Damp Proof Course Installations in Telford, Shrewsbury, Wolverhampton and Surrounding Areas of the West Midlands

A damp proof course (often abbreviated to DPC) is a horizontal barrier in a wall designed to prevent moisture rising through the structure by capillary action - a phenomenon known as rising damp.

Building standards in many countries require most new buildings to incorporate a DPC at the time of construction. This may consist of a thin strip of plastic, a course of engineering brick or slate, or a layer of bitumen.

Where a DPC is absent or inadequate, there are various means of retrospectively fitting one. A common method in masonry walls is to drill holes into the wall at regular intervals and inject a penetrating chemical (e.g. silicone) into the holes. The chemical is absorbed into the masonry where it dries to form a waterproof barrier. Some irregular stone walls cannot be drilled for a chemical DPC, so an osmotic electrical system is often fitted.

Alternatively the cement joints can be drilled and the chemical injected there instead, although this is a less satisfactory method. A larger volume of chemical will be needed.

Some forms of the chemical are odour free, some have a strong odour, this should be taken into account when purchasing.

A Damp Proof Membrane (DPM) performs a similar function for a solid floor.