Siderise protects Manhattan skyscraper with CW-FS120 Firestop system

Situated between Bryant Park and the Empire State Building in the Garment District, 989 6th Avenue is a 240-metre mixed-use tower designed by C3D Architecture. The concrete frame structure features a sleek glass curtain wall, open terraces and a dramatic multi-cylinder podium that contrasts strikingly with the classical façade of the neighbouring Haier Building.

The intricate unitised curtain wall façade was designed, engineered and fabricated by Bisam Façade and installed by Marvel Contracting. As part of its remit, Marvel Contracting worked closely with Siderise’s US distribution partner, namely Façades X, to procure a passive fire protection solution that exceeds the fire compartmentation requirements, while also facilitating a smooth installation process.

Siderise’s CW-FS120 Firestop was specified to provide floor-to-floor compartmentation, protecting the void space at the perimeter joint between the edge of the floor slab and the internal surface of the external wall assembly.

This solution offers a third party certified FT rating of up to three hours (resistance to fire spread and temperature rise on the non-fire side) when tested to ASTM E2307 as part of the CW Perimeter Barrier System. It has been independently tested to ensure L-rating compliance with the International Building Code.

Lamella core

Additionally, the vertical fibre stone wool Lamella core has been specifically engineered to withstand the demands of building and curtain wall movement on high-rise towers, boasting a 60-year design life.

In collaboration with façade contractor Bisam Façade and consultants at Socotec, Siderise prepared a thoroughly detailed technical submission for the perimeter fire barriers tailored to the project’s complex slab-edge geometry. Special attention was paid to the curved east elevation and its staggered floor edges to ensure continuous compression fit and long-term performance for design life movements.

To ensure this bespoke on-site work met high standards and followed manufacturer recommendations, Siderise Site Services assisted the Marvel Contracting installation team with project-specific training and benchmark installations. This support continued throughout the project with regular inspections conducted via the Siderise Inspection App.

*Further information is available online at www.siderise.com