Houses are usually built with a damp proof course dpc just above floor level to prevent moisture rising up but if this has failed or the property did not have a dpc then rising damp can occur.
Damp proof course above internal floor level.
Where it is not possible to insert a damp proof course 150 mm above the external ground level for example if the building has a solid external wall and the internal floor level is less than 150 mm above the external ground level external drainage solutions may be necessary such as the installation of a french drain.
A quick summary checklist.
External ground levels ideally need to be lowered 150mm below the damp proof course or the internal flooring.
Tip 1 if a concrete floor is damp all over it is hard to isolate the moisture source.
By simply lowering external ground levels this will allow wall base evaporation to help control rising dampness.
The below diagram shows what bridging of the damp proof course looks like.
Generally damp proofing keeps moisture out of a building where vapor barriers keep interior moisture from getting into walls.
Dpc material for cavity walls.
Rising damp usually occurs in masonry walls because of the failure or absence of a damp proof course although poor sub floor ventilation and bad site drainage can also be contributors.
Depending on the extent of the rising damp this can be a more costly and extensive job to repair.
Waterproof is defined by the astm as a treatment that resists the passage of water under pressure.
Dpc material for situations where differential thermal movements occur.
Dpc above ground level.
Methods of damp proof course installation in construction.
Types of materials for damp proof course.
Dpc material for floors roofs etc.
Selection of materials for damp proof course in buildings.