Most homes experience damp at some point. Damp can lead to mould growth on walls, windows, furniture and personal belongings. It can make your home uncomfortable and, if left untreated, may damage your home and pose a serious risk to your health.
Identifying the type of damp can help you understand what is causing it and what action to take.
There are 3 common types of damp found in residential properties. Each type has different causes and signs to look out for.
Condensation
Condensation is the most common type of damp. It happens when there is too much moisture in the air and that moisture settles on cold surfaces.
It is more common during cold weather and is the most common cause of black mould in homes.
You may notice:
- water droplets on windows and other cold surfaces
- black mould around windows, walls or ceilings
- damp patches that appear in corners or behind furniture
- mouldy smells
Rising damp
Rising damp happens when water from the ground moves up through walls and into your home. It is usually caused by a damaged damp proof course or where there is no damp proof course at all.
Rising damp only affects basements and ground-floor rooms.
You may notice:
- a tide mark on walls, usually less than 1 metre above the floor
- peeling wallpaper or paint near floor level
- damaged plaster
- white salt deposits on walls
Mould is rarely seen with rising damp and usually only appears in the early stages of the problem.
Penetrating damp
Penetrating damp occurs when water enters your home through external walls, roofs or internal leaks.
This may be caused by:
- missing or damaged roof tiles or slates
- blocked or overflowing gutters
- leaks around window frames
- leaks from water or waste pipes inside the home
You may notice:
- damp patches on walls or ceilings that become worse after rainfall
- walls that feel wet to the touch
- damp areas near plumbing or water pipes
Mould is rarely seen on areas affected by penetrating damp.
