Interior view of a bare roof suffering from damp.
Damp ingress results in organic growth and damage to plaster. © Historic England
Damp ingress results in organic growth and damage to plaster. © Historic England

Investigation of Moisture and its Effects on Traditional Buildings

Moisture is present in all buildings. It is in the materials they are made from and in the environment that surrounds them. This moisture, however, does not necessarily make a building damp. Nor is it always damaging. Moisture in buildings is only a problem when there is too much of it.

Excess moisture accumulates in building fabric for many reasons. Occupants’ activities, building defects, faulty engineering services, and leaking utilities and drains are all common sources of moisture. Groundwater and emergencies, such as flood and fire, may also play a role. Determining the causes of damp may not be easy. Time and money can be wasted if the cause of damp is not properly diagnosed. In such cases, far from solving the problem, remedial work can make it much worse.

Historic England welcomed the opportunity to work with the Royal Institution of Chartered Surveyors and the Property Care Association to develop and publish this set of competencies and principles to underpin investigation and treatment of damp in traditional buildings. The document explains the issues that surveyors and contractors should take into account and provides a best-practice framework for each stage of the diagnostic investigation and repair process.

Crucially, the approach described is based on understanding old buildings and how moisture moves within them. It should help to ensure that remedial work treats the cause of the problem, rather than just tackling symptoms. This will benefit the buildings and their owners, as well as the wider environment.