Wondering how to stop condensation on your windows, walls and elsewhere in the home? Read on to find out what causes this issue and learn how to stop it once and for all!

As outside temperatures drop, how to stop condensation from affecting your windows should become a priority if you want to avoid it damaging your home.

So what causes condensation? Basically, air contains moisture, but the temperature of the air determines how much moisture it can hold, and warm air contains more moisture than cold air. When warm, moist air comes into contact with either a surface or air that is colder than it is, the warm air is unable to retain the same amount of moisture as it did and that water is released either into the cold air or onto the colder surface, causing condensation to form, quickly followed by mould.

The key to stopping condensation lies in controlling humidity, improving ventilation and ensuring your home is well insulated. Day-to-day activities like cooking, washing and drying clothes, heating and even breathing produce water vapour. Air can only hold so much moisture in the form of an invisible vapour, no matter what temperature it is.

When air contains more moisture than it can hold, it reaches ‘saturation point’ and when this is reached, the moisture turns back into water and condensation occurs. The temperature reached at saturation point is called the ‘dew point’. When this happens, the air has a relative humidity of 100%. But what is normal humidity in a house? Air in the majority of homes tends to have 50 – 70% relative humidity. Problems occur when structural defects in a building mean the moisture content has become too high; when old houses have no damp-proof course; or when there’s inadequate ventilation in the home.

While condensation is obviously not great to look at, it also causes a whole host of other problems homeowners need to be aware of including:

• Damp walls where paint and wallpaper can peel;
• Mould forming on walls, window sills, soft furnishings etc;
• Risk of rotting and structural decay; and
• Potential health issues, especially for the young, elderly and anyone suffering from respiratory issues.

There are three basic ways to banish condensation from your home once and for all.

Control relative humidity in your home. Fit the best bathroom extractor fans you can find and don't forget good kitchen extraction either. Shutting the doors to these rooms whilst the extractor fans work also helps.

Ensure there’s adequate ventilation. Trickle vents in windows work well, but more sophisticated options include mechanical extract ventilation units. These replaces the air in your home by taking the stale, damp air outside, then bring fresh air back in via a separate grille, passing it back over the heat exchanger to be warmed. It’s also possible to buy central extract systems which connect all of the wet areas in your home to a central fan before discharging the stale, moist air outside.

You could also consider positive input ventilation. These systems work by supplying fresh, filtered air into your property from a unit installed in the roof cavity and a distribution diffuser mounted in the ceiling. The continual supply and slight positive pressure results in the air being continually diluted, displaced and replaced to create a healthier indoor air quality.

Upgrade your insulation. Internal walls should be kept at a temperature above the dew point of the air inside in order to prevent condensation on walls. Internal Wall installation is best when it’s not possible to add external insulation to your property.

There are also behavioural changes you can make that reduce condensation without making significant changes to your home.

These include:

• Using a range hood for ventilation when cooking in the kitchen;
• Using lids for pans;
• Limiting significant temperature changes caused by turning your heating on and off;
• Drying clothes in well-ventilated spaces (outside if possible);
• Not hanging wet clothes on heaters to dry;
• Ensuring extractor fans are on when using a bathroom or open a window; and
• Leaving a gap between furniture and walls to allow air to circulate from the base of walls.