Damp, mould and condensation

Types of damp

Rising damp

Water penetrating from ground level up into the home. The water can penetrate a defective damp proof course or brick work, affecting the ground floor and/or basement. It will often leave a ‘tide mark’ up to around one metre from ground level. If left untreated, plaster can become saturated and crumbly and can lead to dry or wet rot to timber and masonry.

Penetrating damp

An external source of water that penetrates through external walls or the roof and ceiling and is usually accompanied by damp patches. It can be caused by issues such as missing pointing, cracked rendering or missing roof tiles.

Defective plumbing

Damp can be caused by defects to the plumbing - both water supply and waste pipes or the facilities - and is usually accompanied by a leak or damp patches on walls or ceilings.

Mould will usually not be present, but the issue will require investigation and remedy as soon as possible.


The most common type of damp - it is a combination of moisture production inside the home coupled with heating and ventilation. Condensation can cause black mould growth.

Moisture is produced through every day activities:

Amounts of condensation produced from a variety of household activities
Activity  Amount of condensation produced 
Two people at home for 16 hours
Three pints
A bath or shower
Two pints
Drying clothes indoors
Nine pints
Cooking and use of a kettle
Six pints
Washing dishes
Two pints
Bottled gas heater (eight hours' use) 
Four pints

The amount of condensation in a property will be affected by:

  • The amount of moisture produced by the occupant
  • The temperature of the property 
  • The amount of ventilation/air circulation to the property.

All of these factors will need to be considered to reduce issues relating to condensation.

How can I prevent issues of damp and mould in my home?

Less moisture

Dry clothes outside if possible or dry those in a bathroom with the door closed using either an open window or extractor fan to ventilate. Wipe down any condensation as and when it is produced such as on windows and bathrooms walls. If a tumble dryer is used ensure it is vented to the outside. Keep doors closed when carrying out moisture-producing activities.


Ensure that the heating is adequately used to heat the home - on cold days, try to keep temperatures at 18 degrees centigrade as a minimum.


Ensure adequate ventilation, particularly during and after moisture-producing activities. Ensure extractor fans are working.  Do not block up air vents, chimneys or flues. Leave space between the back of furniture. On dry days, open windows for ventilation.

Further information

What should I do if there is damp and mould in my home?

If there is an issue with damp and/or mould in the home it is important that it is reported to your landlord as soon as possible.

If you require more information on damp and mould or need to report damp and mould in your home - please call the Private Sector Housing Team on 01442 228574 or email pshousing@dacorum.gov.uk.

If you are a council tenant, you can report damp and mould online.

Page Last Updated: Tuesday, 28 November 2023 at 11:58 AM

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