour because of a lack of insulation, ventilation or heating, or a combination of all of these things.

    Rising damp

    This damp happens when moisture travels up from the ground through the bricks to the height of about one metre.

    Penetrating damp

    This damp happens when water penetrates into the fabric of a building from outside to inside, for example, because of a leaking downpipe.

  • What is mould?

    Mould is a type of fungus that grows in damp, moist conditions, often in areas with poor or low lighting and no ventilation.  It’s normal to have some mould growth in winter but it needs to be cleaned and ventilated regularly to prevent it from getting more serious. It can grow on most surfaces where moisture is present, and may sometimes grow in places you cannot usually see such as behind wallpaper and under carpets.

  • How do I reduce condensation?

    You can reduce the amount of condensation and the possibility of black mould forming in your home by following these simple steps.

    Some dos:

    • Open your windows as much as possible
    • Keep trickle-vents open at all times (if they're fitted in your home)
    • When preparing a bath, running the cold water first, before the hot, will reduce steam by 90%
    • Keep lids on pans when cooking
    • Keep ventilation fans switched on (if they're fitted in your home)
    • Keep kitchen and bathroom doors closed to stop moisture escaping
    • Ventilate your bedroom at night while you sleep
    • Keep furniture away from walls to allow air to flow around the room
    • Wipe condensation from windows and windowsills as soon as possible after it forms
    • Treat the first signs of mould with a mould and mildew cleaner

    And some don'ts:

    • Don't dry clothes on radiators
    • Don't use an unvented tumble dryer
    • Don't use bottled gas heaters (they produce eight pints of water per cylinder)
    • Don't use your gas cooker to heat your kitchen
    • Don't block permanent fans
    • Don't obstruct or block air bricks inside or outside your home
    • Don't block windows or trickle vents in any room
  • What should I do if I find damp in my home?

    Condensation damp is the most common type of damp.

    Condensation damp is not a structural problem and can usually be treated by ventilating and heating the affected area.

    It's created by daily activities such as cooking, bathing/showering, and washing and drying clothes. It tends to appear in colder weather when the walls of your house are colder than the air inside.

    Take a look at our 'How do I reduce condensation' advice above.

    Rising damp or penetrating damp

    If you find rising damp or penetrating damp in your home, we can help.
    Please get in touch by email, via myhomeonline or call 0300 1234 009.

You can also download this information as a leaflet:

Download damp leaflet