Rising dampness is defined as the vertical transmission of water from the ground, up through a permeable wall structure. The water rises up through the wall structure under capillary action, i.e. the wall acting like a wick. Rising dampness can occur in a property where either there is no damp proof course insitu, or where the existing damp proof course has become ineffective due to the breakdown of the material used, or by bridging.  Dampness may also rise up walls under capillary action due to leaks or other internal/external defects causing excessive dampness on wallbase areas.

 

Bridging of the damp proof course (if one exists) may be caused by many defects, including raised ground levels, high path levels, blocked wall cavities and incorrect re-plastering.  These same defects/factors can also be responsible for the lateral penetration of moisture into lower sections of walling, irrelevant of whether a damp-proof course exists or not.

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Suspended timber floors, joist ends and other timbers, which are adjacent to or imbedded into walls subject to rising dampness, are particularly susceptible to Wet Rot and Dry Rot attack.

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Within a property, rising dampness/defects often result in the breakdown and spoiling of the plaster and decoration.  It can also considerably deteriorate concealed brickwork and masonry, and is very often the main cause of fungal decay to ground floor timbers.