Identifying Lightweight Construction

By ROBERT MORAN

The State of New Jersey has been a leader in the exterior identification of truss-built structures for many years. This proactive approach to providing fire suppression units with first-due knowledge of the buildings they are operating in resulted from two tragic truss collapses that occurred in the state during the past 43 years.

The first occurred in 1968 at a bowling alley fire in Cliffside Park that killed five Ridgefield firefighters when a truss roof collapse pushed out an exterior wall, trapping the five members under the debris. The second collapse occurred in 1988 at a car dealership fire in Hackensack, which killed five Hackensack firefighters. At the Hackensack incident, the catastrophic truss roof collapse and resulting debris pile also buried and trapped the five members. New Jersey’s current system is excellent for identifying truss constructed buildings and enhances firefighter safety across the state.

Truss Roof Fire, Wyckoff, New Jersey

COLLAPSE AND FIRE EXTENSION IN WOOD-FRAME CONSTRUCTION

This truss symbol has been mandated in the state’s Uniform Fire Code since 1992¹ and requires placing a 12- × 6-inch reflective truss construction triangle-shaped emblem on the street side of all truss-built commercial structures and planned residential developments. In addition, three separate insignias must appear on the emblem indicating the exact location of the trusses within the structure: “F” indicates the floor, “R” indicates the roof, and “R/F” indicates both roof and floor. The individual buildings within a planned residential development are not required to display the emblem on each building as long as the emblem is visible at the entrances to the development area. Individual detached one- and two-family residences were exempt from the 1992 state fire code.

However, it is here where the program fails. By providing immunity to residential private dwellings, the system creates a significant and dangerous gap in its overall effectiveness by excluding our most common enemy. We are now entering an era of building construction in which contractors are using lightweight building components such as lightweight wood, preengineered lumber, and cold-formed steel to build new or renovate existing one- and two-family private dwellings. 

LIGHTWEIGHT TRUSS CONSTRUCTION TEST 

The increased use of truss construction components in our bread-and-butter fire buildings has led to increased firefighter deaths and injuries from the catastrophic collapse of fire-weakened floors and radically changed the interior environment within the most common structures in which we operate. Additionally, private dwellings built this way do not provide any significant identifiable exterior design or construction indicator on the exterior of the building that will help a firefighter recognize the use of these structural components prior to making entry. We are entering these dangerous buildings with no knowledge of the construction hazards within.

(1) Cold-formed steel framing in a private residential structure. (Photos 1 and 2 by Chris Radoian.)

A recent study designed to “enhance the understanding of hazards to firefighters posed by lightweight wood trusses and engineered lumber in residential structures” was conducted by Underwriters Laboratories (UL) with the Chicago (IL) Fire Department, the International Association of Fire Chiefs, and Michigan State University.² The study’s results confirmed that some of these types of structural elements can fail in as little as 6 minutes and 3 seconds under direct flame impingement. Most likely in the first critical moments, fire suppression crews would be initiating an interior attack on a fire over what would be a severely compromised working platform. 

ONE- AND TWO-FAMILY LIGHTWEIGHT CONSTRUCTION LOCAL ORDINANCE 

To reduce the dangers created by the escalating use of lightweight building components in residential structures and provide firefighters with immediate on-scene knowledge of their use within these buildings, the City of Englewood, New Jersey, adopted a local ordinance mandating the exterior identification of all new and renovated one- and two-family private dwellings constructed with truss and/or lightweight building components. This ordinance greatly enhances firefighter safety and operational effectiveness at fires occurring in these dwellings. Its adoption allows the Englewood (NJ) Fire Department (EFD) to identify and mark the use of lightweight construction in privately owned one- and two-family dwellings. The key safety factor to this identification system is that EFD members will be provided with critical preincident hazard information on the exterior of the most common and dangerous structures in which they operate. The identification for these type of residences, prior to the adoption of this local ordinance, was restricted by the state’s fire code.

(2) Cold-formed steel roof support system.

The ordinance, which was developed by members of the bureau of fire prevention with the chief’s office, mandates the placement of an identification insignia on the exterior of the structure to the left of the front entrance door on newly constructed and existing buildings identified as containing these types of building components. Additionally, the ordinance specifically identifies several methods such as plan reviews, site inspections, fire inspections, and fire department hazard assessments that inspectors and firefighters can use to identify these structures.

The local construction code office performs a critical role in the overall success of this program. Early and obvious identification of these lightweight components can be easily accomplished in the building plan review stage, which is typically completed by the construction official. Therefore, it is critical for the bureau of fire prevention and code enforcement office to maintain an open and supportive environment of effective communication through which they can distribute this information.

(3) Engineered lightweight wood floor support system in a private dwelling. (Photos 3 and 4 by John Lewis.)

In seeking out the most effective method of exterior building identification, the development committee decided to employ a triangle design that emulates the current insignia used throughout New Jersey. Adherence to a design that EFD members were already familiar with would be considered integral to the program’s overall success. In addition to the design, the committee believed that the current placement guidelines in the fire code requiring the installation of truss insignias on the structure’s street side would ensure that all firefighters entering the fire building could view the insignia and acknowledge the existence of lightweight wood components within the structure prior to making entry. In addition to the exterior identification, the structures would be made available on the EFD dispatch preplan system for instant identification on receipt of alarm.

One of the more interesting debates that surfaced during the program’s implementation involved the insignia’s proposed location and the possible detrimental effect it would have on the residence’s exterior aesthetic look. As with any local ordinance, the community and council members publicly discussed the program, requested information, and asked a variety of questions regarding any proposed ordinance. Fortunately, after working through numerous scenarios and questions during several council meetings, the EFD successfully adopted the proposal as written, thus creating a “win-win” situation for both the homeowner and the EFD. Additionally, in a concerted effort to promote buy-in by the property owner, all signs/insignias will be provided at no cost to the property owner.

(4) Close-up view of engineered lightweight wood “I” beams.

The fire prevention bureau will implement the program in direct association with the chief’s office and code enforcement personnel. However, the fire suppression division is also expected to assist with the identification of these structures through daily operational protocols such as hazard assessment inspections, district familiarization, and construction site inspections. An additional benefit of the ordinance is that the program encompasses both new and existing structures built prior to adoption. This was an important element to the program’s success; it allows the department to identify a vast number of older structures within the city that have been built using these construction methods over the past several years.

Using this team-oriented and proactive preincident approach to identifying these dangerous construction methods will allow the EFD to reach its goal of improving the life safety of all firefighters operating at incidents in the community. The program is a remarkably basic building identification system that can be easily developed and implemented by any fire department across the country. It is the EFD’s hope that others will follow and build on the foundation the EFD has set. 

ENDNOTES 

1. “Identifying emblems for structures with truss construction.” New Jersey Uniform Fire Code, 1996 Edition, Section: 2.20 Administration and Enforcement 5:70-2.20.

2. Backstrom, B. and Tabaddor, M, PhD. “Structural Stability of Engineered Lumber in Fire Conditions,” Underwriters Laboratories, 2009, Issue 3.

ROBERT MORAN, MA, CPM, CFO, is chief of the Brewster (MA) Fire Department. He recently retired after a 25-year career with the Englewood (NJ) Fire Department, where he served as chief of department from 1998-2011. Moran has also served as a member of the Bergen County (NJ) Arson Task Force, the Mid Bergen Hazardous Material Team, and the New Jersey Urban Search and Rescue Task Force 1 and as an instructor at the Bergen County Fire Academy. He is an adjunct instructor for Kean University and the New Jersey Division of Fire Safety and is a founding partner of “Jersey Guys” Fire Service Training, LLC.