Cruck construction is a form of timber-framed structure which uses pairs of long, curved timbers, known as blades, that go from the top of the building to the ground and transfer the roof load to the ground. The cruck blades, which incline towards each other and are often matched halves of the same tree, are joined at or near the top of the building by a ‘collar’ or tie-beam to form an ‘A-frame. This type of construction was used for both houses and barns. Cruck barns were popular in medieval times for use as indoor threshing areas. Later difficulties in modernising cruck houses by adding first floor rooms resulted in some being downgraded to farm use or the house being raised and re-roofed with the crucks retained in situ or reused as structural members in other buildings.

Box construction is a form of timber-framed structure where the main horizontal and vertical timbers are joined at right angles to each other using cross tie beams to form the structural frame of the building. The roof is a separate structural element whose weight is borne by the external walls. The material used to fill in panels formed by the ‘box’ tended to vary from area to area across the country and included wattle-and-daub or lath-and-plaster, and later brick. Box construction became more popular than cruck because it allowed the building of upper floors (a particular advantage in crowded town centres) and made it much easier to extend the building by adding extra wings.

Sources

Early Modern Radley: People, Land and Buildings 1547-1768, Radley History Club, 2014

Domestic 1: Vernacular Houses Listing Selection Guide, Historic England, 2017, p. 5

Cruck frame buildings, woodlands.co.uk, 2007

Traditional Timber Framing – a brief introduction, University of the West of England, 2008, Section 4