Standards and applications for smoke- and fire-protective curtains

The National Fire Protection Association (NFPA) 13-2016, Standard for the Installation of Sprinkler Systems, defines draft curtains as a continuous material protruding downward from a ceiling to create a reservoir for collecting smoke and heat.

Door latching requirements
IBC Section 716.5.9, “Door Closing,” and NFPA 101 Section 7.2.1, “Door Openings,” require fire doors to be latching and self- or automatic-closing. Unless otherwise permitted specifically, single fire doors and both leaves of pairs of side-hinged swinging fire doors require an active latch bolt to secure the door when closed. When the curtains are used as doors, they have to meet these requirements. It is a disadvantage since fire- and smoke-protective curtains may have difficulties in meeting these requirements.

Elevator lobbies
IBC Section 3006, “Elevator Lobbies and Hoistway Opening Protection,” requires shaft enclosures and elevator lobbies when the hoistway connects more than three stories. Elevator lobbies are required to be constructed as smoke partitions when sprinklers are installed throughout the building. Otherwise, elevator lobbies are required to be constructed as fire partitions. In either case, doors protecting openings in elevator lobbies are required for corridors. Other than hoistway doors and the elevator car door, Section 3002.6, “Prohibited Doors,” prohibits doors at the point of access to an elevator car unless such doors are readily openable from the car side without special knowledge or effort. NFPA 101 contains similar requirements where elevator lobbies are provided. American Society of Mechanical Engineers (ASME) A17.1/CSA B44-2013, Safety Code for Elevators and Escalators, Section 2.11.6.3 not only requires unrestricted egress from the elevator, but also limits obstructions preventing firefighters from visually observing the elevator landing/lobby.

IBC Section 3007.6, “Fire Service Access Elevator Lobby,” requires doorways to a fire service access elevator lobby to be a ¾-hour fire-door assembly. Section 3008.6, “Occupant Evacuation Elevator Lobby,” requires a ¾-hour fire-door assembly into occupant evacuation elevator lobbies. Such ¾-hour fire-door assemblies are required to pass the hose stream test. Fire- and smoke-protective curtain assemblies are not able to pass the hose stream test and, therefore, are not allowed for these applications.

Draft curtains
Paragraph 3.3.8, “Draft Curtain,” of NFPA 13-2016, Standard for the Installation of Sprinkler Systems, defines draft curtains as a continuous material protruding downward from the ceiling to create a reservoir for collecting smoke and heat. It references NFPA 204-2015, Standard for Smoke and Heat Venting, for additional information.

Paragraph 8.4.6.4.1 of NFPA 13 requires draft curtains where early-suppression, fast-response (ESFR) sprinkler systems are installed adjacent to systems with standard-response sprinklers. IFC Section 5106.3.2, “Automatic Sprinkler Protection,” requires draft curtains to separate ordinary and high-temperature ceiling sprinkler systems. For these applications, draft curtains are required to be of noncombustible construction. Depending on the structural base (e.g. a fabric of woven glass fibers), these products can qualify as noncombustible even with a combustible surface treatment.

NFPA 92, Standard for Smoke Control Systems, Paragraph 3.3.4, “Draft Curtain,” defines draft curtains as a fixed or automatically deployable barrier protruding downward from the ceiling to channel, contain, or prevent the migration of smoke. A draft curtain can be a solid, fixed obstruction or a deployable barrier descending to a fixed depth during its operation.

NFPA 92 Paragraph 5.5.2.3, “Balcony Spill Plumes,” recognizes draft curtains to restrict horizontal smoke migration. Paragraph 5.5.2.5 requires draft curtains to remain in place and confine smoke when the design fire is near the draft curtain exposing it to the maximum predicted temperature for the design interval time. Paragraph A.5.5.2.4 specifies draft curtains can be of any material meeting the performance criteria of Paragraph 7.2 of NFPA 204.

Paragraph 3.3.9 of NFPA 204 defines a draft curtain as a fixed or deployable barrier protruding downward from the ceiling to channel, contain, or prevent the migration of smoke. The performance criteria of NFPA 204 Paragraph 7.2.1 requires draft curtains to remain in place and confine smoke when the design fire is near the draft curtain exposing it to the maximum predicted temperature for the design interval time.

NFPA 101 Paragraph 8.6.9, “Convenience Openings,” allows escalator and moving walk openings to be protected as outlined in NFPA 13-2016, Standard for the Installation of Sprinkler Systems, when the building is protected throughout by automatic sprinklers. Depending on the occupancy, this option is limited to interconnecting no more than four contiguous stories.

The IFC (Section 1103.4.6, “Escalators Connecting Four or Fewer Stories”) and IBC (Section 712.1.3.1, “Opening Size”) allow escalator openings in Group B and M occupancies to be protected with draft curtains and closely spaced sprinklers. These same constraints also apply to exit access stairways and ramps, but are limited to four or fewer stories.

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