29 August 2017

Meticulous conservation for ‘Masterpiece of Carpentry’

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Harmondsworth Great Barn, one of the nation's most important architectural treasures, is hailed as a ‘masterpiece of carpentry’ by English Heritage. The Grade 1-listed building has undergone a meticulous programme of conservation and repair by Ptolemy Dean Architects.

Assembled with the same skill and precision as Britain’s notable medieval churches and palaces, the Great Barn was built by Winchester College during the late medieval infrastructure boom as Europe recovered from the ravages of the Black Death.

Among majestic oak trusses are opportunities to admire a medieval timber design dating back to the reign of boy-king Henry VI and a time shortly after the death of Chaucer.

Using surveys and reports from English Heritage, Harmondsworth has not only allowed veteran carpenters to sharpen their skills, but provided an opportunity to train an apprentice in heritage carpentry.

Harmondsworth was one of England's most prosperous agricultural regions but, over the centuries, wheat, barley and fruit growing gave way to urban sprawl. The development of Heathrow Airport in the 1940s sounded the death-knell for agriculture in Middlesex, when all but one of the region's ancient barns were demolished.

The Great Barn is exceptionally rich in original oak timbers – some 98 per cent of which remain in place. It is more than 60 metres long, 12 metres wide and 11 metres tall, with 13 massive oak trusses supporting the vast, tiled roof. A complex lattice of colossal curved braces and beams above a ‘nave’ and a dozen chapel-like bays give the impression of a towering medieval church.

By 2006, rainwater had seeped into the fabric of the building, roof tiles had crumbled and weeds dominated its ancient timbers. The absence of a fire alarm system or fire-fighting equipment gave rise to serious concerns.

The Great Barn was acquired by English Heritage in 2012 and lovingly restored, providing an opportunity for the public to marvel at its magnificence, as well as gain a fascinating insight into the technology, method and sequence of its construction, and the craft skills used in its restoration and repair.

But while the Great Barn is lauded as Britain’s best-preserved and largest surviving medieval timber barn, it is once more under threat. Plans for the construction of a third runway at Heathrow Airport mean it is soon to be only metres away from the thunderous roar of planes leaving the tarmac.



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