Introduction
Rising damp is one of the most common moisture problems in buildings, especially in older houses. It occurs when water from the ground moves upward through the walls by capillary action. This process is slow but progressive, and if unnoticed, it can affect the comfort and appearance of a home. Understanding what rising damp is and how to recognise it helps distinguish it from other types of damp.
How does rising damp occur?
- Capillary effect: water from the ground is drawn upward through the pores of building materials.
- Absence of a barrier: many old buildings lack a proper horizontal damp-proof course, or the original one has deteriorated.
- Ground contact: walls in direct contact with soil are the most exposed to rising moisture.
Typical signs of rising damp
1. Stains on the lower parts of walls
Dark or irregular marks usually appear up to about one metre above floor level.
2. Efflorescence (white salt deposits)
When water evaporates, it leaves behind salts that form white, powdery patches on the surface.
3. Flaking paint or plaster
Finishes may detach as the moisture affects the wall from within.
4. Persistent musty smell
Even after ventilation, a damp odour can remain in affected rooms.
5. Cold wall surfaces
Walls feel colder to the touch, which can also increase the risk of condensation.
How to distinguish rising damp from other damp problems
- Condensation: caused by excess indoor humidity settling on cold surfaces (common in kitchens and bathrooms).
- Lateral penetration: caused by rainwater or leaks entering through cracks, façades or basements.
- Rising damp: located mainly at the base of walls, often accompanied by efflorescence.
Non-invasive technologies against rising damp
Alongside traditional methods such as chemical injections or physical barriers, there are modern technologies designed to act directly on rising damp:
- Electronic systems (ATE): work with electronic impulses that influence how water molecules move in the wall.
- Geomagnetic systems (ATG): use natural geomagnetic fields, functioning continuously without electricity.
These devices are installed without construction work and are considered alternative approaches to treating capillary moisture.
Conclusion
Rising damp is a form of moisture that appears mainly in the lower parts of walls. Its signs include stains, salt deposits, flaking finishes and persistent damp odours. Recognising it helps to separate it from condensation or leaks. Various solutions exist, from traditional interventions to modern systems such as ATE and ATG devices, which are specifically designed to act on capillary moisture.
