The major requirement of the structural repairs was to stabilise the roof trusses and prevent further spreading of the main hall walls. New steel trusses have been introduced to the existing structure to support the roof. The existing timber trusses have been left in place and after repair could be used to support the ceiling.

The ceiling plaster was in a very delicate state and it was feared the vibration of mending the roof's structure would cause it to collapse. During the repairs the plaster was supported with scaffolding and a timber framework was shaped to match the radius of the arch. The loose areas of plaster were bonded in position using plaster of Paris reinforced with stainless steel mesh.

The ceiling plaster is supported by timber ribs which, in turn, are supported by binders fixed between each of the roof trusses. The connections between the ribs, binders and trusses have been weakened by the movement of the roof and new fixings were introduced to ensure that the weight of the ceiling was safely transferred to the roof trusses.