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Damp and mould

Dampness is one of the major problems faced by home occupiers and can be caused by several factors such as condensation, rising dampness, penetrating dampness and leaking pipes.

Fore more information see: Health risks of damp and mould in the home.

Report a repair problem with a private landlord


During the winter months, many properties suffer from damp and mould growth due to condensation.

Causes and signs of condensation

Air can hold moisture, the warmer the air, the more moisture it can hold. If moist air is cooled by contact with cold surfaces, such as walls, windows or mirrors, the moisture condenses into water droplets (condensation).

Mould often occurs because of condensation. It appears as pinpoint black spots, usually on the side surfaces of external walls, in corners and in poorly ventilated spaces, such as behind cupboards and wardrobes.

Principles of condensation control

This needs a combination of sufficient heating, ventilation and insulation:

  • Sufficient heating + adequate ventilation + insulation = less condensation.


By introducing low level heating, the temperature of internal surfaces will rise. This will reduce cooling of any moisture-laden air and, consequently, the amount of condensation. Ideally, low level background heating should be continuous, as any short bursts of heat may not result in a suitable rise in surface temperatures.


Thermal insulation, such as loft or cavity wall insulation, draught proofing and double glazing, will help to reduce the amount of heat lost from a property. This will not only help keep internal room temperatures higher, but will also help keep fuel bills down.


Adequate ventilation is essential to allow moisture-laden air to escape from the home before condensation occurs. Mechanical extract ventilation systems in the kitchen and bathroom can prove very effective in reducing condensation, especially when fitted with an effective humidistat control.

Extreme cases

  • A dehumidifier, which extracts moisture from the air, can be bought or hired.
  • Wipe down surfaces affected by condensation regularly, to prevent mould growth.
  • Mould can be removed by washing the surface with a disinfectant or a fungicidal wash. This must be used in accordance with the manufacturers' instructions.
  • Mould-inhibiting paints and sprays can also help to reduce the effects of condensation.

How to reduce condensation

  • Pull wardrobes and furniture away from walls and keep tops of wardrobes clear to allow air to circulate.
  • Close doors and open windows when cooking.
  • Keep lids on saucepans when cooking.
  • Keep bathroom doors closed when bathing and open windows slightly afterwards.
  • Do not dry clothes on radiators, unless ventilation is increased.
  • Only use Liquid Petroleum Gas or paraffin heaters in ventilated rooms, as these fuels produce water vapour during combustion.

Rising damp

Rising damp normally occurs in properties which either have not been built with a damp proof course (DPC) or where the DPC has failed. The most obvious signs of rising damp are a brown "tidemark" on the wall and the plaster below feeling cold or damp to the touch. Rising damp can affect any wall in contact with the ground and therefore can affect internal as well as external walls. It does not normally rise above about a metre in height.

Penetrating damp

Penetrating damp can affect almost any location in the home and is usually the result of a building or plumbing fault allowing water to enter into the property. Building faults commonly encountered giving rise to penetration dampness are leaking flashings to the chimney, leaking roofs or back to earth properties with no vertical damp proof course.

A brown stain normally occurs on the affected surface, which grows in size as more water penetrates. If the fault is not rectified, plaster will start to perish and in the case of ceilings, could even collapse. If you think you have a problem with penetrating damp, you should have the fault repaired as soon as possible.

Traumatic damp

Traumatic damp can be caused by leaking water from waste and heating pipes, overflowing baths or sinks, burst pipes or defective water storage vessels inside the building. Traumatic damp can also originate from outside the property, for example from another building or from environmental flooding.

What you can do

  • If the damp problem is as a result of condensation follow the advice above.
  • If the damp problem is as a result of penetrating or rising dampness and you are a tenant then your landlord is responsible for resolving the problem. You should contact your landlord to inform them of the problem and agree when the work can be carried out. You should always give them the opportunity to resolve the problem before contacting us.
  • Are you an owner occupier and need a contractor? It is advisable to contact someone registered with a recognised trade body or contact TrustMark.
  • Do you suspect your home is affected by rising damp? You should have the property surveyed by a contractor who is either registered with the TrustMark scheme or a member of the British Timber Treatment and Damp Proofing Association, whose members are usually listed in Yellow Pages.

What we can do

If your landlord will not do essential repair works, we may be able to help you, contact:

Community Safety: