A cruck or crook frame is a curved

timber Lumber is wood that has been processed into dimensional lumber, including beams and planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, w ...

, one of a pair, which support the

roof A roof ( : roofs or rooves) is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights, providing protection against rain, snow, sunlight, extremes of t ...

of a

building A building, or edifice, is an enclosed structure with a roof and walls standing more or less permanently in one place, such as a house or factory (although there's also portable buildings). Buildings come in a variety of sizes, shapes, and func ...

, historically used in England and Wales. This type of

timber framing Timber framing (german: Holzfachwerk) and "post-and-beam" construction are traditional methods of building with heavy timbers, creating structures using squared-off and carefully fitted and joined timbers with joints secured by large woode ...

consists of long, generally naturally curved, timber members that lean inwards and form the ridge of the roof. These posts are then generally secured by a horizontal beam which then forms an "A" shape. Several of these "crooks" are constructed on the ground and then lifted into position. They are then joined together by either solid walls or cross beams which aid in preventing 'racking' (the action of each individual frame going out of square with the rest of the frame, and thus risking collapse).

Etymology

The term ''crook'' or ''cruck'' comes from

Middle English Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old Englis ...

', from

Old Norse Old Norse, Old Nordic, or Old Scandinavian, is a stage of development of North Germanic dialects before their final divergence into separate Nordic languages. Old Norse was spoken by inhabitants of Scandinavia and their overseas settlement ...

', meaning "hook". This is also the origin of the word "crooked", meaning bent, twisted or deformed, and also the crook used by

shepherd A shepherd or sheepherder is a person who tends, herds, feeds, or guards flocks of sheep. ''Shepherd'' derives from Old English ''sceaphierde (''sceap'' 'sheep' + ''hierde'' ' herder'). ''Shepherding is one of the world's oldest occupations, ...

s and symbolically by bishops.

Use

Crucks were chiefly used in the

medieval In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...

period for structures such as houses and large tithe barns, which were entirely timber-framed. They were also often used for the roofs of stone-walled buildings such as churches. However, these bent timbers were comparatively rare, as they were also in high demand for the shipbuilding industry. Where naturally curved timbers were convenient and available, carpenters continued to use them at much later dates. For instance, base crucks are found in the roofs of the residential range of Staple Inn Buildings, Nos. 337 – 338,

High Holborn High Holborn ( ) is a street in Holborn and Farringdon Without, Central London, which forms a part of the A40 route from London to Fishguard. It starts in the west at the eastern end of St Giles High Street and runs past the Kingsway and S ...

, London. This is dated by documented records to 1586, with significant alterations in 1886 (under

Alfred Waterhouse Alfred Waterhouse (19 July 1830 – 22 August 1905) was an English architect, particularly associated with the Victorian Gothic Revival architecture, although he designed using other architectural styles as well. He is perhaps best known ...

) and further restorations in 1936, and 1954–55. Despite these changes Cecil Hewett, an authority on English Historic Carpentry, has stated that these 16th-century crucks are original. The large main barn of the manor house Barlow Woodseats Hall features what is claimed to be the longest continuously roofed cruck barn in

Derbyshire Derbyshire ( ) is a ceremonial county in the East Midlands, England. It includes much of the Peak District National Park, the southern end of the Pennine range of hills and part of the National Forest. It borders Greater Manchester to the nor ...

, and possibly even in the United Kingdom. An example of a

Yorkshire Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a Historic counties of England, historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other Eng ...

cruck barn complete with a heather-

thatched roof Thatching is the craft of building a roof with dry vegetation such as straw, water reed, sedge (''Cladium mariscus''), rushes, heather, or palm branches, layering the vegetation so as to shed water away from the inner roof. Since the bulk o ...

can be found in

Appletreewick Appletreewick is a village and civil parish in the Craven district of North Yorkshire, England, north-east of Skipton, from Skipton railway station and from Leeds Bradford International Airport. Appletreewick is in Wharfedale in the Yor ...

. The crucks or cruck "blades" are a single oak tree riven (split) in two to form an equally shaped A frame. Rare examples of cruck framing are found on continental Europe such as in Belgium, Flanders, Northern France and the

Corrèze Corrèze (; oc, Corresa) is a department in France, named after the river Corrèze which runs through it. Although its prefecture is Tulle, its most populated city is Brive-la-Gaillarde. Corrèze is located in the Nouvelle-Aquitaine regio ...

region of France. No cruck frames are known to have been built in North America though there are rare examples of what may be an upper cruck or knee rafters.

Revival

During the current revival of green-oak framing for new building work, which has occurred mainly since approximately 1980 in the UK, genuine cruck frames have quite often been included in traditionally carpentered structures. There are also some fine, historically authentic reconstructions. For instance, Tithe Barn, Pilton,

Glastonbury Glastonbury (, ) is a town and civil parish in Somerset, England, situated at a dry point on the low-lying Somerset Levels, south of Bristol. The town, which is in the Mendip district, had a population of 8,932 in the 2011 census. Glastonbur ...

, whose original roof was destroyed by lightning, has been carefully rebuilt in 2005 from curved oaks. The necessary trees were sought out, using special templates, in English woodlands.

Types

# True cruck or full cruck: The blades, straight or curved, extend from a foundation near the ground to the ridge. A full cruck does not need a tie beam and may be called a "full cruck - open" or with a tie beam a "full cruck - closed". # Base cruck: The tops of the blades are truncated by the first transverse member such as by a tie beam. # Raised cruck: The blades land on masonry wall and extend to ridge. # Middle cruck: The blades land on masonry wall and are truncated by collar beam. # Upper cruck: The blades land on tie beam, very similar to knee rafters. # Jointed cruck: The blades made from two pieces joined near eaves. They can be joined in at least five ways. The apex of a cruck frame also helps to define the style and region of the cruck. Different types include the butt apex, halved, housed, yoke, and crossed forms.

References

External links

Cruck database

Black and White Timber Framed houses
{{Woodworking Woodworking Vernacular architecture Timber framing Structural system

Etymology

Use

Revival

Types

See also

References

Further reading

External links