A cockscomb is a tapered rowlock course above a window or door opening in which the centre is clearly raised, or the whole course runs in an arch. The bricks, laid on edge, fan out from the centre like the comb of a cockerel — hence the name. The cockscomb takes up the weight of the masonry above and spreads it to the sides of the opening.
How it works
Above an opening in a wall, the weight of the masonry must be received and led around the opening. The cockscomb does this like a light relieving arch:
- The bricks stand on edge and are stacked in a wedge shape
- The tapered, raised form creates an arching action
- The load of the masonry above is carried off to the reveals (the sides of the opening)
- A steel lintel or timber beam is often placed beneath the cockscomb for extra security
Applications
The cockscomb is used both structurally and decoratively:
- Above windows and doors in masonry façades
- As decorative masonry — the cockscomb gives a façade a craft-like, classic appearance
- In restoration of older façades where the original cockscomb is preserved or rebuilt
- In combination with a lintel for wider openings
Points to watch
- A cockscomb on its own can carry only a limited span; for wider openings a supporting lintel is necessary
- The pointing matters: the wedge shape of the joints partly determines the arching action
- Cracks above an opening may indicate that the cockscomb or lintel has been overloaded
Related terms
- Rowlock course
- Masonry
- Lintel
- Arch
- Reveal
Want to learn more about construction terms? Visit our knowledge base at fredsdiyplans.com.