Proscenium curtains
NFPA 101 Paragraph 12.4.6.7.1, “Proscenium Openings,” allows proscenium openings to be protected by a listed, minimum 20-minute fire curtain complying with NFPA 80. This allowance is also recognized in IBC Section 410.3.5, “Proscenium Curtain.” Only fire- and smoke-protective curtain assemblies meeting the requirements of NFPA 80 Chapter 20, “Fabric Fire Safety Curtains,” can be used as fabric fire safety curtain assemblies to protect proscenium openings.
NFPA 80 Section 21.1.1 also clarifies the current generation of fire- and smoke-protective curtain assemblies are not to be confused with fabric fire safety curtain assemblies specifically intended for protection of proscenium openings. For recognition as proscenium opening protection, the fire- and smoke-protective curtain assemblies would have to meet the requirements of NFPA 80 Chapter 20. Fire safety curtain assemblies for prosceniums are intended to provide at least 20 minutes of protection for audience members to safely evacuate the chamber.
Fire safety curtain assemblies for prosceniums are usually tested in accordance with ANSI/UL 263 or ASTM E119, as applicable to nonbearing walls and partitions for 30 minutes. Since fire safety curtain assemblies are only intended to provide a reasonable level of separation between the audience and an on-stage fire to allow safe evacuation of the audience, the only condition of acceptance from ANSI/UL 263 or ASTM E119 is to restrict the passage of flame or hot gases. Note the temperature rise condition of acceptance is exempted. Additionally, the upper two-thirds of the test specimen is exposed to a positive pressure between the furnace and surrounding area.
Smoke partitions
IBC Section 710.2 allows smoke partitions to be of the same materials permitted by the building type of construction. Section 710.3, “Fire-resistance Rating” specifies that, in and of themselves, smoke partitions need not have a fire-resistance-rating, but one may be necessitated by other requirements in the code. As such, fire- and smoke-protective curtain assemblies may be deemed compliant for use as smoke partitions. NFPA 101 considers smoke partitions similarly.
Horizontal assemblies (rated floor/ceiling assemblies)
IBC Table 601, “Fire-resistance Rating Requirements for Building Elements (Hours),” and Section 711.2.4 specify the fire-resistance rating of horizontal assemblies (floors and roofs). IBC Sections 703.2, “Fire-resistance Ratings,” and 703.3, “Fire-resistance Ratings and Fire Tests,” specify the primary method to determine the fire-resistance rating of building elements, components, or assemblies is based on the fire exposure and acceptance criteria outlined in ASTM E119 or UL 263. Although the hose stream requirements of these test standards are exempted for horizontal assemblies, relatively thin membranes cannot meet the unexposed surface temperature limitations and, as such, fire- and smoke-protective curtain assemblies cannot qualify as horizontal assemblies under these standards.
NFPA 101 Paragraph 8.3.3.4 and IBC Section 712.1.13.1, “Horizontal Fire Door Assemblies,” require fire door assemblies protecting openings in fire-resistance-rated horizontal assemblies to be tested in accordance with NFPA 288-2017, Standard Methods of Fire Tests of Horizontal Fire Door Assemblies Installed in Horizontal Fire Resistance-rated Assemblies, and achieve a fire-resistance rating notless than the assembly that is being penetrated. Fire- and smoke-protective curtain assemblies cannot meet the temperature limits on the unexposed surface. The hose stream test is not required for either floor/ceiling assemblies or the associated opening protectives.
When specific constraints are met, IBC Section 712.1.9, “Two-story Openings,” allows two floors to be interconnected. Horizontal sliding fire- and smoke-protective curtain assemblies that can automatically configure are available. Such horizontal applications would neither be subject to live or dead loads nor would they be in contact with combustible materials. As such, it may be considered reasonable to allow these assemblies (tested to restrict fire and smoke propagation for a minimum of two hours) to mitigate interconnection of levels and/or atrium requirements when installed at every other floor.
Additional considerations when determining suitability
Fire- and smoke-protective curtain assemblies automatically deploying either vertically or horizontally will be activated by a fire detection device or fusible link. When a fire alarm system configures these curtains, the activation signal is not allowed to be transferred through a building management system (BMS) unless the BMS is UUKL Listed in accordance with ANSI/UL 864-2014, Standard for Control Units and Accessories for Fire Alarm Systems.
With respect to “equivalent means of protection,” the relevant sections in NFPA 80 and NFPA 101 state the NFPA codes and standards are not intended to prevent the use of systems or methods equivalent (or superior) to the prescriptive requirements. It is the applicant’s responsibility to provide substantiation to the authority having jurisdiction, which is tasked with concurring the proposed approach is equivalent. When the material or method is approved as equivalent (providing the level of protection intended by the code or standard), it is recognized as compliant. IBC and IFC contain similar provisions.
