How to tackle condensation, damp and mould

Author: Richard Vale 26/04/2017

See how you can tackle condensation, damp and mould in the latest blog from Richard Vale, our Households and Communities Project Officer.

The wet weather during winter and spring months in the UK is a leading cause of condensation and damp, which, if left untreated, can lead to mould. Damp and mould can rot timber frames and furniture, spread across curtains and upholstery and cause structural damage for your household. Further, they can pose a serious risk to your health. According to the NHS, damp and mould present in your home means you are more likely to suffer from respiratory illness, allergies and asthma. This is especially true if there if someone in the property is a baby or child, elderly, or already has pre-existing health problems.

It is therefore important to tackle condensation at its earliest stages and following the four simple steps below should reduce the levels of condensation in your house and prevent mould growth.

Minimise moisture

People create moisture. Cooking, showering, boiling the kettle and even breathing all create moisture. It’s even estimated that four people living in a three bedroom house can create over 100 pints of moisture a week just from these daily activities. Reducing moisture can be as simple as keeping lids on pans when cooking and drying clothes outdoors. If you can’t dry your clothes outdoors, keep them in the kitchen and close the door to the rest of the house (and keep a window open) to avoid the damp air spreading through the house. You should also check all your appliances and pipes for leaks and, if you have a tumble dryer, make sure is properly vented to the outside.

If you have persistent problems a dehumidifier might be a worthwhile investment, however, it should generally be the last measure you take to tackle excess moisture.

Boost ventilation 

Cold weather means more time spent indoors with the windows shut, this means more moisture is being produced, less damp air is leaving your property and less dry air is entering. Despite the cold weather it is important to make sure there is airflow in your property. This means opening windows in occupied rooms for a small amount of time, for example bedroom windows for 15 minutes each morning. The bathroom and kitchen are particularly susceptible to excess moisture so make sure to open a window after showering and during cooking. If you have an extractor fan in either room, turn it on while you’re in the room and for some time after.

In the living room and bedrooms you should make sure to leave a small gap between the walls of your home and the furniture to allow the air to circulate to stop air condensing on the walls. Similarly, overfilled wardrobes and cupboards are breeding grounds for mould as the trapped warm air inside is not able to circulate.

Increase insulation

Double glazing, cavity wall insulation, loft insulation and draft proofing will help to reduce the heat loss from a property and warm homes suffer from less condensation. The current standard for loft insulation is 270mm so even if there is some up there, it could be worthwhile investing in a top up. For loft and cavity wall insulation, Energy Company Obligation (ECO) funding is available depending on the property age and level of current insulation. Draught-proofing around windows and doors will prevent air travelling around your house. You also need to make sure your windows are properly insulated, secondary glazing is a cheaper alternative, or addition, to double glazing.

In some exceptional circumstances, cavity wall insulation may be the cause of damp, see penetrating damp below. If you’ve tried all the suggestions in this post and nothing’s worked, and your home is exposed to wind-driven rain, it may be worth investigating whether damp is coming in through your walls.

Consistently Heat

During the winter, and other cold spells, you should try to maintain a constant temperature in your home, somewhere between 18°C and 21°C. This is because warm air only releases moisture once it has found a cold surface to settle, so making sure the house is the same temperature throughout can prevent quick forming condensation. Keeping your heating on a low level for a long period will gently warm your household, reducing the cold surfaces where warm wet air condenses.  If you have rooms which you seldom visit and want to save money by not heating them, make sure to keep the doors to these rooms closed. Alternatively, set the thermostatic radiator valve in these unoccupied rooms to 1 to allow the room to be heated at minimal expense.

Mould Removal

If you already have mould on your walls and ceilings then you need to clean it off properly as it only takes a small amount of mould to quickly multiple and undo all your hard work. The NHS recommends only tackling mould that covers an area of less than one meter squared and that you should protect yourself by wearing goggles, long rubber gloves and a mask that covers your nose and mouth. It’s also advisable to open the windows but keep the doors of the room shut to avoid mould spores spreading to other parts of your house.

To tackle the mould, use a cloth soaked in warm water and a mild detergent, such as washing up liquid, clothes washing powder or heavily diluted bleach, to carefully wipe away the mould. Next use a clean dry cloth to remove any lingering moisture and apply an anti-fungal spray. After the mould removal, all surfaces and floors in the room should be thoroughly cleaned. Any soft furnishings or clothes should be professionally dry cleaned or replaced. If you have an area with repeated mould issues, applying mould-resistant paint after the cleaning process could prevent further growth.

Other causes of damp

Although condensation is one of the main drivers of damp, there are two other potential reasons behind moisture entering your home:

‘Penetrating damp’ is caused by leaking pipes, a damaged roof, or faulty seals around doors or windows. Damp and discoloured marks, damaged plaster, rotting skirting boards and localised dampness can identify penetrating damp. The building defects behind the damp can should easily be repaired by a competent builder or plumber.

‘Rising damp’ is due to moisture in your walls as a result of water in the ground underneath rising up through the walls. This is often caused by a defective (or non-existent) damp course in the property. This rising damp will leave a clear ‘tide mark’, a yellow or brownish stain line around one meter above the floor. A qualified builder is generally required to fix the issue.

Further information:

NHS damp and mould removal and health impacts.