Replaced rooflight
A replacement sloping roof light on the two-storey Glashaus office building in Cobham, Surrey, has been designed, manufactured and installed by Structura UK in a 12-week contract worth £190,000.
The design and neat appearance of the bespoke, energy efficient, eight-sided, 30.8mm-thick double glazed unit, which replaced a 25-year-old transparent acrylic thermoplastic roof light and blinds below, belies its detailed structural calculations and complex geometry of straight lines and curved steel frame. It consists of solar reflective glass panels in a variety of shapes, sizes and weights, and bronze powder coated, aluminium standard and hip mullions, capped by a 12-sided aluminium finial.
Structura UK removed the original roof light and erected a temporary roof structure of shrink-wrapped scaffolding about 16m square x 5m high. Under the company’s supervision, the existing steelwork had to be reinforced with new structural steelwork because it was too light to accept the weight of a glass roof. In addition, a new ring beam was installed, and a new upstand was created to interface with the external and internal ductwork.
The roof light’s glazing consists of an inner pane of 8.8mm thick clear laminated glass, a 16mm thick silver spacer bar with air filled cavity and an outer pane of 6mm thick Guardian Sunguard HP silver 43 toughened and heat-soak tested glass.
Water penetration tests were carried out to CWCT standards and satisfactorily completed to provide a fully watertight system.
