Most people’s first instinct when dealing with mould is to clean it away. But although it’s possible to scrub mould from walls and tiles, this is only a temporary solution unless more is done to stop it returning.
Painting over the mould is also ineffective in the long term. Getting rid of mould permanently means removing the conditions that encourage it to grow.
There are four recommended steps for tackling damp and mould - and making sure they don’t return.
Step 1: Tackle sources of dampness around the building:
Check the building for a damaged damp course, rising damp or roof and window leaks where water may enter the home.
Step 2: Improve ventilation
It is vital to provide methods to remove moisture from indoor spaces. This means installing extract fans in kitchens and bathrooms, and providing occupants the usable means to ventilate the whole home.
It is important to consider ventilation for areas such as bedrooms since mould is often found here. People exhale moisture as they sleep, and if the bedroom has a closed door and windows, this can quickly build up. Trickle vents on windows are helpful, but may not be installed as standard on older homes. Ventilation is vital because it removes moisture and other indoor pollutants, which can lead to mould.
Step 3: Improve heating
One of the factors in the formation of condensation is that warm, damp air touches cold surfaces, releasing moisture onto the surface. Removing the damp from the air is one important step, but increasing the indoor temperature is also crucial to preventing mould. Warming surfaces such as walls and windows reduces the conditions for condensation to form.
Improving warmth in homes can include improving insulation levels. But it is vital to ensure that this does not have unwanted side effects. For example, part F of the Building Regulations5 which deals with ventilation, notes that many existing homes are ventilated through ‘infiltration’. This is the exchange of air between the inside and outside of a building through gaps and cracks. Energy efficiency measures that reduce this infiltration will leave the home ‘under-ventilated’.
For example, loft or wall insulation improvements or new draught-proof windows will keep a house warmer and save energy, but the extra insulation can also trap moisture indoors, increasing the likelihood of mould. Therefore, if insulation is added to an existing property, ventilation must also be considered as part of the refurbishment. Research shows that people living in well-insulated and adequately ventilated homes are less likely to visit their doctor or be admitted to a hospital due to respiratory conditions than those living with damp.
Step 4: Make a home that people can live in
We must acknowledge that people living in homes use showers and cook food. They also need to dry clothes in cold and wet weather. Landlords must make provision for the moisture that is produced from these activities.
Too often, tenants are asked to ‘cut back’ on normal household activities, such as taking shorter showers or only drying clothes in a tumble dryer. However, there are limits to what can be done - even short showers in a cold home will produce excess moisture, and householders may feel that operating a tumble dryer is expensive.
While householders have a responsibility to reduce moisture in the air as much as they can, it’s also crucial for landlords to make the link between low indoor temperatures, poor ventilation and long-term dampness. Without usable and affordable ventilation and heating systems in place, there is little that occupants can do on their own to improve conditions. Some are driven to buy products which seem to provide a solution, such as ‘films’ or dehumidifying bags that claim to reduce condensation on windows. At best, these work briefly, addressing a symptom but not the problem. Preventing excessive moisture and the mould that can result from it needs a whole-home approach that addresses damp and mould sources along with adequate and affordable ventilation and heating.
For more guidance on dealing with mould in your your home, A Practical Guide to Mould & Damp Prevention in New and Existing Homes is available to download for free. This guide from BESA and Mitsubishi Electric highlights how landlords can tackle the problems of damp and mould at the source with straightforward steps to improve the indoor environment.