Dealing with Damp and Condensation

During the colder months damp and condensation can become a major problem in many homes. Condensation is a form of damp which forms when warm moist air hits a cold surface and condenses, forming water droplets. Other forms of damp affecting homes include rising or penetrating damp.

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Condensation

Condensation can be a problem in any property, regardless of its age.
If left untreated, black mould can develop on damp surfaces, and looks and smells bad. It can cause health problems as well as damage clothes, furniture, books, shoes and decorations.

It can be worse in homes where ventilation and circulation of air has been reduced. Controlling ventilation and air circulation around the home is important to prevent condensation as moisture-filled air needs to escape to the outside instead of collecting inside the home and condensing on surfaces.

Rising and/or penetrating damp can also cause problems in your home, although it is less common than condensation. Further information about damp can be found at the bottom of this page.

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:

Cooking food and boiling the kettle
Baths and showers
Drying clothes inside
Unsuitable venting of tumble dryers

Areas prone to condensation

The following areas are particularly prone to condensation:

Cold surfaces such as mirrors, windows and window frames
Kitchens and bathrooms where a lot of steam is created
External walls, walls of unheated rooms and cold corners of rooms
Wardrobes/cupboards and behind furniture against an external wall

Reducing condensation

There are four main things to consider when dealing with condensation - heating, insulation, ventilation and excess moisture.

Heating

Condensation is most likely to be a problem in homes that are underheated. Try to keep temperatures in all rooms to above 15°C as this will reduce condensation forming on external walls.

Insulation

Insulating your home will have a threefold value in tackling the problem:

Warming the surface temperature of walls, ceilings and windows.
Generally increasing the temperature of the home.
Reducing heating costs thus allowing the home to be heated to a higher temperature more affordably.

Ventilation

Condensation will occur less if you allow air to circulate freely. Make sure vents and airbricks are not covered or obstructed. Whenever possible, open a window slightly when cooking or running a bath/shower.

Reducing moisture

Condensation in the home occurs when there is too much moisture in the air. Take steps to reduce the amount of moisture in the air by following some of our top tips:

In cold weather try and keep temperatures between 18-21°C in main living areas whilst indoors.
Don’t block airbricks or air vents.
Dry washing outside whenever possible.
Don’t dry clothes on radiators. This will make your boiler work harder to heat your house and cost almost as much as using a tumble dryer, whilst also creating a lot of condensation.
If you have to dry clothing indoors and don’t have a tumble dryer, place clothes on a drying rack in a room where a window can be opened slightly and keep the door closed.
No drying rack? Put your clothes on hangers and hang from a curtain pole above a slightly opened window.

Other tips to help you reduce and manage condensation in your home:

In the living room

Open window trickle vents during the day or when going out, or open windows for at least ten minutes every day.
Lay thick carpet with a good thermal underlay.
Hang thick, heavy lined curtains during the winter to help keep the room warm.

In the kitchen

Close internal doors whilst cooking and open a window.
Use an extractor fan if you have one.
Put lids on pans (this also reduces boiling times and helps save money).
Only boil as much water as you need in a kettle to reduce steam and save money.

In the bedroom

Wipe down windows with a window squeegee.
Open window trickle vents during the day or when going out, or open windows for at least ten minutes every day.
Don’t put furniture, including beds, against any external walls and try to leave a gap between the wall and furniture to allow airflow.
Lay thick carpet with a good thermal underlay.
Hang thick, heavy lined curtains during the winter.

In the bathroom

Open windows whilst bathing/washing and leave them open for
about 20 minutes after, if it is safe to do so (do not leave your home unsecured).
Use an extractor fan if you have one.
Take shorter and cooler showers.
When running a bath put the cold water in first; this results in significantly less condensation.
Wipe down windows/mirrors/tiles/shower doors with a window squeegee and mop up the moisture with an absorbent cloth which can be wrung out in the sink.
Don’t leave wet towels lying around.

Decorating

When wallpapering use a paste containing a fungicide to prevent further mould growth.
Use thermal lining paper under wallpaper when decorating.
Use mould-resistant paint on areas prone to mould such as ceilings above windows.

Dealing with Mould

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.

Rising damp

Rising damp is caused by a failed or ‘bridged’ damp proof course. This allows moisture in the ground to rise up 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:

Growing areas of damp on walls or ceilings.
Blotchy patches on walls.
Wet and crumbly plaster.
Signs of spores or mildew.
Drips and puddles.