We believe that rising dampness exists, however it is not as common as is made out by many damp proofing contractors. Rising damp usually occurs in walls where the foundations extend down below the ground water table. The water rises either through the bricks or the mortar joints due to fine capillaries or pores in the materials. (A process known as 'Capillarity') There are three main factors that affect the quantity of moisture absorbed by the wall and the height to which it rises;
1. The capacity of the wall material to absorb moisture
2. How wet the ground is
3. How quickly the moisture can evaporate
Water will continue to rise up the wall until it meets a physical barrier. The construction of most modern buildings includes a damp proof course (DPC) - a layer of impermeable material (eg: slate, bitumen, plastic) built into the external walls just above ground level. The DPC prevents moisture rising up the wall construction. In the absence of a damp proof course, then water has the potential to continue to rise up the wall to heights of approximately 1.5m. Many situations where rising damp occurs is often due to the bridging of the existing damp proof course rather than the absence of one. Older building, particularly those with solid stone or brick external wall, do not always have a DPC. It is assumed that rising dampness is likely to be a problem in these types of properties, however a full investigation of the cause of dampness must be carried out to determine if rising damp is indeed the cause.