The deadliest single-building fire in U.S. history as documented by the National Fire Protection Association occurred on Dec. 30, 1903, at the Iroquois Theatre in Chicago, where 602 people died during a performance of Mr. Blue Beard, a popular musical. The fire curtain in place at the theater failed to deploy when it became snagged on a light reflector that stuck out under the proscenium arch.The fire started when sparks from a short circuit on an arc light ignited a muslin curtain. Other factors contributed to the tragedy: There were no exit signs or emergency lighting; exit doors opened inward; the curtain had not been tested; some exits were locked; and when performers and stagehands escaped through a back exit, a brisk winter wind swept in and fueled the lethal blaze.
Codes and standards have improved markedly since that tragedy. So too have fire curtains. But as codes and standards have been updated and new applications have emerged, some construction officials have expressed confusion about codes and where fire and smoke protective curtains can be installed. As more facility managers, building owners and contractors retrofit existing buildings, it’s essential to know where fire curtains can be used and which standards and codes apply.
Quick History Lesson
Fire and smoke protective curtains date back to the late 1600s. A fire at the Drury Lane Theater in London in 1672 prompted the owners to rebuild with two safety features: a large water tank perched on the roof to douse potential stage fires and the world’s first known safety curtain—an iron curtain mounted in front of the stage to protect the audience from backstage fires. Fire protection curtain assemblies continued to be installed over the years with new regulations requiring they be tested prior to every performance at theaters. In the 1980s, engineers and architects in Europe discovered other commercial applications for fire and smoke protective curtains. It took several decades, but more commercial enterprises in the U.S. also started to install curtains. As curtains have become more commonplace, regulatory agencies have updated codes and standards regarding their use.
What Are They?
A fire and smoke protective curtain assembly is a flexible heat resistant fabric infused with a coating to limit air infiltration. Curtains limit the effects of unimpeded migration of fire and/or smoke and can be fixed in place, automatically deploy upon receiving a signal from a smoke protection device or gravity deploy on a loss of power. They can also be concealed above a ceiling to offer a hidden layer of fire protection and can be weighted to assist with deployment and limit deflection caused by air movement. They are not, however, an equivalent alternative to a fire-resistant floor or wall assembly.
Codes and Standards
Test standards from Underwriters Laboratories that apply to smoke and fire protective curtains include UL 10D, UL 1784 and UL 864. UL 10D and UL 1784 were recently introduced to the U.S. In 2014, UL 10D was approved and evaluates fire protective curtain assemblies intended to provide supplemental, passive fire protection as part of an engineered fire protection system. UL 1784 tests assemblies for air leakage of door assemblies and other protectives. UL 864 addresses requirements for control units and accessories for fire alarm systems.
NFPA 80 regulates the installation and maintenance of assemblies and devices used to protect openings in walls, floors and ceilings against the spread of fire within or into buildings. The 2016 edition of NFPA 80 added a new definition for fire protective curtain assemblies. NFPA 80, Section 21.1.1, clarifies that the current generation of curtain assemblies are not to be confused with fabric fire safety curtains, which are specifically intended for protection of proscenium openings. Fabric fire safety curtain assemblies are part of the passive fire-resistive separation between the stage and the audience seating area. They are intended to provide at least 20 minutes of protection so audiences can safely evacuate. For recognition as proscenium opening protection, curtains must meet the requirements of the 2016 Edition of NFPA 80 Chapter 20, which deals specifically with fabric curtains.
Where to Use Them
With the codes and standards currently in place, compliant applications for curtains include draft curtains for escalators, stair openings and warehouse storage areas; smoke partitions, including opening protectives; elevator hoist-ways to limit smoke migration; non-egress opening protectives in corridors that require a 20-minute rating and smoke barriers; proscenium openings (provided the curtains also meet the requirements of Chapter 20 of 2016 NFPA 80); and service counter fire doors where 20-minute opening protectives are allowed. A UL Task Group is also considering the inclusion of horizontal sliding applications, which will create even more opportunities to use curtains.
Code compliance, performance and aesthetic characteristics, integration with an engineered smoke control system and available options should be considered when evaluating the use of smoke and fire curtain assemblies in commercial buildings. Options include firefighters’ override, sizing, orientation, guide systems, fabric materials and siren/strobe light capabilities.
White Paper about Codes and Standards Related to Fire and Smoke Protective Curtains
The BILCO Co., New Haven, Conn., a manufacturer of specialty access products, recently wrote a white paper based on research by code expert Vickie Lovell and Douglas Evans, P.E., Fellow of the Society of Fire Protection Engineers, that details codes and standards construction companies and others need to know about installing fire and smoke protective curtains, as well as applications where curtains can and should be installed. The full white paper can be accessed on the BILCO website or via email.
PHOTOS: BILCO Co.