Dunction and position of dpcs

The function of a damp-proof course is to provide a barrier to the passage of moisture from an external source into fabric of the building , or from one part of the structure to another.

Damp-proof courses may be either horizontal or vertical , and can generally be divided into three types:

• Those below ground level to prevent the entry of moisture from the soil
• Those placed just above ground level to prevent moisture creeping up the wall by capillary action
• THose placed at openings , parapets and similar locations to exclude the entry of the rainwater that falls directly onto the fabric of the structure
• There should be a continuous horizontal dpc above ground in walls , to prevent moisture from the ground rising through the foundation to the wall above ground , which otherwise would make wall surfaces damp and damage wall finishes .
• THe dpc should be continuous for the whole length and thickness of the wall and be at least 150mm above finishes ground level to avoid the possibility of a build up of material against the wall acting as a bridge from moisture from the ground

moisture rises through material to wall above , DPC too close to ground

• A DPC in external walls should unite with the dpm in , on or under the concrete bed , by the same level as the dpc in the wall or by uniting dpm and dpc laid at different levels with a vertical dpc