What does it mean?
A damp proof course is a barrier incorporated into a building detail to limit moisture movement through a construction element. It is commonly associated with masonry but must be understood as part of the specified moisture-control system. Position, continuity, interfaces and material suitability matter. A linear measurement alone does not establish whether a proposed detail will perform correctly.
In practice
A straight 10 m wall may need 10 m of net DPC along one course, with separate allowances for laps, junctions and returns. Width must suit the specified wall detail and product.
Keep in mind
When preparing an estimate, record the specification reference, units and source of each assumption. Separate the net measured quantity from purchase allowances so changes remain easy to trace. Confirm product dimensions, yields and installation requirements with the supplier. Quantities do not establish structural adequacy or material suitability: use the project’s approved design and details, and seek the responsible designer’s clarification where the specification is incomplete.