Following the recent news released by the National Audit Office that 98% of homes with external wall insulation installed under certain schemes could have problems that will lead to damp and mould if their installation issues are not addressed, Nicholas Donnithorne, UK Technical Manager, Peter Cox, has shared his advice on addressing condensation, mould and penetrating damp issues in homes.
Nicholas said: “Spotting a damp patch or mould in your property can understandably be cause for concern and should never be ignored. Fortunately there are some simple steps you can take to address two of the most common causes of damp and mould in homes, penetrating damp and condensation.
“Penetrating damp is produced by moisture that enters the house through wind-driven rain, flooding, or defects in the building structure. This is particularly true of solid (rather than cavity) wall properties. Common ways this can occur is through porous brickwork or render, cracked pipework, blocked guttering, gaps around window frames, or cracked rendering and brickwork. Thankfully, it can often be remedied through actions such as clearing out gutters and drains, particularly after stormy weather.
“Condensation is often the root cause of mould growth indoors. Condensation occurs when warm, moist air comes into contact with cold surfaces like a wall, window or mirror and condenses into a liquid state. Everyday activities such as bathing and showering, cooking and drying clothes inside, can all increase humidity levels inside the home. With poor ventilation, condensation can lead to black mould which thrives in poorly ventilated environments.
“My top tips for helping to prevent problems associated with damp and condensation in your property are:
- Ventilate daily: Even in winter, open windows for 5-10 minutes each day to allow stale, moist air to escape and fresh air to circulate. Cross ventilation (by opening windows on opposite sides of the house) is an effective way of reducing condensation. Use the trickle vents on windows or keep a quarter light open for background ventilation.
- Use extractor fans: Always use extractor fans (where fitted) in kitchens and bathrooms when cooking or showering, and ensure they are properly maintained and, ideally, vented to the outside, rather than through a roof void. It is important to understand if your cooker hood filters and recirculates or is vented to the outside.
- Manage indoor humidity: Put lids on saucepans when cooking, avoid overfilling kettles and keep bathroom and kitchen doors shut during use to prevent moisture from escaping to other areas of the building.
- Avoid drying clothes on radiators – this blocks the heat and prevents the air from circulating. It also releases large amounts of water vapour into the home as the clothes dry, which can lead to condensation. Dry clothes outside whenever possible, though if you must dry clothes indoors, use a drying rack or airer in a well-ventilated room. Try to ensure that there’s a window ajar or extract on.
- Wipe away condensation: clean windows and mirrors daily if they fog up to avoid letting moisture sit and wring the damp cloth out in a sink, so the water does not evaporate off into the room.
- Maintain consistent heating: Keeping your home at a consistent, moderate temperature helps to prevent cold spots where condensation can form. Avoid turning the heating off completely for long periods.
- Clear blockages: Ensure air bricks and trickle vents are clear and not blocked by furniture or insulation, allowing continuous airflow. If an extractor fan inlet grill will not hold a postcard or toilet tissue up, the unit requires cleaning or servicing.
- Fix any leaks or cracks – these can allow moisture to enter your home, which can lead to damp and condensation. If you find any leaks or cracks, fix them immediately.
- A dehumidifier may help – but only in cases where the humidity is not excessive. This is achieved by drawing in air and removing the moisture, helping to prevent mould and mildew growth in the home.
- Insulate your home – properly insulating your walls and loft will help to keep the heat in and can prevent condensation from forming, as this prevents cold spots and increases air temperature.
“If you do encounter mould in your property then cleaning it properly is key, but the underlying cause of the dampness must be addressed too or it will inevitably return.
- Biocidal cleaners are most effective: look for those with a Health and Safety Executive (HSE) registration number to ensure they’re proven to work.
- Bleach-based products: can be used to remove mould stains, but a separate biocide will provide longer-term protection.
“If you think that the damp problems you are encountering in your home may be due to faulty external wall insulation, then try to seek assistance from your landlord or the property’s owner. If this work was undertaken as part of one of the Government schemes, you should already have received a letter from Ofgem, but you can also visit: https://www.gov.uk/guidance/what-to-do-if-you-have-poor-quality-wall-insulation.”
