Coping

A coping is the capping or covering laid along the top of a wall, including the parapets of low-slope roofs. Its job is to shed water off the top of the wall and away from its faces, and on a roof it also covers and protects the top edge of the membrane where it runs up and over the parapet. The word derives from "cope", from Latin capa, a cloak.

Materials

• natural and cast stone, precast concrete, brick and terracotta
• sheet metal: aluminium, galvanised or coated steel, stainless steel, copper and zinc
• tile, slate and other units on traditional walls

Metal copings are the most common choice on commercial low-slope roofs because they are light, quick to install and available in long lengths with concealed splice plates at joints.

Design features

• Weathered top: the top surface is sloped or curved so water runs off, usually toward the roof side so dirty water does not streak the façade.
• Drip: in UK practice a coping projects beyond the wall face with a drip or throating so water falls clear; a flush capping without a drip is distinguished as a "capping".
• Joints: masonry copings need sealed or flashed joints; metal copings use cleats, splice plates and allowance for thermal movement.
• Underlay: a waterproofing membrane under the coping protects the wall top if joints leak.

Wind resistance

Edge metal and copings are a common point of failure in high winds; once they peel off, the membrane edge can be lifted. In North America, ANSI/SPRI ES-1 is the standard used to test and rate roof edge systems, including copings, for wind resistance, and building codes reference it.