Walk on the wild side

When Manchester’s city councillors backed a plan to create a £3.5 million glazed link pavilion between the Manchester Town Hall extension and the adjacent Central Library, a crucial aspect of this vision was to permit ease of circulation for the million plus people using this connection every year.

Ian Simpson of architects Simpson Haugh and Partners worked with design-led structural and civil engineering firm Akt II and Eckersley O’Callaghan for the detailed structural engineering, to develop the striking and ambitious design. The project also presented itself as an opportunity to experiment with new design tools, technologies and fabrication methods.

The centrepiece of the 175m² pavilion is the ‘cloud’, a 30-tonne polished stainless-steel undulating monocoque roof, set carefully atop a vertically glazed wall of triple-layer, frameless structural glass panels of 7.2m in height. These are wedged into a shoe at the base, allowing a simply supported connection to the roof. The glass panels are joined with structural silicone, to act as a monolithic shell that resists lateral loads created by wind.

Dowsil 993 structural glazing silicone sealant was specified for the structural bonding of the glass panels, meeting the demands of the architects and also the build requirements. Used in the construction of the Burj Khalifa, Dowsil 993 sealant hasexce llent adhesion to a wide range of substrates, resistance to ozone and UV, and excellent stability through a wide temperature range.

This was also the first and only project in the UK where Dowsil 993 sealant has been used in a vertical application to achieve a 40mm butt joint.

Specified by facade contactor Waagner Biro, Dowsil 993 sealant in mid grey was applied by AEL, a Dow Quality Bond member, which provides an assurance that the applicator has been trained and audited to meet the highest quality standards set by Dow High Performance Building Solutions.