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Fire Protection Engineering Essentials in NYC - NY Engineers

Written by Ankit Javeri | 1/24/18 3:00 PM

New York City is known for having some of the most demanding fire protection requirements in the world, and it would be possible to write entire books about the topic. Fire protection engineering firms must adhere to many standards when designing a new project, which include the NYC Fire Code, NYC Building Code and many standards from the National Fire Protection Association (NFPA). This article will provide a brief overview of the main specifications and building systems that NYC fire protection engineers must work with.

Although there is a large number of fire protection requirements, most of them can be classified into two broad categories:

  • Fire resistance features that improve a building’s ability to withstand fire and its side-effects. These features include fire walls and smoke barriers.
  • Fire protection systems that warn occupants or mitigate the effects of fire, such as alarms and automatic sprinklers.

Meeting fire protection requirements does not only improve safety for occupants, it is a prerequisite for legal use of a building in the first place! NYC authorities are very stringent when it comes to fire code compliance, but this can be expected considering the high concentration of tall buildings, as well as the large number of people inside them.

For many high-rise office buildings, a priority is to upgrade their fire protection systems to meet Local Law 26. The law was published in 2004 in response to the 9/11 incident, requiring large buildings to be fully equipped with fire sprinklers within 15 years (July 1, 2019). Unlike many other NYC laws that only affect new buildings and major renovations, LL26 imposes retroactive requirements that affect existing constructions. Since fire sprinkler installation can be time-consuming and disruptive in a large building, it is highly recommended that you evaluate the situation of your building as soon as possible.

Get a professional building inspection to find out if you meet Local Law 26

Making Buildings More Resistant to Fire

When a fire occurs, it is very important to contain both the flames and the resulting smoke. People avoid fire by instinct but tend to expose themselves to smoke, which is also lethal if a large amount is inhaled. Chapter 7 of the NYC Building Code details the fire resistance measures required, but first it is important to understand some key terms:

Fire Resistance Measure

Definition

Fire Barrier

Fire-resistant wall assembly that meets Section 707, where the fire resistance rating is continuous across its entire area.

Fire Partition

Fire-resistant vertical assembly that meets Section 709 and has protected openings.

Fire Wall

Fire-resistant and smoke-tight wall with protected openings, which extends from the foundation to the roof (or through the roof). It must have enough structural integrity to withstand the collapse of adjacent building elements during a fire.

Horizontal Assembly

Fire-resistant floor or roof assembly, where the fire resistance rating is continuous across its entire area.

Smoke Barrier

Vertical or horizontal membrane that meets Section 710 and is designed to restrict the movement of smoke. It can be part of a wall, floor or ceiling assembly.

Smoke Partition

Continuous and vertical assembly that meets Section 711, designed to restrict smoke but not necessarily fire-resistant.

The key concepts defined above are used throughout Chapter 7 when specifying fire resistance measures for NYC buildings. The chapter is over 100 pages long, but the main points covered can be summarized as follows:

  • Fire-resistance ratings and fire tests are required for construction materials in general.
  • Special fire-resistance ratings are required for structural components such as columns and trusses, due to their critical function in a building.
  • Special structural and fire resistance requirements are specified for exterior walls.
  • Fire walls, barriers and partitions are used to separate the building into independent areas, preventing or slowing the spread of fire if it occurs.
  • Use of fire-resistant shaft enclosures for staircases, elevators and other similar building elements.
  • Use of smoke barriers and partitions to smoke movement, preventing visibility or breathing limitations.
  • Use of horizontal assemblies with fire resistance ratings for floors and roofs.
  • Special requirements for electrical conduit, plumbing, air ducts or any other building system that crosses walls.
  • Fire resistance requirements for joints between walls, floors, ceilings or other assemblies.
  • Protective measures for openings in fire walls or partitions.

Together, these measures minimize the spread of fire and smoke in a building, providing more time for evacuation and for automatic fire extinguishing systems. In the case of a major fire that requires action from the NY Fire Department, fire-resistant constructions provide more time for the firetruck to arrive.

Active Fire Protection Systems

The previous section focused on construction features that make a building resistant to fire. Now will will discuss fire protection systems with an active response, such as alarms and sprinklers, which are covered by the NYC Building Code in Chapter 9. There are many types of fire protection systems that complement each other, and they are summarized in the following table:

Fire Protection System

Description

Automatic Fire Sprinklers

Devices connected to a piping system with a water supply. Individual sprinklers open in response to heat, showering the area below in a conical spray pattern.

Keep in mind there are alternative fire extinguishing systems that use substance other than water, such as carbon dioxide, foam or halon.

Standpipe

Piping that delivers water to connections used for fire-fighting purposes and located throughout a building.

Fire Alarm System

System that monitors the presence of fire and announces it upon detection, to take the necessary actions as soon as possible.

Emergency Alarm System

System that announces emergency situations in applications where hazardous materials are involved.

Smoke Control System

System that limits or redirects smoke movement, providing visibility and allowing breathing during evacuation. Passive smoke control systems use smoke barrier arrangements, while mechanical smoke control systems use fans to produce a pressure difference.

Fire Command Center

Location where the status of fire detection equipment, alarms and control systems is displayed, and where the manual controls for those systems are located.

Fire Pump

As implied by its name, a pump that is used exclusively for fire protection purposes.

Post-Fire Smoke Purge

A system designed to remove smoke from building interiors once a fire has been extinguished, in order to restore normal operations as soon as possible.

Auxiliary Radio Communication System (ARCS)

A wireless and bidirectional communication system used by Fire Department personnel, which is completely independent from the buildings electrical and communication systems.

Recommendations

NYC codes impose various fire resistance and fire protection requirements for buildings, and meeting them all is a significant engineering challenge. By working with qualified fire protection engineers, you can make sure your project is code-compliant and safe for its occupants. Through smart design choices, it is possible to optimize fire protection costs without compromising safety and performance.