Tackling damp, condensation and mould

Last updated - 6 February 2018

Damp in your home can cause mould to grow, ruining your clothes, furniture and decorations.

Damp can be caused by:

  • Rising Damp - Faulty damp proof course
  • Water Penetration - broken guttering, missing roof tiles, defective windows etc
  • Condensation – this is the main cause of damp and is caused by a lack of air movement within a property.
    Condensation occurs when warm, moist air comes into contact with a cold surface like a window or outside wall, turning it into water. Signs of condensation will often be found on:
  1. External walls that get little sunlight making them cold
  2. In the outer corners of walls
  3. Near cold pipes
  4. Toilet cisterns
  5. Cupboards
  6. Behind wardrobes and beds
  7. Areas of the home which have little or no air movement.

Throughout every day we all put moisture into the atmosphere within our homes. Cooking, bathing, showering, making hot drinks and even breathing all contribute to this.

Below you can see how much extra water you add to the air inside your home on a daily basis:

  • Two people at home - 2 pints
  • One bath or shower - 2 pints
  • Drying clothes indoors - 9 pints
  • Cooking or using the kettle - 6 pints
  • Washing dishes -  2 pints
    Other causes of damp include leaking appliances such as faulty pipes.
    Covering cooking pans when cooking can help to reduce the amount of water vapour released in to your kitchen.


Keeping the home warm and well ventilated is a must in the battle against condensation and mould growth. Windows should be left open for a little while each day to allow fresh air to circulate. Mould does not like fresh air as it dries surfaces that mould likes to cling to.

This video provides some helpful advice on avoiding and treating mould and condensation:

Mould should be cleaned off walls on a regular basis using a suitable cleaner (when it is only a small area). It will grow back but you will have to persist in cleaning it off every time it reappears.

Wipe down any wet surfaces; especially around and on windows, the more you remove from the home the better. Condensation likes cold surfaces like external walls around window reveals and solid concrete ceilings.


If you don't clean mould off and manage the condensation it will grow to cover all cold surfaces within the home. Over time the mould will colour the surfaces black while giving off a musty unpleasant smell.

Many homes have been improved by the fitting of UPVC (plastic) double glazed windows. These windows provide us with draught proof and secure windows. Leaving the small trickle vent open is good practice in helping with the management of condensation within the home.

There is no cure for condensation, however the following tips can assist with the management of condensation and the mould that comes with it:

  • Keep window trickle vents open.
  • If drying clothes indoors ensure you open a window to help ventilate it.
  • If using a tumble dryer ensure you open a window to ventilate.
  • When cooking use an extractor fan or opening a window; you should also cover any saucepans with lids.
  • When bathing or showering keep the bathroom door closed and ensure the extractor fan is on or open the window.
  • Try not to overfill cupboards or wardrobes, allowing air to circulate around items.  This prevents moisture building up.
  • Allow adequate air circulation around furniture – don’t push sofas and wardrobes right up against walls.

The key to controlling condensation is ventilation. Opening a window and keeping the property at an even temperature and clutter free will help prevent extensive growth. Condensation and moisture traps are available from large DIY stores and will help you control the situation.


Tips to avoid condensation

You can control condensation by following these basic steps:

Drying clothes

When drying clothes indoors, you should open windows.  This increases air circulation.  If you use a tumble dryer that has no vent to the outside, then additional ventilation is essential.


Keep kitchen, utility room and bathroom doors shut when in use and make sure there is plenty of ventilation.  Otherwise moist air will spread throughout your home.

Extractor Fans

If you have extractor fans fitted use it as soon as you start cooking, washing clothes or bathing.  You should also use it when windows start to get steamed up.

Kettles and Pans

Don’t boil kettles and pans for longer than necessary.

Cupboards and Wardrobes

Try not to overfill cupboards and wardrobes.  Try to allow space between stored items and at the back of shelves for air to flow.  A good way to avoid mould is to fit ventilators to wardrobe doors.  Allow air circulation space at the back of free-standing wardrobes.

Mould Growth

Mould growth usually appears because of condensation and lack of ventilation.  It can be cleaned off the affected areas with a fungicidal solution which can be bought at local DIY stores.  You can also get special paints that help to prevent mould from coming back. 


You are responsible for insuring the contents of your home.  House contents insurance covers you against loss or damage to furniture, household goods, clothing and personal items from a variety of risks. These can include fire, theft and water damage.

Why do I get condensation?

Warm air can hold more water vapour than cold air.  When moist, warm air meets a colder surface (eg a window, mirror or wall) the water vapour cools.  It then appears as drops of water.  This is condensation.

So the warmer you keep your home, the less likely you are to get condensation.

When does condensation become a problem?

All homes suffer condensation at sometime.  This is usually when large amounts of steam and moisture are being produced.  This can happen when you prepare a meal, when you have a bath or shower, or when you wash and dry your clothes.

It is quite normal to find windows misted over in the mornings.  This often happens after a cold night.  However, if your home always has condensation, the following advice will help.

How do I know if I have condensation?

Other kinds of dampness are often confused with condensation.  Rain penetration, leaks from your plumbing system and central heating, or rising damp which often leaves a stained line.

Condensation will often be found in the following places:

  • on walls that are in the shade
  • on walls that face North
  • in the outer corners of rooms
  • in unventilated cupboards
  • under worktops
  • near cold water pipes
  • and in places where there is little or no air movement.

It is worth checking all pipes for leaks.  Check under the sink.  Check overflows from cisterns and tanks.  Check behind the w.c. and radiator connections.  Have a good look outside for missing roof tiles, leaking gutter joints and loose fitted rainwater down pipes.

What can I do about condensation?

You can reduce condensation by keeping your home warm.  In the coldest weather do not let the temperature of the home drop away.  Maintain a background heat.  Once dwellings get very cold, they can take a long time to warm up.  This can be costly.

The following tips can help keep costs down:

  • Ensure that your heating system or appliances are regularly checked, and serviced.  This ensures that they are working efficiently
  • If you struggle to afford adequate heating, your fuel supplier, gas supplier or electricity supplier may be able to help.  They can provide saving stamps or tokens, or budget schemes.  These can help spread the cost of fuel
  • Ensure you are getting any assistance or benefits that may be due to you.  Your housing department will be pleased to advise.
Does ventilation help stop condensation?

You need adequate ventilation in your home to stop condensation from forming.  Draughts are unwelcome, but some ventilation is essential.  Try to remember the following:

  • Even in winter, when the glass is misted over, open the window a little until it is cleared.  Don’t let it build up
  • Try to ensure that draught stripping to doors and windows allows a small amount of air to get through.
  • Make sure window ventilators are opened when you are asleep at night
  • Ventilate kitchens and bathrooms when in use
  • If you are removing a fireplace do not block off the flue.  Allow some ventilation by fitting an air vent (don’t forget, you will need permission from the Council for this)
  • Do not use paraffin or bottled gas heaters in unventilated rooms.  You will need to provide extra ventilation if you use one. These flue-less heaters can produce equal amounts of water to fuel used and also produce carbon monoxide which is extremely dangerous.