Damp
During the colder months damp and condensation become problems in many British homes. Learn to spot the different types of damp in your home.
Condensation is caused when warm, moist air hits a cold surface such as a window or external wall and condenses, running down the cold surface as water droplets. If left this can develop into black mould which looks and smells bad and can cause health problems as well as thousands of pounds worth of damage to clothes, furniture, books, shoes and decorations.
Condensation can be a problem in any property no matter its age. It is often worse in homes that have been modernised as ventilation and the circulation of air is reduced. Controlling ventilation and air circulation around the home is very important in the prevention of condensation because this allows moisture-filled air to escape to the outside, preventing future problems inside your home. Rising or penetrating damp can cause problems in your home although it is less common than condensation.
Rising damp
Rising damp is caused by a failed or ‘bridged’ dampproof course. This allows moisture in the ground to rise up through the ground floor walls of your home, sometimes to a height of one metre. You can usually identify rising damp because it is often associated with a tide mark at the edge of the area of damp caused by salt deposits.
Penetrating damp
Penetrating damp is classed as any water that finds its way inside from the outside. It can occur at all levels of the building and is usually higher up. Overflowing gutters, missing roof tiles, leaking pipes and downspouts, badly fitting windows/ doors and damaged pointing, cladding or flashing or render as well as covered air bricks can all be a source of penetrating damp.
Typical signs of penetrating damp are:
- drips and puddles
- growing areas of damp on walls or ceilings
- blotchy patches on walls
- wet and crumbly plaster
- signs of spores or mildew
Condensation
Condensation can cause mould to form in your home, lead to staining/ damaging wallpaper, wall surfaces, window frames, furniture and clothing. The mould and its spores carry the musty smell that is often associated with a damp house. Black mould can’t grow where salt deposits are present (as with rising damp) and is therefore a sign of condensation
Water vapour is generated in your home in many ways but the main causes are:
- steam from cooking and boiling the kettle
- baths and showers
- drying clothes inside
- unsuitable venting of tumble dryers
The best way to deal with mould is to remove it from walls using a special fungicidal wash which should be used in line with the manufacturer’s instructions. Special paints are also available that will delay the return of the mould, but unless you take steps to reduce condensation it will eventually grow back.