Siderise safeguards new Manhattan skyscraper with CW-FS120 Firestop system

Siderise CW-FS120 Firestop for Curtain Walls is now being installed at 989 6th Avenue—delivering robust passive fire protection for this dynamic new 73-story development in the heart of Manhattan.

Situated between Bryant Park and the Empire State Building in the Garment District, 989 6th Avenue is a 240-meter 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 neighboring Haier Building.

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

Siderise 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. It 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 also been independently tested to ensure L-rating compliance with the International Building Code (IBC). Additionally, its unique vertical-fibre stone wool Lamella core was specifically engineered to stand up to 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 submittal 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 onsite work met high standards and followed manufacturer recommendations, Siderise Site Services assisted the Marvel installation team with project specific training and benchmark installations. This support continued throughout the project with regular inspections conducted via the Siderise Inspection App.