The atrium at London's 15 Sloane Square is a remarkable structure that features probably the longest glass beams ever used, each spanning almost 10 metres. True to the design aims, the glass atrium features an all-glass roof which positively floods the interior of the deep plan offices with light, keeping visual obstructions to a minimum.

The new building, of which the atrium is the main feature, has been constructed behind an elegant retained facade. The atrium starts at first floor level as the offices have been built above retail. This bespoke glass structure was designed by architects Paul Davis & Partners and AKT, and realised by FA Firman as a supply and fit operation. The builder was Sir Robert McAlpine and Dewhurst McFarlane was involved to prove the design.

The glazed roof measures 10 metres by 9 metres and is supported on four glass beams, each spanning almost 10m. The beams are spaced about 1.9m apart. Sitting on top of each of the beams between them are double glazed panels.

The beams were brought to site as fully fabricated units and craned into position to be fixed onto their stainless steel supports.

As toughened glass sheets are only available in up to 6 metre lengths, the beams were made of four sheets of 15mm Pilkington toughened glass laminated together in an overlapping arrangement. Firman's used Uvekol’s cold pour laminate process, which cures under UV light.

The beams are 830mm deep in the centre narrowing to 400mm at both ends. They were developed to support the roof with no mechanical fixings, the structural tape and glazing compound between the sheets taking all the weight. Transparent acrylic bolts were incorporated at a late stage as a safety feature.

Clear perspex blocks are used to space the vertical glazing from the edge of the slabs and to support the glazing at the top. The double glazed units were constructed using 12mm toughened glass outer panel with a 12mm void, then 10mm toughened glass bonded to 12.8mm low E laminated glass inside. The glass roof is designed to support the weight of maintenance staff above.

The walls to the atrium are again fully glazed in storey height glass panels fixed only at the corners. Firman's also supplied balustrading for the project. FA Firman, tel. 01708 374534, www.firmanglass.com

Source

Glass Age