Dragon beam is a horizontal, diagonal
beam in the corner(s) of some traditional
timber-framed
Timber framing () and "post-and-beam" construction are traditional methods of building with heavy Beam (structure), timbers, creating structures using squared-off and carefully fitted and Woodworking joints, joined timbers with joints secure ...
buildings. The term is commonly used in both
hip roof
A hip roof, hip-roof or hipped roof, is a type of roof where all sides slope downward to the walls, usually with a fairly gentle slope, with variants including Tented roof, tented roofs and others. Thus, a hipped roof has no gables or other ve ...
framing and
jettying
Jettying (jetty, jutty, from Old French ''getee, jette'') is a building technique used in medieval timber framing, timber-frame buildings in which an upper floor projects beyond the dimensions of the floor below. This has the advantage of incr ...
. Older publications may use the synonyms dragging beam, dragging piece, dragging tie, dragon piece or dragon tie. Inconsistencies in modern usage are discussed below. In French it is called a or .
Etymology
The etymology of dragon is unclear. The term may be descended from German (a carrier), Danish (bearing beam, joist, girder) or Dutch (beam). The origin has also been proposed as a corruption of diagonal or diagon.
Hip roofs
The dragon beam lies parallel to and below a hip rafter and carries the rafter. The dragon beam is carried by the wall on the outer end and by a horizontal piece between the two walls on the inside end. There are conflicting usages for this term in the U.K. and U.S.A. (see below). The most common usage seems to be combination dragon beam/cross tie.
* A dragon beam lands on a dragon tie. (U.K.)
* A dragon tie lands on a cross-tie. (U.K.)
* A dragon beam lands on a dragon tie. (U.S.A.)
* "Dragon strut, dragon piece, dragon tie, dragon beam", (French: coyer) lands on a "dragon cross tie" (French: gousset). (U.S.A.)
* A dragon-piece lands on an angle-tie (U.K.)
Jetties
In buildings with
jetties
A jetty is a man-made structure that protrudes from land out into water. A jetty may serve as a breakwater, as a walkway, or both; or, in pairs, as a means of constricting a channel. The term derives from the French word ', "thrown", signif ...
on adjacent walls the dragon beam is a horizontal, diagonal beam projecting from a corner which supports the jetties. Sometimes the post below the dragon beam is called a dragon post.
[Harris, Richard. Discovering timber-framed buildings. 2d ed. Aylesbury: Shire Publications, 1979. 56.]
References
{{reflist
Timber framing
Medieval architecture
Structural system