Cathedrals can be busy places. Thousands of visitors trooping through a medieval structure takes its toll, while demands of modern life and regulation can compromise the use of space.
This is exactly why Wells Cathedral embarked on its Cathedral Development Project 12 years ago. The aim of the scheme was to reconcile a number of potentially conflicting requirements; including managing the large numbers of visitors (450,000 a year), clearing cloisters of recent temporary accretions and meeting the needs of the cathedrial’s multifarious functions and activities, notably education and music.
“Some areas cannot be opened up for use by the public or even retained as glorious, tranquil spaces because they have been pressed into service for storage or other temporary usage due to lack of any alternative room,” a cathedral spokesperson said.
The plan’s objective was to widen access to the cathedral, allowing people to visit more parts of the building and opening up “more of the meaning of the place”. “We wanted to provide a better experience for everyone,” the spokesperson said.
The solution to all these demands from architects Purcell Miller Tritton involved four new structures and consequently detailed planning and design negotiations with the local authority, the Cathedrals Fabric Commission for England, and English Heritage.
Two of the new buildings are on the cathedral’s ‘camery’ – the name given to a secluded spot next to a bishop’s palace. One of these is a striking oak frame structure which recalls medieval build traditions.
Built by Carpenter Oak, the structure takes in three different rooms, accommodating the Cathedral Education Centre, the music department with two choir practice rooms, and visitor toilets.
Arched brace trusses were specified, a method often used by Carpenter Oak but which is more labour intensive than common framing. The reason for this choice was primarily aesthetic, as the arched brace gives for an uninterrupted view to the ceiling and a bigger open space without any cluttering from horizontal bracing.
“Your eye goes straight up because there is nothing cutting horizontally across the building,” said Carpenter Oak sales manager Andy Parker. “You often see them used in buildings that have external buttresses.”
This construction method involves mortise and tenon joints across the whole length of the curved sections, with oak pegs taking the force of the load.
But arched braces are prone to spreading, so the project engineer specified a small number of steel bolts. Each section has two bolts secured to adjacent straight rafters.
“Because the arched braces are thin sections, the wood is also rather prone to damaging and split so we had to put in dry timber. And we hold a significant stock of curved dry timber for just this reason,” said Porter.
Timber specification, he added, is hugely important to the end product, as is the quality of the joints. In the camery a variety were used, including chevron joints where sections butt up against each other to counter possible twisting.
Further interesting and complex features of the design included the fact that the architects specified two pitches in the structure. The steep internal pitch is contrasted by a lower external incline to match the other new camery building nearby. This unusual combination involved doubling up some of the structure.
Carpenter Oak also completed an external walkway called the pettis link, which links the camery to other parts of the cathedral.
In all, the construction of the oak frame took 3,300 yard hours (19 weeks) to make, with a further 500 hours spent on the cathedral site.
Appropriately enough given one of its uses, the new buildings form the shape of a grand piano due to the triangular nature of the site, though this was not specifically intended in the design process.
The cathedral did specify the use of traditional crafts
methods and materials within the new buildings and according to project architect Chris Cotton the structure of the education room will serve as a “useful tool for teaching Cathedral school parties about the craftsmanship of timber framing”. But, he maintained, for all its use of techniques that would have been familiar with the cathedral’s original builders, camery also has a distinctly contemporary feel.
Meanwhile, for Carpenter Oak, the Wells project reinforces its reputation in church architecture, following previous work at St Dominic’s Priory in Hampshire and St Mary’s Church, Isle of Skye, both of which featured arched timber brace trusses.
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Keywords: Carpenter Oak and Woodland
