Damp and condensation in your home

Damp and condensation often get confused as they have similar symptoms but the causes of the two problems are very different.

Damp due to disrepair

Dampness can be caused by water entering your home from the outside. This will be caused by:

  • Leaking pipes, wastes or 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 where there isn’t a damp course or where the outside ground level is higher than the damp course

This form of damp is different from condensation because the cause of the damp tends to leave a tidemark and it will be much wetter nearer the source of the problem.

In all instances of damp caused by disrepair, we will carry out the necessary repairs to ensure that the defect causing the problem is corrected. Please contact our Technical Services Advisors on 0300 500 6262 or email the repairs team to report the problem.

If you do not think the damp comes from any of these causes, you probably have condensation forming inside your home.

What is condensation?

The air that we breathe contains water vapour and warm air holds more water vapour than cold air. Condensation forms as tiny droplets of water when warm air comes into contact with a colder surface.

We tend to notice condensation most on windows on a cold morning but it can also be seen on mirrors after a bath or shower and on colder surfaces such as tiles and external walls. Condensation can get worse in areas where there is little air movement, for example in the corner of a room or behind furniture.

Typical symptoms of condensation

  • Mould growth on walls and behind furniture
  • Mildew on clothes and other fabrics
  • Pooling of water on window boards
  • An increase in house dust mites

Condensation is not caused by a fault with your home but by the amount of water vapour created in your home.

The way your home is ventilated and heated also affects condensation. All homes of all ages can and will suffer from condensation to some degree at some time.

Managing condensation

The key to managing condensation is about getting the right balance between moisture in the air and heating and ventilating your home, so that you can keep condensation to a minimum.

Changes in temperature, lots of moisture and no ventilation will cause more condensation to form. Having a more constant temperature, reducing moisture and having good ventilation will reduce condensation.

To find the right balance for your home you must:

  • Manage the amount of moisture you and your family add to the air in your home
  • Ventilate your home to allow moisture in the air to escape
  • Heat your home to minimise the temperature difference between the air in your home and the coldest surface

Moisture in your home

Everyday living adds extra moisture to the air inside your home, even breathing contributes to the amount of water in the air. One sleeping person adds half a pint of water to the air overnight and twice that when active in the day.

Two people at home (breathing) 3 pints
One bath or shower 2 pints
Drying clothes indoors 9 pints
Cooking and using a kettle 6 pints
Washing dishes 2 pints
Bottled gas heater (used for 8 hours ) 4 pints
Total moisture added in 1 day 26 pints

Your home cannot cope with this additional water being continually added to the air without condensation forming. The water you and your family adds to the air can be easily reduced if you:

  • Hang your washing outside to dry if at all possible, or hang it in the bathroom with the door closed and the window slightly open or an extraction fan on. Do not put washing on radiators or in front of radiant heaters
  • If you use a tumble drier, make sure it is vented to the outside or that it is the new condensing type
  • Always cook with pan lids on and turn the heat down once the water has boiled. Only use the minimum amount of water for cooking vegetables
  • Do not use your gas cooker to heat your kitchen as burning gas produces more moisture (you will notice your windows mist over)
  • Do not be tempted to use bottled gas or paraffin heaters, as they produce higher levels of moisture
  • When filling your bath, run the cold water first and then add hot, it reduces steam (which leads to condensation) by 90%

Ventilating your home

To keep condensation at bay it is essential that you ventilate your home to enable the moisture rich humid air to escape and allow fresh air in:

  • Reduce the condensation that builds up overnight by cross ventilating your home. You can do this by opening a small window downstairs to the first notch and a small one upstairs. These should be on opposite sides of the house and diagonally to the opposite if you live in a flat. At the same time, open the internal doors, as this allows drier air to circulate. Do this for approximately 40 minutes each day.
  • Ventilate your kitchen when cooking, washing up or washing by hand. A window slightly open for a long period is as good as a window wide open for a short period. If you have a cooker extraction hood or extraction fan use it to remove steam before it circulates throughout your home.
  • Ventilate your kitchen and bathroom for about 20 minutes after use by opening a small top window. Use an extraction fan if possible, they are cheap to run and very effective. Keep kitchen and bathroom doors closed when in use to prevent moisture escaping into the rest of the house.
  • Ventilate your bedroom by leaving a window slightly open at night or use trickle ventilators if fitted. Reduce the risk of mildew on clothes by allowing air to circulate around them. You can do this by leaving a small gap between large pieces of furniture and where possible place wardrobes and furniture against internal walls not external walls.
  • Never overfill wardrobes and cupboards as it restricts air flow. Do not push beds and sofas against outside walls which are always colder and attract condensation. Make sure there is a 9 inch (225mm) gap. Bedding can get damp if air cannot circulate around it.
  • Please note: Do not over ventilate your home in cold weather as this will reduce the temperature inside making condensation more likely as well as increasing heating costs. Remember that it is about creating the right balance for your home.
  • Please ensure you close windows securely before you go out.

Heating your home

By keeping your home warm you will also warm the walls and surfaces of your home. A combination of warm air and warm surfaces will allow more moisture to stay in the air within your home and will reduce the extent of condensation you experience:

  • If possible try to keep your home at a constant temperature rather than heating your home from cold twice a day
  • Heating one room to a high level and leaving other rooms cold makes condensation worse in the unheated rooms. It is better to have a constant level of heat throughout your home
  • If you don’t have heating in every room, open doors of unheated rooms to allow some of the heat into them
  • Do not use paraffin or bottled gas heaters as these also produce water which will add to the level of moisture in your home
  • Do not push beds or sofas against radiators as this prevents efficient circulation of warm air

Striking the right balance

Getting the balance right for you and your home is an ongoing process. During this process you will experience some form of condensation and you will have to take action to stop the condensation becoming a problem.

When condensation occurs wipe your wet windows and window boards every morning, as well as any wet surfaces in the kitchen or bathroom. Wring out the cloth and dry it outside rather than drying it on a radiator.

If condensation is left untreated mould may develop. To kill and remove mould;

  • Wipe down or spray walls and window frames with a fungicidal wash that carries a Health and Safety Executive (HSE) approval number and follow the instructions carefully for safe use. You can often buy these in supermarkets
  • After treatment, redecorate using a good fungicidal paint and a fungicidal resistant wall paper paste to help prevent mould growth recurring. It should be noted that the affect of fungicidal or anti-condensation paint is destroyed if covered with ordinary paint or wallpaper
  • Dry-clean mildewed clothes and shampoo any carpets. Do not try and remove mould by using a brush or vacuum cleaner

Further assistance

If you require further guidance about how to deal with condensation in your home you can contact our Technical Services Advisors on 0300 500 6262 or email the repairs team to arrange for a Maintenance Inspector to call.

Our Inspectors can measure temperature and humidity levels within your home to confirm if the problems you are experiencing are due to condensation.

In all reported cases we will also arrange for our heating engineers to check your heating system to ensure it is working properly and in some cases our Maintenance Inspectors may also recommend that additional ventilation is installed to help you to reduce moisture in your home safely.