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Timber Roof Construction

Timber was the essential material for roofs. RaftersGlossary Term were covered by slate, tile or thatch, or by lead when funds permitted. Early roofs still remain in some churches, recognisable from the steep profile created by long raftersGlossary Term; the whole sometimes distorted because of the absence of longitudinal bracing. The system of principal raftersGlossary Term which divide the roof into bays, with horizontal strengthening provided by purlins (timbers at right angles to the raftersGlossary Term), created a double-frame roof.

The Cruck was an alternative form, often used to span the shorter widths of domestic buildings. Pairs of stout curved timbers rising from the baseGlossary Term or lower part of the wall provide the main framework for the roof in a series of bays.

Timber roofs achieved great sophistication in the C14 and C15, using a variety of techniques to cover wide spans. The centrally braced Crown Post roof was developed, and from the 14th century the Hammerbeam roof provided the means for a spectacular timber covering for wider spaces. More common in the 15th century was the Arch-Brace roof, often used as an elegant means of spanning an open hall. Because of later alterations, and especially the insertion of floors and ceilings in former hall houses, medieval timber roofs can now only rarely be appreciated in the form they were intended to be seen. In spaces intended for public show the different elements were often emphasised by mouldings or carved detail; curved bracing between the raftersGlossary Term could add to the decorative effect.