Causes of damp
It is important to find out what is causing the damp. This means the right steps can be taken to fix it. If you are a tenant you should report damp and mould to your landlord. Your landlord is responsible for looking into the problem and taking steps to prevent it. The main causes of damp and mould are listed below.
Condensation
There is always some moisture in the air even if you cannot see it. The warmer the air, the more moisture it can carry. When the air can't hold any more moisture (saturated), it forms water droplets ( condenses) when it comes into contact with cold surfaces.
Condensation occurs mainly during cold weather. This is because cold air holds less moisture before it becomes saturated and condenses. Condensation is often found on colder, external walls, on and around windows, in corners and behind furniture where there is less air flow.
Condensation is the most common cause of damp in the home. It can be cause by a number of things such as inadequate heating, ventilation or insulation; excess moisture being generated and overcrowding.
Leaks and penetrating damp
Leaks from faulty plumbing and leaking bath and window seals cause dampness in the home.
External issues can cause water to seep in through the structure. Example issues could be:
- missing tiles to the roof
- blocked or damaged guttering
- downpipes or waste pipes
- issues that cause water to flow from overflow pipes
Rising damp
This occurs where water rises up from the ground. This can be through the floor or into the walls of the building where the damp proof course is missing, has failed, or has been bridged. Bridged means water is able to bypass the damp proof course's waterproof barrier.
There is usually a tide mark on affected walls and this only occurs at up to about one metre from ground level.