Condensation and Mould Advice

Condensation is caused when warm, moist air hits a cold surface (like a window or external wall) and condenses, running down the cold surface as water droplets.  

Condensation comes from cooking, and drying clothes and even our breath. It is not caused by a fault with the building or damp from the outside.  

If it's not managed, condensation can cause black mould growth on walls, ceilings, furniture, clothing and even in or behind wardrobes and cupboards. Any damage to belongings caused by condensation is your responsibility.  

There are some steps you can take to manage condensation before it becomes a problem.  

Watch his short animation on condensation, damp and mould:

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How to manage condensation 

You can take steps to manage condensation in your home and prevent it from developing into mould, including: 

  • Ventilating your home. Fresh air clears the moisture 
  • Wiping down surfaces where moisture settles such as windows and sills every morning in cold weather 
  • Covering boiling pans when cooking and using an extractor fan 
  • Drying clothes outside where possible. If you have to dry clothes inside, try and do so in a small room with the doors closed and windows open 
  • Making sure tumble dryers are vented to the outside 
  • Switching on kitchen and bathroom fans, if these are fitted in your home. 
  • When cooking, bathing or washing, close kitchen and bathroom doors to prevent steam going into colder rooms.

Other ways to manage condensation include:

  • Increasing ventilation by opening windows and using the extractor fan, even after you have finished. 
  • Maintaining a low constant heat in your home when the weather is cold or wet. This is more effective than short bursts of high heat and needn’t mean increased heating costs. Your room heating thermostat should ideally be set between 18°C and 21°C.  

If you are worried about your heating bills, our Money Advice team can offer free confidential advice. 

Visit the Money Advice team page

What to do if you see mould developing in your home 

If condensation is not managed it can develop into mould. Mould looks like black spots or patches on surfaces, which can look and smell unpleasant.
If is spreads and is left untreated, mould can damage your belongings and can lead to health problems, particularly for young children, the elderly and people with certain health conditions.  

There are some steps you can take to clean mould off surfaces and prevent it from spreading, including:

  • Use a mild bleach solution to remove light mould staining on hard surfaces 
  • Wipe down walls and window frames with a fungicidal wash. Follow the manufacturer's instructions carefully 
  • Dry-clean mildewed clothes and shampoo carpets if they have been affected 
  • Improve ventilation to reduce moisture in the air and stop the mould reoccurring 

After treating mould, you may choose to redecorate using a good quality fungicidal paint to help prevent mould recurring. Please note, this paint is not effective if painted over with ordinary paints and wallpaper. 

If left untreated, mould can be harmful to your health. Young children, older people and those with underlying health conditions can be at risk. If you are worried about mould affecting your health, please seek help from your GP and let us know.  

How to contact us  

If you have taken all the recommended steps to reduce mould but it keeps spreading, it may be caused by a leak or structural fault in your home. If you notice a leak or damage to any part of your home (e.g cracks in window frames or gutters), please let us know as soon as possible.  
If you are concerned about mould in your home, we are here to help.  

  • Contact us via the ClanmilConnect app or online portal  
  • Phone us on 028 9087 6000 
  • Email  

How we can help  

We can arrange to visit your home and complete an inspection and measure the levels of damp in your home. We may also treat the affected areas. In addition, we will offer practical help and advice and carry out any necessary repairs to prevent the mould reappearing. 
If you are not happy with the service we have provided, you can make a complaint by emailing

Useful resources 

You can view and download this information leaflet: 

Managing Condensation and Preventing Mould