Damp and condensation

What is condensation?

There is always some moisture in the air, even if you cannot see it. You notice it when you see your breath on a cold day, or when the mirror mists over when you have a shower or bath.

Condensation is caused when moist warm air meets a cold surface like a window or wall and condenses into water droplets. If this happens regularly, mould may start to grow and leave a musty smell. This usually appears on cold outside walls and surfaces and in places where the air does not circulate well. The moisture created can also damage clothes, furnishings and decoration.

Condensation can aggravate health problems like asthma, bronchitis, arthritis and rheumatism.

What causes condensation?

Condensation usually occurs in winter because the building is cold and windows are opened less so moist air cannot escape.

Is your dampness caused by condensation?

If it has ‘tidemark’ effect it is damp, not condensation. It could be caused by rain seeping through windows, or rising dampness due to a defective or missing damp proof course. Please contact us so we can investigate the problem.

There are three main ways to tackle the problem

  1. Stop moisture building up
  2. Ventilate or air the home
  3. Keep your home warm

The difference between damp and condensation

Damp occurs when a fault in the building’s basic structure lets in water from outside. There are two types of damp, penetrating damp and rising damp.

Penetrating damp occurs when water is coming in through the walls or roof, (for example, under a loose roof tile, leaking pipes or waste overflow) or through cracks.

Rising damp is rare but if this occurs there is a problem with the damp proof course. This is a barrier built into floors and walls to stop moisture rising through the house from the ground. The usual evidence of rising damp is a ‘tide mark’ on the walls that shows how high it has risen. There is also a musty smell.

If your home suffers from any of these damp problems, please contact us on 020 8726 6101.

For more information on how you can combat condensation, please download our booklet ‘


Repairs - council homes

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Floor 2, Zone D, Bernard Weatherill House
8 Mint Walk
Croydon CR0 1EA
United Kingdom