The 300 m long brick facade of Michael Hopkins and Partners' Forum library and cultural complex in Norwich is notable for having no expansion joints. Reinforced concrete corbels clamp the three-storey brick horseshoe wall to the concrete superstructure to ensure movements occur simultaneously. The wall is 1.5 bricks thick and bears some of the building's structural load. The Ibstock bricks were chosen for their low absorbency rate and a lime mortar specified by Michael Hopkins was used to ensure that the bricks will not crack when the concrete frame moves. The bricks are 19 mm longer than standard bricks, because this suited the geometry of the parapets. It also fitted in with the scale of the town hall, which has 300 mm long bricks.
The bricks were tested to ensure that their compressive strength wasn't exceeded by the compressive stresses of the wall. They also had to withstand horizontal wind loads and longitudinal movements and stresses. The brick parapets at the front of the building have no restraining corbels and are particularly prone to thermal variations. As a result, there are movement joints in the brickwork.
Architect Michael Hopkins and Partners Structural engineer Whitby Bird & Partners Quantity surveyor Turner & Townsend Main and brick contractor RG Carter Brick supplier Ibstock