Project: Restoration of Medieval vaulted roof
Location: Ansty, Wiltshire
Awards: Civic Trust Award 2002
The manor of Ansty was granted to the order of the Knights Hospitallers of St. John of Jerusalem by Walter de Turberville in 1210-11. The ancient barn is built on the site of a ‘Commandery’, the mediaeval headquarters of the Order, where it is thought that the original building had been built as a hospice for pilgrims.
From the year 1211 the Knights Hospitaller settled in Ansty forming a small ‘Commandery’, comprising the Commander or Preceptor, two Knights, a Chaplain, three minor clerics, the local Commander’s Esquire and six servants. It is thought that an original hospice was replaced by a large building, probably a banqueting house, in 1596. Despite a fire in 1922 which destroyed the roof, the building was reconstructed in 2001 including the restoration of the vaulted roof, which won a Civic Trust award in 2002.
After considerable research as the timber frame specialists, a series of nine arch braced trusses with separate raised collars was decided on.The striking shallow arch brace trusses are approximately 30 meters long and 6m wide with the ridge rising 6m above the wall plate. Compared to trusses with a tie beam, arch braced trusses are prone to spread, pushing the walls out. When a new building is commissioned, this can be overcome by designing in adjacent braced structures, or buttresses as restraints to the walls, or alternatively steel can be selectively inserted to minimise the effect (see our images of Wells Cathedral). In the case of this structure, providing new buttressing was clearly not an option, meaning that the threat to the ancient walls was significant. As a result, having constructed these trusses, the bases were rested on specially designed Teflon pads to allow a certain amount of settling in without asking the walls to move to accommodate excessive outward forces.