Condensation Solutions

Whole-house Ventilation: This unit (ABOVE)from EnviroVent (0845 272 7807; envirovent.com) is designed to cure condensation and mould by introducing fresh filtered air (see blue arrows) into the home at a continuous low rate. The moisture-laden air is diluted, displaced and replaced, reducing the relative humidity.

How to Spot Condensation

The most common symptoms of condensation include:

• Mould growth, usually black but not in all cases, typically appearing in corners of rooms, on window reveals or behind large items of furniture, such as beds and wardrobes
• Damp areas can appear on walls – often in the upper corners and in particular cold spots – and water droplets may be visible too
• Wallpaper can start to peel
• In serious cases, plaster and paint can begin to deteriorate
• Fabric in the room, such as clothes in the wardrobe or soft furnishings, can be prone to mildew
• Damp patches – that can look very similar to rising damp – may appear at the junction between wall and floor in ground floor rooms
• Moisture can be seen on wall tiles, mirrors and windows

Causes Checklist

Before deciding on how to treat the condensation problem in your home, you should check that:

• Your walls are not suffering from rising damp — a damp wall is a cold wall and so prone to condensation. Ensure there is a DPC or that the existing one is not bridged or damaged
• Wall cavities are clear of debris, which can build up over time
• Airbricks are clear. You could also consider fitting additional airbricks under suspended floors. Older buildings often have no airbricks, so consider fitting them if there are suspended floors
• The roof is sound and that all guttering and downpipes are carrying water away successfully
• Solid floors are not damp — the damp-proof membrane may need replacing
• There are no leaking water pipes or tanks in the house

Quick and easy fixes

Experts vary in their opinion of the effectiveness and suitability of dehumidifiers when it comes to solving the problem of condensation, but they are many people’s first port of call. On the one hand, units can be useful in removing a surprising amount of water from the air. Air is drawn in, passing over cold coils similar to those on a fridge. The cold coils cause the water to condense, and the water drips down into a bucket, which needs to be emptied regularly. The air is then reheated to room temperature and blown back out. Domestic systems are available, fitted with a humidistat that detects the amount of moisture in the air and switches the unit off when not needed. However, they can be bulky and, depending on the model you need for the size of your house, expensive to buy and run in the long term. They can also be rather noisy.

You could also: open windows after bathing or showering; dry clothes in a cool area of the home and ventilate any rooms in which wet clothes are hung out; install some form of ventilation, e.g. extractor fans; keep furniture away from the walls to allow air to flow freely around the room; ensure loft insulation is not blocking the gap between facia boards and the house wall, or any purpose-made vents; ventilate tumble dryers externally; install trickle vents; and ensure your heating is thermostatically controlled.

Redistribution of air: EnviroVent’s Multiple Input Ventilation (MIV®) loft unit (ABOVE) supplies fresh filtered air via multiple inputs into areas with a greater need for ventilation, such as kitchens and bathrooms.

Further reading:

• How to Solve Condensation
• Passive Ventilation
• Solving Damp