Barns and Medieval Carpentry

THE GREAT BARNS

Today it is common to refer to any large farm building as a barn. However the medieval barn had a very specific place in the agricultural process. They were used for storing crops after the harvest when the barns were stacked to the apex of the roof with sheaves of wheat or barley. This explains the ‘horkey bough’ attached to the collar beam in the Wheat Barn. When the last cartload of the harvest came in from the fields, it was dressed with green boughs, one of which was tied to the roof to ensure good fortune and a good harvest the following year. The great doors are designed so that a loaded waggon could enter the porch or midstrey, be emptied and then leave through the lower doors at the rear.

Once gathered in the crop had to be threshed and winnowed which was done on the threshing floor between the doors, the cross draught being important to separate the grain from the chaff. The grain was then stored in a granary.

Great aisled barns have been described as the ‘cathedrals’ of timber building, there being a physical resemblance with their huge dimly lit interior spaces and a technological one inasmuch as they were the supreme achievements of the carpenter’s craft. They also resemble churches in that they have a central nave and side aisles, an arrangement devised to solve the problem of supporting a roof over larger areas than would be possible with single span beams. Both the Cressing barns date from the 13th century, and exhibit features typical of the carpentry of the period. These include straight timbers of square section joined with notched-lap joints on the cross frames, and the use of passing braces running below the rafters across the posts and tie-beams to provide transverse strength.

The timbers were obtained from woodland which was carefully managed to produce fast-grown straight oak trees. The trees were carefully selected so that they matched the size of timber required as closely as possible, and reduced the carpenter’s labour in squaring them up to a minimum. The timber was used green when the oak is easier to work, and was allowed to season in the finished building. Each of the barns would probably have been completed in a single building season between March and November. There were approximately 1200 joints to be cut in the fabrication of just one of the barns. The barns were roofed from the first with tiles slightly larger than those in use today. Each barn has about 45,000 tiles weighing about 55 tons.

Research has shown that although both the Cressing barns differ, the essential measurements of their plans and elevation are multiples or simple fractions of a medieval unit of measurement known variously as the rod, pole or perch (1612 feet, 5.03m). Furthermore, both the plans and cross-sections were generated by the use of strict geometry, using straight edge and dividers. This was repeatable full size using cords and pegs in a framing yard. Geometrical design has previously been recognized in medieval churches, but not in barns. Its discovery highlights the superior quality of these buildings, and is not wholly unexpected in work carried out for the Knights Templar.

 CARPENTRY TECHNIQUES AND JOINTS

Forty years ago the generally held belief was that few timber buildings pre-dated 1400 because they could not have survived over such a long period of time. Research and the development of scientific dating methods have shown this to be incorrect. Oak can certainly survive at least 900 years which is the approximate age of Greensted church, the oldest timber structure still standing in this country. Oak nearer 5000 years old has been found in archaeological deposits. Essex and Cressing Temple have occupied a very important place in this research into timber buildings. It was in Essex that Cecil Hewett carried out his pioneering studies of timber-framed buildings. He identified stylistic and technological variations in them, and gradually established a basic chronology for the development of carpentry techniques. As scientific dating methods became available they confirmed most of Hewett’s findings. At Cressing, he recognised that the carpentry involved was very different from that which post-dated c.1300, and it is from these first clues that we have now become able to date 12th and 13th-century timber frames.

The distinctive features we now recognise as 13th century are the use of straight square-section timber, passing braces, and certain types of joints and methods of assembly. The Wheat Barn presents a striking contrast with the more common later barns built with curved timbers of board-like cross section. The change to this type of carpentry style occurred soon after 1300, reaching a peak during the 14th century when we find multiple curved bracing patterns used for decorative purposes. At the same time, the crown-post roof became widespread, superseding the earlier roof with passing braces.

Joints that are characteristic of the 13th century and early 14th century are side lap joints and splayed scarf joints. Side lap joints can be seen in both barns. The earliest form is the notched-lap to be seen in the Barley Barn. This had been in use for at least a century when that barn was built. A more sophisticated form of the joint, the secret notched-lap, appears in the Wheat Barn. The notch, which serves to resist lateral withdrawal, was concealed by recessing it below the surface of the timber. Similar joints are found in the nave roof of Wells cathedral immediately after 1213. In the 14th century, lap joints went out of use except in roofs, and mortice and tenon joints were used almost exclusively for framing.

A scarf joint is used to join two timbers end to end when one is of insufficient length. Splayed scarf joints are typical of the 13th and early 14th century. They are somewhat difficult and therefore expensive to make. A fine example can be seen in the arcade plate at the east end of the Wheat Barn. In the later 14th century, edge-halved scarf joints, in which the timbers are halved along their length, replaced the splayed scarf joints. From the end of the 16th century, the simpler and cheaper face-halved scarf joints were used, making the scarf joint a very valuable dating indicator. Examples of both these later types of scarf joints can be found in the two barns.

The way in which the heads of the main posts were treated is well illustrated in the barns. Three phases of development can be observed, all having dating significance. In the earliest phase, which can be seen in the Barley Barn, the posts are the same thickness as the horizontal arcade plates which rest on them. In the Wheat Barn, the post is thicker than the plate and part of it, an upstand, projects upwards against the edge of the plate. Both these techniques are typical of pre-1300 work. Elsewhere in the barns, where the outer walls have been rebuilt in the 15th century, there is the common type of late medieval post the top of which is made wider to produce a projecting top or “jowl”. This provides the base for an upward projecting tenon which can be jointed into the transverse tie-beam, .

What becomes apparent when we look at these great buildings is the high level of skill and expertise that went into their construction. Most of the original features mentioned above were obsolete by about 1300 and therefore we are seeing the culmination of a long tradition. The Cressing buildings are the forerunners of the many later barns that survive in Essex and elsewhere. Regrettably few of these barns are open to the public, but the Grange Barn at Coggeshall can be visited. This was built after the Barley Barn and before the Wheat Barn, but was much altered in the 14th century. At Widdington near Saffron Walden the mid-14th century Priors Hall Barn is open to the public. Another one that can be visited is the 15th-century Monks Barn at Netteswelbury, Harlow. Such buildings are a valuable part of our national heritage and a reminder of the skill and craftsmanship of our forebears.

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