Home improvements

Damp and mould growth

Why do you get condensation?

Air can only hold a certain amount of water vapour. The warmer it is the more it can hold. Water vapour is cooled by contact with a cold surface such as a mirror, a window or even a wall. The water vapour will turn into droplets of water called condensation. The warmer you keep your home, the less likely you are to get condensation.

When condensation is a problem

Every home gets condensation at some time, usually when lots of moisture and steam are being produced for example when running a bath, when a main meal is being cooked or when clothes are being dried after washing. It is quite normal to find bedroom windows misted in the morning after a cold night. But if your home never seems to be free from condensation, read on.

How do you know if it’s condensation?

It’s not always easy to tell, but other types of damp such as rain or plumbing leaks usually leave a ‘tidemark’. Condensation is more often found on north-facing walls and in corners, in cupboards, under work surfaces and wherever there is little air movement.

If you’re not sure what is causing the damp problem in your home, start by checking pipes and overflows and under sinks to see if there are any obvious leaks. Have a look outside and check for missing slates, cracked gutters or rainwater pipes.

If you live in a new or recently modernised house or flat, it may not have dried out from the water used during the building work. It usually takes 9 to 18 months for this to happen and you may need to use more heat in the home during this period.

What you can do about it?

You will get less condensation if you keep your home warm most of the time. Insulation in walls and roofs will help a great deal, but with fuel prices rising try to remember the following:

• Have your heating system checked and maintained on a regular basis to ensure that it is working efficiently.
• Try to leave some background heat on through the day in cold weather.
• If you can’t afford to spend more on fuel because of high quarterly bills, ask your gas or electricity supplier about their budget schemes which will help spread the cost of your fuel.
• Make sure that you are getting all the help and benefits to which you may be entitled, e.g. Pension Credit, Child Tax Credit, Housing Benefit etc.

Improve ventilation

The more moisture that is produced in your home, the greater the chances of condensation unless there is adequate ventilation. Nobody likes draughts, but some ventilation is essential:

• In winter open windows a little, only for as long as they are misted up. If you fit draught excluding materials, leave a little space for a small amount of air to get through.
• Never block chimneys completely. If you are blocking up a fireplace, fit an air vent to allow for some ventilation.
• You will need to allow extra ventilation if you use bottled gas and paraffin heaters. Flueless heaters of this sort produce more than a pint of water for every pint of fuel they burn.
• Drying clothes indoors, particularly on radiators can increase condensation unless you allow air to circulate.
• If you have a tumble dryer which is not vented to the outside you will need to allow more ventilation when you use it.
• Don’t overfill cupboards and wardrobes and always make sure that some air can circulate freely by fitting ventilators in doors and leaving space at the back of shelves.
• Don’t allow kettles and pans to boil away for any longer than is necessary.
• If you have an extractor fan, use it when windows get steamed up.
• Keep kitchen and bathroom doors shut, particularly when cooking, washing or bathing to reduce water vapour spreading through the house.
• If you have mould growth, the chances are that it’s a result of condensation. You can get rid of mould by washing down affected surfaces with a bleach-type solution. You can buy special paints which may help to prevent it.