When NFPA 285 and its requirements restricting the spread of fire for full building assemblies began to be enforced several years ago, the design industry scrambled to find compliant systems. 

Then in 2022, New York City enacted even stricter fire protection requirements. Out of concern for the high density of high-rise structures in the city, the code requires non-combustible fireblocking to be installed even when wall assemblies comply with NFPA 285. 

For example, fireblocking must be used within concealed spaces of exterior wall coverings, and as barriers between floors and occupancy groups, both horizontally and vertically. It is also required around wall openings like windows, doors, vents and pipes, and in alignment with slab edges. 

Having essentially adapted to designing NFPA-compliant assemblies, Big Apple architects are now facing the challenge of designing to the newer and stricter NYC code. 

Sto Fireblocking is positioned to make things a little easier for New York City building owners and designers.

Foam plastic insulation is an effective and popular way to create continuous insulation and achieve a high level of thermal performance for building enclosures. However, architects have traditionally struggled with finding foam plastic insulation products that also meet NFPA 285 fire resistance requirements. 

Solving this pain point, Sto Fireblocking—fully compliant and tested in accordance with NFPA 285—is made with Sto Laemellas, a non-combustible fireblocking product available in various thicknesses to match the adjacent foam plastic insulation. 

“The system uses adhered mineral wool lamellas that are penetration-free, avoiding mechanical fasteners that create thermal bridges. Because it integrates directly with foam plastic continuous insulation assemblies, architects can design fully code-compliant façades without sacrificing thermal continuity,” explains Karine Galla, director, product management, Sto Corp.   

Sto Lamellas are precision-cut strips in varying thicknesses. The mineral wool adheres to other materials with no penetration and no thermal bridges. It seamlessly matches adjacent foam insulation thereby creating a flush façade surface. 

Many products have difficulty achieving NFPA 285 compliance because the code does not certify components, only full systems. Sto Fireblocking is unique in that it was designed and tested with EIFS, rainscreen and ci systems as part of a complete façade assembly.