Damps

Damps is a term used to describe the presence of moisture in air or on surfaces. Dampness can range from a light, barely perceptible moisture to damp patches and persistent wetness. In buildings, dampness is a common problem that arises when humidity exceeds the environment’s capacity to dry.

Types of damp in construction include rising damp, penetrating damp, and condensation damp. Rising damp occurs when groundwater moisture travels upward through porous walls, typically managed with a damp-proof course and proper drainage. Penetrating damp happens when water enters through cracks, leaks, or faulty coatings. Condensation damp results from indoor humidity meeting cold surfaces, causing moisture to condense on walls and windows.

Causes and consequences of damp include poor ventilation, inadequate insulation, leaks, heavy rainfall, and high indoor humidity. Damp can damage building materials, promote mold growth, and cause health concerns such as respiratory irritation and allergic reactions. It can also lead to paint failure, wood rot, and structural deterioration if left untreated.

Detection and mitigation involve monitoring relative humidity with hygrometers and aiming for about 40–60% relative humidity indoors. Mitigation techniques include improving ventilation, increasing heating and insulation, dehumidification, sealing leaks, repairing damaged masonry, and installing damp-proofing measures. Regular maintenance and moisture control help prevent damp problems from worsening.

See also: humidity, mold, damp-proofing, building moisture management.