Walls and floors which are damp will be colder than dryer structures. This will make it more difficult to heat, increasing the fuel/energy required to heat a property.
The structural damage caused by dampness and rot may become a safety risk, and any resulting mould or fungal growth may adversely impact on the respiratory system of the occupants.
Main causes of dampness or ingress of water into a property are:
- Penetrating Dampness - water/rain seeps in through a defective part of the structure such as a wall, roof or chimney.
- Rising Dampness - Moisture seeps up through the floor and walls by capillary action where there is a defective damp proof course or no damp proof course exists.
- Leaking pipes - a defect in a water or drainage pipe, may be leaking internally.
Condensation dampness
This occurs when warm and humid air in a home meets a colder surface and condenses to form dampness or water droplets. Warm air can hold onto more water vapour than cold air so when it cools down it can’t retain the same amount of water vapour and condenses.
The dampness formed can damage the surface of the wall, but more often, mould spores will grow here due to the moist surface. If condensation keeps on occurring in the same place, it can cause black mould growth. This mould can grow on any surface – fabrics, furniture, clothing or other stored items.
Tenants living in homes with damp and mould may be more likely to have respiratory problems, allergies, asthma, and other conditions that impact on their immune system therefore it is important that these issues are addressed when they arise.
Condensation and mould growth can be managed by following this advice:
If your property is affected by dampness follow these tips to reduce the risk of condensation dampness and mould forming by following these tips:
- Clean any existing mould growth by wiping the affected surface with a cloth and mould cleaner - you don't want to over-wet the surface or damage the finish/paint. Use a proprietary mould killer and cleaner as these are likely to be more effective than other cleaning products.
- Produce less moisture: Easy wins are putting lids on saucepans, use of mechanical extraction when cooking and taking showers, use of a condensing clothes dryer or drying clothes outside or inside a well-ventilated room with the door closed. Avoid drying cloths on radiators were possible.
- Avoid the use of bottled gas heaters.
- Ventilate to remove moisture: Easy wins are opening windows in kitchen, bathroom & bedroom after use, move furniture away from walls, air cupboards.
- Heat properties: Ideal temperature range between 19-22 degrees Celsius
- Insulate building: 270mm loft insulation and secondary or double glazing
- Landlords can refer to British Standard 5250:2002 Code of Practice for control of condensation in buildings
- Paint affected walls with an antifungal treatment which can prevent the further regrowth of mould.
- Keep external cold walls free from furniture – sofas, wardrobes etc., so air can move freely around the wall which will help reduce the possibility of mould growth as a result of condensation.
The Chartered Institute of Housing (CIH) have also recently produced and animation video and guidance document entitled “Maintaining Healthy Homes – A Guide to Preventing and Resolving Damp and Mould”. This information can be found at the following link:
https://www.cih.org/publications/maintaining-healthy-homes-a-guide-to-preventing-and-resolving-damp-and-mould/