Fire Safety Solutions & Innovations
What has Been Defining Wall Systems Across the Country
By Karine Galla, Director, Product Management for Sto Corp.
(Editor’s Note: Karine Galla is Director of Product Management for Sto® Corp. She has more than 20 years of experience in product marketing in EIFS, stucco, air and moisture barriers, and other materials. Karine has a master’s degree from the University of Lyon, France. She is multilingual and holds AWCI’s EIFS Doing it Right and Building Envelope Doing it Right certifications, as well as the ISO Internal Lead Auditor certification from Georgia Tech.)
There is a long history with many significant fires in the late 19th and early 20th centuries that have resulted in much improved fire safety testing and systems in the United States today. Several major urban fires, such as the Great Chicago Fire of 1871 and the San Francisco Earthquake and Fire of 1906, exposed the vulnerabilities of wood-framed buildings. In response, early fire testing focused on masonry and concrete, which were recognized for their superior fire resistance. Organizations such as the National Fire Protection Association (NFPA), founded in 1869, emerged to create fire safety standards and advocate for fire-resistant construction.
By the mid-20th century, standardized fire tests became a key part of building regulations. The introduction of ASTM E119 in the 1920s established criteria for fire-resistant ratings of walls, floors, and roofs. As lightweight construction and synthetic materials gained popularity in the 1960s, concerns about fire spread and heat release rate grew, leading to stricter fire testing methods.
During the energy crisis of the 1970’s, there was a push to make wall systems and buildings more energy efficient, and with that a concern about their safety. As a result, The Uniform Building Code (UBC) adopted UBC 17-6, a full-scale test to evaluate the flammability of exterior walls containing foam plastic. This landmark test would eventually be adopted by the NFPA and renamed NFPA 285. NFPA 285 is an assembly test, not a component test. So, the emphasis shifted from how individual products perform to how the finished wall system performs.
By the late 20th century, high-rise fires such as the 1988 First Interstate Bank fire in Los Angeles, California, highlighted the risks of vertical fire spread along building façades, further reinforcing the need for assembly-based fire testing.
In 2017, the Grenfell Tower fire in London, England, was another pivotal moment in fire safety. Originating from a faulty refrigerator on the fourth floor that burst into flames, the fire ripped through the floor and raced up the side of the building at an unimaginable speed, feeding off the MCM cladding installed on the outside of the building. There were a lot of issues, such as flammable material used in the original building, smoke extraction device malfunctioning, water supply for the firefighters, and apartment doors that did not meet current fire resistance standard, which led to the tragedy.
In mere hours, the blaze claimed 72 lives and exposed critical flaws in the design and materials used in modern construction. This tragedy catalyzed sweeping changes in building regulations worldwide. Authorities and manufacturers alike recognized the urgency of designing wall systems that could actively mitigate fire risks.
In response, jurisdictions such as New York City (NYC) introduced stricter fire safety requirements. Section BC 718.2.6 of the NYC Building Code now mandates fireblocking in exterior wall assemblies containing combustible components, addressing concerns that assembly testing alone may not fully account for fire propagation risks. These new building codes compelled manufacturers to explore new solutions. They immediately began looking at existing products to see how they could be modified to enhance fire safety. But more importantly, they began looking at walls as an opportunity to layer in fire safety, just as they had layered in technology that helped reduce the risk of air and water intrusion.
As a result, new fire barrier solutions have emerged, including fire-resistant coatings, cementitious fireproofing, fire-resistant boards, and mineral wool-based fireblocking strategies such as lamellas. These technologies are increasingly being integrated into wall assemblies to help meet evolving building codes while balancing fire performance, energy efficiency, and design flexibility. By addressing fire risks at the system-design stage, modern wall assemblies are contributing to safer, more resilient buildings without compromising aesthetic or functional goals.
Modern exterior wall systems, including EIFS, are designed as integrated assemblies that combine air and water-resistive barriers, continuous insulation, and reinforced finishes. When properly specified and installed, these systems can meet applicable code requirements while supporting energy efficiency, moisture management, and fire performance. Their lightweight nature also makes them well-suited for both new construction and retrofit applications.
Over the past 30 years, EIFS has undergone a transformation, emerging as a versatile, high-performing cladding system. Applied in multiple layers over exterior sheathing, today’s EIFS with drainage provides outstanding insulation, moisture, and fire protection.
A complete, pre-engineered system performs more efficiently, reduces long-term costs, and is covered by a single warranty. It is easier and more affordable to transport, allows savings on maintenance and repair since damage can be repaired in targeted areas, with a layer of exterior continuous insulation, and it provides enhanced thermal efficiency.
Mineral wool is widely used in exterior wall assemblies for its non-combustible properties and reliable fire performance. Classified as non-combustible under ASTM E136, it offers low flame spread and zero smoke development characteristics and maintains performance at elevated temperatures.
Traditional mineral wool slabs are mechanically fastened to the structure, which can introduce thermal bridging and limit surface uniformity. Lamellas, also composed of mineral wool and classified as non-combustible, provide an alternative configuration. They can be adhered directly, removing the need for fasteners and minimizing thermal interruptions, while also allowing for a more planar surface.
These attributes can make lamellas a strong option in applications where both fire performance and façade aesthetics are important. These materials have been widely used in European façade systems for decades, providing a strong precedent for their performance in fire-resistive wall assemblies.
As fire safety requirements continue to evolve, designers must balance performance, sustainability, and risk mitigation. No single material provides a complete solution, reinforcing the importance of system-level design. Integrated wall assemblies that address fire, moisture, and thermal performance together are increasingly critical to achieving resilient, future-ready buildings.
