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How condensation leads to other more severe problems

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How condensation leads to other more severe problems

By Ruth MacEachern

Product Manager

May 19, 2021

Condensation forms in your home when warm, moist air comes into contact with a cool surface and loses the ability to hold as much water vapour.  That water vapour is deposited onto the cool surface where it can either sit in the form of beads of water, or soak into the material where it can build up over time.

Some condensation is unavoidable, but in some homes, where there is insufficient air flow to allow the humid air to dissipate outdoors, condensation can build up to very high levels where it can cause damp to form and in turn, lead to mould growth that is not only unsightly, but also potentially damaging to your health.

The risks of condensation

Condensation itself is not a problem.  It can be annoying to see a build-up of water droplets on your windows in the morning, or on bathroom walls and mirrors, but these are simply the signs that condensation is there in your home.

The problems with condensation arise when insufficient action is taken to deal with it, and it is allowed to build up on porous surfaces where it can soak into material such as wood or plaster and cause damp problems.

These damp patches often form in cold corners or in places where there is little air flow such as behind furniture.  As a result, you may not be aware that they are forming until mould begins to grow in the damp and you become aware of a stale mildew smell in the affected rooms.

The damp itself can damage the fabric of your home, causing wallpaper to peel, paint to flake off and plaster to crumble.  This can mean a costly repair job to sort out the damage.

Damp patches, particularly those which are out of sight are also a place where mould can thrive.  There are many different types of household mould which spread very quickly by releasing microscopic spores into the air.  These spores are allergens, and people living in a mouldy dwelling may suffer more with allergies or respiratory problems as a result.  Some types of mould – notably toxic black moulds – can release chemicals called mycotoxins which can cause very severe reactions and lead to poor health.

Where condensation comes from and what you can do about it

Moisture is released into the air by a wide variety of the things we do in our homes.  Cooking and bathing release significant quantities of water vapour each day, but other things contribute too.  Washing machines and dishwashers, tumble driers and towels left on radiators all release water vapour.  Overnight, our breathing when asleep results in substantial amounts of moisture escaping into the air, and this is often seen on windows in the morning.

It is not possible to fully remove moisture from the air of our homes, but we can take steps to reduce it, and prevent it reaching the levels that cause condensation and damp.  The most effective thing you can do is to improve air flow with an extractor fan or ventilation system.

How ventilation helps

The risk of condensation causing damp in your home is highest in areas where the moisture has time to settle and sink into a porous surface such as wood or plaster.  Good ventilation through a house prevents static air from persistently coming into contact with cool surfaces and as such reduces the amount of condensation that can form. 

The movement of air also helps any deposited water to be reabsorbed into air that is less humid before being expelled from the building via an extractor fan.

There are different types of ventilation including positive input ventilation systems (PIV), and mechanical extract ventilation (MEV).  PIV systems work by drawing in fresh air from outside the building to displace the moist air that is already inside, while MEV systems force air out of the building to draw fresh air in from outdoors to replace it.

PIV systems and standalone extractor fans can be fitted into an existing property, while MEV systems are typically installed in new build or during major renovations due to the amount of building work that they require.

Find out more

Speak to one of our helpful local ventilation specialists today.  They can arrange a free home survey where they can use their experience to get to the bottom of your condensation or damp problem and advise on the best solution for your needs.


Need help with condensation, mould or damp problems?

One of our local experts will contact you to learn more about your problems, offer free expert advice and make recommendations for a permanent solution.

During the free survey we will

  • check Assess any condensation, damp or mould problems in your property
  • check Take readings of the relative humidity levels
  • check Identify any underlying problems and make recommendations for a permanent solution

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