Damp, mould and condensation


Damp occurs in moist places that never fully dry out, usually where there is little air movement. Damp usually creates a ‘tide mark’ if it has come from outside sources and you may notice a damp smell. The main causes of damp in the home are:

  • leaking pipes, wastes, drainage, and overflows
  • rainwater from defective roof coverings, blocked or leaking gutters and broken pipes
  • penetrating dampness around windows, through walls and due to raised ground levels
  • rising damp due to lack of, or no effective, damp proof course

If the damp in your home doesn’t come from an outside source, then it is probably due to condensation.


There is always some moisture in the air, even if you cannot see it. If the air gets colder, it cannot hold all the moisture and tiny drops of water appear. This is condensation. You also notice it when you see your breath on a cold day, or when the mirror mists over when you have a bath or shower. Condensation can often develop in kitchens and bathrooms. Moisture is released into the air through normal daily activities in these areas such as washing, cooking, drying clothes, showering, and bathing. Condensation can occur commonly on windows or external walls, or cold surfaces within the fabric of the property. Look for it in corners, on or near windows, in or behind wardrobes and cupboards. It often forms on north-facing walls.

We can produce a lot of water just from daily activities:

How much moisture we produce from daily activities

Type of daily activity

Amount of moisture produced in pints

Two active people (1 day)


Cooking / electric kettle


Bathing / showering


Washing clothes


Drying clothes indoors


Total moisture in just one day

21 pints

Damp and condensation problems in the home

Damp and condensation can lead to staining and mould growth, which can damage wallpaper, wall surfaces, window frames, furniture, and clothing. The development of mould growth is the most tell-tale sign that is frequently associated with condensation. The appearance of mould may be black, white, yellow, or green in colour, depending on the specific type of mould and the surface that it grows on.

How to prevent condensation and minimise the amount of moisture

These simple steps will help you produce less moisture in your home:

  • using pan lids when cooking
  • ventilating bathrooms, kitchens and living areas when in use by opening windows and always having trickle vents open
  • closing kitchen and bathroom doors when in use to help prevent moisture reaching other rooms, especially bedrooms which are often colder
  • make sure your extractor fan is working and you use it whenever you are running a hot bath or cooking in the kitchen and leave it running for at least 20 minutes after showering/bathing and wipe down wet surfaces in the bathroom such as tiles, toilet cistern and shower screens
  • drying washing outside where possible rather than on radiators. If you have wet clothing in the home ventilate the room by opening windows
  • if you have a tumble dryer, make sure it’s properly ventilated
  • keeping a small window ajar when anyone is in the room for any length of time
  • try to keep the temperature in your home constant
  • wipe down any condensation you find in the morning from windows or this will just evaporate and go somewhere more damaging

It is recommended that all rooms be maintained at not less than 10°C  in order to reduce condensation. When living rooms are in use their temperature should be raised to about 20°C 

If rising energy costs mean you are struggling to pay for heating, please visit our cost-of-living pages for more advice.

How to remove mould

  • wipe mould off immediately with water using a sponge or cloth
  • do not use washing up liquid or bleach
  •  you use anti mould removal liquid to remove mould, available from most high street stores (read all instructions carefully before use)
  • do not simply paint over mould. Properly clean/remove it first then use a special fungicidal paint to help prevent it recurring


Black mould in the corner of a windowsill

Black mould caused by condensation on windows.

Black mould on the ceiling of a bathroom

Black mould in the bathroom caused by condensation. 

Damp marks on the skirting board by the floor

Rising damp (above and below)

Damp on the wall


Our handling procedure

Damp or mould should be reported to Housing Repairs by a resident. We will then gather more information and share guidance on preventing damp/mould and request photos.

Housing Repairs will send a letter out to the resident with mould information, if required and the property is added to our internal tracker and an order raised for a damp inspection. A surveyor from a specialist company will then call the resident, have a chat to get a better idea of the issues/causes and book an inspection.

During the inspection damp readings will be taken, ventilation will be reviewed and the surveyor will summarise the potential causes and the remedies in a report. If no repairs are identified, then the surveyor will talk through with the resident the causes and effects and give advice.

If repairs are required, orders will be raised.

Contact us now

If you suspect that you have damp, mould or condensation within your home then please contact our repairs team so we can arrange for an inspection to investigate further.
Call us on 01903 737827
E-mail us at housing.repairs@arun.gov.uk