How To: Prevent Damp and Condensation


Drying clothes

Hanging wet clothes on radiators increases the moisture in the air which then flows around the house, collecting on cold surfaces and contributing to the growth of mould. To avoid this, dry clothes using a tumble dryer if provided, on a portable heated plug-in airer with a cover or on any airer in a well-ventilated space with an open window or dehumidifier to draw moisture in from the air.

Air needs to flow, even in cold weather

The average person breathes out approximately two litres of water every 24 hours and an average family of four will generate nearly 14 litres of water a day during cooking, washing, drying clothes and bathing.

Historically this vapour would have naturally escaped, however measures such as double glazing and insulation now trap that moisture inside the house. External windows and trickle vents need to be opened regularly to allow fresh air to circulate. Without opening windows moisture builds up and creates mould on cold surfaces like walls.

Likewise, if furniture is placed directly against walls or radiators, or if cupboards or wardrobes are solidly packed with possessions air is prevented from circulating, contributing to damp conditions.

Heating systems

The World Health Organisation Guidelines for Indoor Air Quality: Dampness and Mould (See more informtion) recommends keeping rooms between 18c – 20c. Having heating regularly on, even at a low temperature, helps to prevent damp and mould. For any advice on thermostats or heating controls, speak to your letting agent

Make use of extractor fans provided

Running a hot shower or bath, or boiling water for cooking creates steam and additional moisture in the air which circulates and collects on cold surfaces around the house. Putting an extractor fan on where provided, throughout and following showers and cooking creates a vacuum effect. Moisture is pulled out of the air into the fan and released outside through vents or pipes. If you need any advice or adjustments to extractor fans speak to your letting agent.

Use a dehumidifier

A dehumidifier pulls moisture in from the air, thereby reducing vapour and dampness that is generated by, for example drying clothes. Portable dehumidifiers are widely available at different price points through online and high street retailers.

Add plants to lower humidity levels

Several groups of houseplants have characteristics that help to reduce humidity levels including the peace lily, ferns, orchids, palms and spider plants.

Remove pooling moisture to prevent build up

It is important to note that any condensation or surface dampness that collects on windows or walls, should be wiped with a clean cloth or towel daily. This will minimise the subsequent appearance of any black mould.

Check for penetrating damp

If you see evidence of leaks from plumbing or from a damaged roof, chimney or guttering which is causing water supply to penetrate the property or repeatedly flow against walls, contact your agent. Repairs should be dealt with promptly to prevent more complex damage occurring. While waiting for the repair, limit any internal impact by drying surfaces and collecting leaks in a bucket or other container.


It is very common for mould spots to appear in houses around windows and in bathrooms and kitchens where increased water is circulating and gathering during washing and cooking.

Occupiers should dry any wet surfaces regularly and treat signs of mould either with mould and mildew cleaning products which are widely available from supermarkets and household retailers or with a white vinegar based DIY treatment.

Wear a face mask to prevent the inhalation of spores, take care to ventilate the room and protect your skin and follow manufacturers’ instructions for any commercial cleaning products.

Alert your letting agent if you have concerns. Sometimes there may be a previously unknown defect in the building which the Landlord can then address and they can review whether trickle vents are operating effectively

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