Condensation, Mould and Damp

  Condensation on a window








Mould is a fungus that develops from airborne spores. It doesn’t always grow in the room where the moisture comes from and can often be found on and around windows on cold mornings, especially between October and April. It can also appear on walls and behind cupboards and wardrobes. If you spot mould in your home, wash it off and treat it with diluted bleach or a fungicidal wash (available from most DIY and hardware stores).


If you’re using a fungicidal cleaning solution to tackle small areas of mould, pay close attention to the manufacturer’s health and safety instructions; wear protective eyewear, gloves and a face mask; and make sure you open windows or use a fan in the room where you’re working

First things first...

What exactly is condensation?

It’s the name of the process whereby air that’s laden with moisture changes from a vapour into a liquid.

What causes condensation?

Condensation happens when warm, humid air (the steam from your kettle or shower, for example) comes into contact with a cooler surface (like a window or exterior wall).

The three main culprits in the home are too much moisture, not enough ventilation and inadequate heating.

So where does the moisture actually come from in the first place?

You won’t be at all surprised to discover that cooking, washing and drying clothes indoors can all add significant levels of moisture to the air. But what you may not know is that many other everyday activities add moisture too, such as using portable gas and paraffin heaters, and topping up fish tanks.

And where does the moisture end up?

Condensation can appear on and next to windows, in the corners and edges of rooms, and behind and inside wardrobes and cupboards – especially if they are against an external wall.

Why is condensation bad news at home?

You need to control and reduce condensation in your home because if you don’t, it can damage your belongings, floor coverings and walls.

How much moisture are we talking about during a typical day?

Believe it or not, in an average two-person home, the amount of moisture produced each day amounts to a whopping 24 pints!

Combating condensation – A three-pronged approach

1. Reduce moisture levels


  • Close your kitchen door, put the extractor fan on and open a window if you can – that way, the moisture you’re creating won’t be able to move to other parts of your home
  • Always put lids on boiling pans and use the extractor fan if you have one

Baths and showers:

  • Close your bathroom door and open a window (or put the extractor fan on), to prevent the moisture from moving to other parts of your home
  • If you run a bath, reduce steam levels by adding the cold water first


  • Dry clothes outside – if this isn’t possible, dry them in the bathroom with the door closed and the window open (or extractor fan on)
  • Check that your tumble drier is properly vented to the outside


  • Fit a lid on top of your fish tank


2 Increase ventilation

Picture showing open window •  Open a window – near the source of the moisture if possible

 •  Keep trickle vents open as much as possible

 •  Move furniture away from the walls slightly, to allow air to circulate behind them

 •  Check that the airbricks and vents in your walls are kept clear


3 Raise the temperature

Image showing temperature controls •  Try to heat your whole home, not just one room

 •  When it’s cold outside, leave the central heating on low all the time. This is because:

 –  Raising the temperature of the walls reduces the risk of condensation forming

 –  If room temperatures fluctuate repeatedly, you may end up with a mould problem


If you follow the three-pronged approach outlined above, you should be able to put a stop to problematic condensation in your home.

But if you’ve already got patches of black mould in your property, following our top tips alone won’t get rid of them – you’ll need to take further action.


Not all dampness in the home is caused by condensation. Sometimes it occurs because of:

  • Leaking pipes (internal or external)
  • Leaks in the roof – perhaps you have broken, missing or faulty tiles, guttering or chimney flashings?
  • Rising damp, resulting from defects in your damp proof course, rendering or mortar joints, or from blocked cavities. These types of damp problem can occur at any time of the year and often leave a tell-tale ‘tide mark’.


If you’re concerned about condensation, mould or dampness in your home or require further information, call our Resident Services team for advice on 01462 683307.