What is a damp proof course, and what does it do?
A damp proof course (or DPC) is a layer of material between the foundation and the rest of the building which prevents water from getting into the building fabric. In a new building it is standard and cheap to fit a DPC during construction. Traditionally these were two overlapped layers of slate or lead, though some old buildings do not have them at all. Modern buildings tend to use bitumen or polythene based materials (you can get recycled plastic DPC). Land drainage around a building is also important. Do I need a new one? Timber frame buildings with minimal foundations will only need small amounts of DPC material. It is important to fit a DPC here as timber can soak up moisture (this being how trees live!) and will rot if not able to dry out easily. However whether masonry or brick buildings do the same is open to debate. There is a growing school of thought that ‘rising damp’ is an urban myth (or a complete con) and that retrofitting chemical DPC’s can be a waste of money, quite ap
