Always add a dpc beneath the coping - this will protect the wall from water penetration around the joints in the coping. Flexible high bond impermeable materials are suitable for this lightly-loaded situation, but two courses of slate laid to break joint can also be used. Under brick cappings, slates or tiles can be used as a dpc (a separate flexible dpc should be included under tiles unless special dpc tiles are used). Slates and tile dpcs are also intended to shed rainwater clear of the wall and should project about 45 mm. In very sheltered areas (or when frost resistant materials are used throughout the wall) it is possible to use a rigid dpc with minimal overhang, or even just a flexible dpc.
Coping overhangs should be a minimum of 45 mm and be provided with a drip. In less exposed locations, or if frost resistant materials have been used throughout the wall, the need for protection against rainwater is not so great and smaller overhangs may be acceptable.
information extracted from: http://cig.bre.co.uk/nsdl/docs/fsw_doc.htm
for more indepth information on coping google http://www.ibstock.com/pdfs/architects/coping-and-capping.pdf
this is a stretcher bond sometimes called the running bond. this is th main structure used for half brick walls (or single skin walls),
thickness has very limited potential and is not considered stable above 725mm high, even in a very sheltered location.A wall on such a site should be no higher than 1925mm even if it is one brick thick (215mm), and in a very exposed location this drops to 1075mm
in this particular case this wall is in an urban area with many buildings shelding it so it is not often exposed to high winds. Designing for a worst case scenario would be uneconomic in most instances, but designing for an average exposure would be dangerous.
informaton extracted from : http://www.brick.org.uk/freestanding-walls.html
