Condensation occurs when warm moist air meets a cold surface. The air cools and releases its moisture as water droplets on walls, windows and ceilings. It is the most common cause of damp and black mould in UK homes and is particularly prevalent in autumn and winter when heating is on and ventilation is reduced.
The most visible sign of condensation is black mould growth on walls and ceilings, particularly in corners, behind furniture and around windows. Water droplets on windows, damp patches on external walls and a persistent musty smell are also indicators of a condensation problem.
Effective condensation control involves improving ventilation and reducing moisture levels inside the property. Treatment options include positive input ventilation systems, mechanical extractor fans in kitchens and bathrooms, passive air vents and specialist anti-condensation coatings. In some cases a combination of measures is required for effective long-term control.
Positive input ventilation is one of the most effective treatments for condensation. A unit installed in the loft space gently introduces fresh filtered air into the property, diluting and displacing the moist internal air and creating a positive pressure that prevents moisture build-up on cold surfaces.
Black mould caused by condensation requires specialist treatment with fungicidal solutions to kill existing mould spores and prevent regrowth. Treating the mould without addressing the underlying condensation problem will result in recurrence. A professional survey identifies the cause and the most effective treatment for each property.