World of Glass, St Helens Geoffrey Reid Associates
The exhibition spaces of the museum are enclosed in brick halls while public and circulation spaces - ticket office, gallery, and restaurant - flow around them in a 'pavilion' of which the walls and perimeter edge of the roof are formed of structurally bolted glass.
At the entrance, the glass wall is 47m long and 6m high. It is formed of a lower row of double-glazed units, approximately 4m high and 2m wide, and an upper row of single-glazed units, 2m high and 4m wide. A series of planar stainless-steel castings and structural bolts connect the glass units to a 532mm wide glass fin. The castings accommodate the difference in thickness between the single- and double-glazed units.
Each fin is clamped at its base to a pair of back-to-back steel angles, a connection which is cleverly concealed within a heating and ventilation trench running at the base of the wall and covered with galvanised steel grilles.
At the eaves the roof edge is formed of 4 x 1m wide panels of 18mm laminated glass with an 80 per cent dot frit; they rest on the glass wall with a butt joint which is secured with silicone. The other edge is bolted with planar bolts and stainless steel angles to a steel plate welded to the roof structure.
The pavilion is roofed with a steel deck supported by 203 x 133mm universal beams which rest on a series of 400mm-diameter steel columns. The structure and the suspended ceiling below it are successively cut back as they approach the eaves, increasing the amount of light reaching the inner spaces and emphasising the transparency of the glass edge to the roof.