Gable

This article is about the architectural feature. For other uses, see Gable (disambiguation).
A single-story house with three gables, although only two can be seen (highlighted in yellow). This intersection of gables is a cross gable roof
Gable roof at 176-178 St. John's Place between Sixth and Seventh Avenue in the Park Slope neighborhood of Brooklyn, New York City
Look up gable in Wiktionary, the free dictionary.

A gable is the generally triangular portion of a wall between the edges of a dual-pitched roof. The shape of the gable and how it is detailed depends on the structural system used (which is often related to climate and availability of materials) and aesthetic concerns. Thus the type of roof enclosing the volume dictates the shape of the gable. A gable wall or gable end more commonly refers to the entire wall, including the gable and the wall below it.

A variation of the gable is a crow-stepped gable, which has a stairstep design to accomplish the sloping portion. Crow-stepped gables were used in Scotland and England as early as the seventeenth century. Examples of the crow-stepped gable can be seen at Muchalls Castle and Monboddo House, both 17th century Scottish buildings. Other early examples are found in parts of Denmark and Sweden.

Gable ends of more recent buildings are often treated in the same way as the Classic pediment form. But unlike Classical structures, which operate through trabeation, the gable ends of many buildings are actually bearing-wall structures. Thus, the detailing can be ambiguous or misleading. (For an influential opinion on truth in architecture, see John Ruskin's The Seven Lamps of Architecture).

Gable style is also used in fabric structure design, with varying degree sloped roofs, dependent on how much snowfall is expected. Sharp gable roofs are a characteristic of the Gothic and classical Greek styles of architecture.[1]

Front-gabled and side-gabled

While a front-gabled building faces the street with its gable, a side-gabled building faces it with its cullis, meaning the ridge is parallel to the street. The terms are used in architecture and city planning to determine a building in its urban situation.

Side-gabled buildings are considered typical for German city streets in the medieval gothic period, while later Renaissance buildings, influenced by Italian art are often side-gabled. In America front-gabled houses as the Gablefront house were popular primarily between the early 19th century and 1920.

Drawbacks

The gable end roof is a poor design for hurricane regions, as it easily peels off in strong winds. When wind flows over a gable roof, the surface behaves like a wing. Lift is created on the leeward side of the roof. The flatter the roof the more likely this will happen. A steep roof tends to cause the wind to stall as it goes over the roof and breaks up the effect. The addition of a vertical fin to low pitched roofs can also help.[2] 35 deg is the effective pitch of a roof where uplift is achieved or not - below 35 deg then the roof is subject to uplift, above this then the roof is pushed down onto the wall plate.

See also

References

  1. ↑ Passmore, Augustine C.. "Twenty Styles of Architecture". Handbook of technical terms used in architecture and building and their allied trades and subjects,. London: Scott, Greenwood, and Co.;, 1904. 360. Print.
  2. ↑ Roof damage by hurricane force winds in Bermuda The Fabian Experience, September 2003, page 5, Mark Rowe, Department of Environmental Protection, Government of Bermuda
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