Condensation Problems and Solutions

How to Overcome Condensation Problems and Solutions

The process of condensation is referred to as ‘the changes of the physical state of matter from the gaseous phase into liquid phase, and is the reverse of vaporization’. We may call it the dew point. Water vapour is actually all around us but is usually invisible to the human eye. Higher air temperatures will hold more water vapour, but it is when the air carrying the vapour comes into contact with a cool surface and the reduced temperature will not allow the air to hold onto the vapour.

That bit of science is the reason why millions of homes in the UK are affected by this condition, and it is a particular problem in homes that are poorly heated and insulated. If left unchecked, condensation can lead to staining and mould growth, which in turn can damage wallpaper, wall surfaces, window frames, furniture and clothing. And another more serious implication of condensation is the increased risk of illnesses such as asthma and bronchitis, caused by the tiny spores produced by the mould. Condensation can cause immense damage if left un-checked.  It can cause rot in the timbers of a property, particularly windows, where large amounts of moisture can collect. If it is allowed to soak into walls over a period of time, it will damage plasterwork and possibly even the internal block / brickwork.

Checking for condensation is important as the longer you leave it the worse it will get

Checking for condensation is important as the longer you leave it the worse it will get

Areas in the home that are most at risk would be those where a large amount of moisture is produced, such as a bathroom or kitchen, or in the vicinity of windows where the droplets run off the glass. Walls can also be susceptible if they are not insulated and the room is poorly heated.

Many homes are constructed with full depth Concrete lintels supporting the window openings. These areas can result in a section of the wall having a lower temperature.

Any airborne moisture is attracted to the colder parts typical place for mould growth is above the window. (See related images) Other prominent areas for attracting condensation are external corners and window reveals.

There are things that can be done to help reduce the moisture and so the condensation, but this often involves a change in behaviour by members of the household.

An Adult can sweat up to a maximum of amount of 10-14 litres per day. That’s over a Builders bucket of Sweat. This is a maximum however so you could recon on a family of 4 producing on average this kind of amount. This is without the water vapour produced by Cooking, Washing, Bathing & Boiling the kettle. All this water vapour has to go somewhere;

Condensation on a wall

Condensation on a wall

Air at 30 deg will hold approx. 30 grams of water per Sq m of air.- So a typical 5m x 5m room will have nearly 2000 grams equivalent to  4 ½ pounds or ¼ of a builders bucket.

Any water vapour the air can’t hold has to go elsewhere- where does it go to – the coldest thing it can find.

Water is trapped in the air as vapour, by nature it’s always trying its damnedest to turn back to a liquid. As soon as the temperature drops the Air starts to shed the vapour & it turns back to water.


Use extraction when cooking ideally all extracted air should be externally ducted

·       Tumble dryers should always be vented to the outside. Unless you have a modern condensing drier. Check the vent pipe is not damaged or kinked. Drying clothes produces a huge amount of water vapour.  Un-vented tumble driers have potential to cause a massive problem.

  • Dry washing outside where possible
  • Avoid using paraffin or gas bottles for heating
  • Close doors and open windows in rooms where steam is produced
  • Pull furniture away from walls that may be damp to allow air to circulate
  • Have extraction fans fitted to bathrooms/ wet rooms/ utility rooms

When a problem occurs it is always a good idea to check for other causes of damp and eliminate these.

  • Check accessible plumbing for leaks
  • Guttering or downpipes may have cracks or blockages
  • Check the overflow and sink waste pipes for leaks
  • Have the roof examined for possible leaks
  • How sound are the outside walls?
  • Are the levels of garden or paths higher than the damp course?
There are plenty of ways you can reduce the chance of condensation

There are plenty of ways you can reduce the chance of condensation


Increasing ventilation is absolutely essential to allow moist air to escape. This can be done by adding trickle vents and extractor fans where needed, or at the very least opening windows. Mechanical ventilation is obviously the most effective as this will physically draw the moist air out of the room without introducing colder air, and they are even better if fitted with a humidistat control.


Keeping room temperatures above 15 C will reduce condensation problems. If possible, it is a good idea during cold spells to keep a low-level background temperature going that will ensure there are no rapid changes to the environment in the property that will trigger condensation.


Increasing insulation in the roof & having cavity walls filled will help to prevent cold spots. Fitting quality Double Glazing will eliminate moisture on windows. These measures will also help to reduce heating bills.

Air conditioning units

Fitting an air-conditioning unit that has a heating ability can also help- decent quality units have the ability to extract excess water vapour and discharge it externally.

Condensation ruining wallpaper

Condensation ruining wallpaper


In extreme cases it may be necessary to use a dehumidifier. These work to extract the moisture from the air and can be bought or hired. They come in various sizes so it is important to get one that fits your requirements. The water that is collected will also need to be emptied periodically. Larger units will discharge automatically via a hose directly into a sink or bath.

As a result of modern lifestyles condensation will never be eliminated from homes completely, but there is a great deal that can be done to keep the problem to a minimum; and when you have finished reading this article and you go and make yourself a cup of tea, just watch where that moisture goes when you boil the kettle.


If you have tried all the above and are still suffering from condensation problems. Move somewhere that has a year round warm climate, where you can keep all the windows open all year round. Expect though to be challenged by other problems like flies, bugs & overzealous, Jobs -worth public officials who increasingly you will find wherever you go. All to be covered in future Articles.