A braced timber diagrid pitched roof clad with lead panels
The dining hall is a singlestorey 20 x 10m space with a pitched roof, hipped at each end and covered with diamond-shaped lead panels.
The shape of the panels mirrors the timber diagrid roof structure which is visible inside the hall, set between diamond-shaped oak panels.
The walls are of solid brickwork in Flemish bond with pure hydraulic lime mortar joints. A series of precast concrete padstones set at 2.5m centres at the eaves are tied by wallplates of laminated veneer lumber.
The padstones support the diagrid roof of 400 x 100mm glulam beams with the lowest lamination of American white oak. The beams have 400mmdeep stainless-steel shoes fitted over their ends. Each diagrid connection is made by bolting four shoed beam ends to a four-sided, stainless steel node connector. To prevent lateral spread, a network of 16mm-diameter stainlesssteel tie rods run between the nodes, supporting 60mmdiameter stainless-steel props.
The diamond-shaped ceiling panels are set between the glulam beams with 15mm-wide shadow gaps.
They are faced with American white oak slats and lined with acoustic insulation.
A series of 175 x 50mm rafters is fixed with steel brackets to the beams, lined with insulation and braced with ply. Above the ply is a vented cavity formed by 50 x 50mm battens and an 18mm ply deck on which the lead panels rest.
Each panel was prefabricated from Code 5 lead worked round a diamond-shaped tapered ply panel, with a flashing skirt burned on along the two upper edges and supported by a thin stainless-steel plate.
The panels interlock; each panel rests on the flashing of the panel below.