COMMERCIAL STRUCTURE fires are a hazard that every fire department across the nation faces. Whether they’re small family-owned restaurants or large tilt-up distribution centers, commercial structures are increasing in size, construction design, and overall complexity. According to the National Fire Sprinkler Association (NFSA), in 2022 there were 522,500 structure fires, with 140,000, or 27%, occurring in nonresidential structures.
- The Complexities of Commanding the Commercial Fireground
- Training for the Commercial Fireground
- Critical Decisions at Commercial Building Fires
- Size-Up and Risk Benefit for Small Commercial Structures
Similarly, the NFSA reports that 95% of civilian deaths occur in residential structures; however, residential structures only account for 73% of the structure fires. Given this factor, the fire service must take a hard look at these buildings and implement effective tactics that take these statistics into account, including interior operations. To be effective in these buildings, we must understand what hazards exist and what changes have occurred both to our benefit and detriment as a fire service.
Understanding Construction
Traditionally, commercial structures were often thought of as either a Type I or Type II construction. As a review, Type I is Fire Resistive, with building materials andtechniques to minimize fire spread and maintain the structural integrity of the building. These buildings are commonly high-rise structures, multistory office buildings, and other large occupancies.
Type II is Non-Combustible, where materials and techniques are used to prevent ignition, burning, or contributing any structural components to fire spread. These are commonly found to be newer educational institutions, malls, and other low- to mid-rise structures. Contrary to common misconception, Type II can fail under fire conditions with direct heat or flame impingement on unprotected structural members such as steel beams and steel trusses (photo 1).
Ordinary construction is another type that is often found in use today. This is the style incorporating load-bearing masonry walls with wood structural roof and floor members.
Heavy Timber is not a commonly used construction type post-WWII; however, it is still in existence due to the building’s ability to withstand the test of time. These structures consist of six- to eight-inch-thick dimensional lumber. While structurally sound, they can require large volumes of water under fire conditions. The most common examples of Heavy Timber structures are cathedrals/churches and old mill industrial buildings.
Type V is the traditional wood frame. Often thought of as exclusive to the single-family home, this construction type has migrated into commercial construction. The use of engineered members and systems provides for easier building, as these engineered materials are true to length and square, making construction easier and faster.
While it would be great to just say these are the five building types, we are now seeing hybrid buildings. The podium construction is a common hybrid style, with residential building materials being placed on top of commercial/mercantile style buildings. The base floor is often a Type II building with a Type V on top (photo 2). The first floor is restaurants, shops, or small offices with apartments or condo living on top. These buildings offer challenges to the fire department, as the fire alarm systems are often separate between occupancies and suppression systems are unique to each occupancy and use type unlike traditional taxpayers.
In addition to the construction types, commercial occupancies have varying contents that challenge today’s fire service. The American fire service is designed and constructed for the single-family occupancy with a normal fire load. The commercial building, with a unique, high-intensity fire load, is an obstacle, to say the least. Palletized plastics, hazardous materials, and large quantities of fuels are just a few examples of the materials found in today’s commercial structures (photo 3). Add this to the fact that most commercial buildings are built for purpose and not pleasure (like a home) and there is not much open or unused space, and the fuel load is exponentially larger just by design. This must be considered prior to and while engaging in offensive fire operations on commercial buildings.
Another consideration is life hazard. Many times, these buildings do not have a life hazard other than the firefighters who enter the structure. We are not saying that you should stand outside and burn down the commercial building; we are saying take a hard look at risk-benefit and real-time tactical achievements prior to having your troops engage in that battle. History backed up with statistics have shown us that in commercial buildings, chances of victims are remarkably low, and we are more likely to kill or injure firefighters in commercial buildings (high risk/low benefit). Examples include the hard lessons learned from the Charleston Super Sofa Store fire that killednine firefighters, the Worchester cold storage warehouse fire that killed six firefighters, and the Hackensack Ford Fire that killed five firefighters. We are not saying that if someone is missing or trapped we don’t take measures to search all possible occupied spaces in the building, but we should take a real hard look at risk vs. benefit when it comes to commercial buildings.
Is the building sprinklered, and has the fire department begun supporting the fire suppression system for the building? Do you have adequate staffing to make an aggressive interior attack? Do you have a sustained or sufficient water supply? Is the building structurally sound and not going to collapse on interior crews? What are the building contents? As stated, these are not just bigger homes; these buildings vary in size, design, and layout. One contrasting example is the lack of exits or egress points of a commercial structure as compared to a single-family home.
Understanding Building Systems
So, how do we prepare and ensure that we have the best chance when we have a commercial structure fire? We need to understand building systems—suppression, fire alarm, ventilation, and standpipe systems. Sprinklers are the building’s first line of defense and provide a means to contain and control a fire. Sprinkler systems are designed and engineered to meet the building’s layout and contents. If contents change and the sprinklers are not updated to meet the new fuel load, a conflagration could result.
It is worth noting that not all commercial buildings have sprinkler systems. Installation and design are based on numerous factors that are spelled out in the fire codes (photo 4). That said, sprinklers do a phenomenal job at limiting fire loss and loss of life within a structure. They are the fastest means to get water onto a fire and MUST be supported by the fire department at the fire department connection at 150 pounds per square inch with a minimum of two 2V2-inch hoselines and a water supply (photo 5). We must change our mindset and recognize the sprinkler system as the first water on the fire. We must support that operation.
It is critical for firefighters to understand how the system works, how to support and supply the system, and when it is safe to shut the system down. The recommended timeline to shut the system down is 20 minutes after the fire is controlled. Just because the fire department has arrived, this is not a good indication to shut down the sprinklers. Prior to shutting down a sprinkler system, the fire should be in check, with handlines in place and risk of extension minimized.
Standpipes are another great building tool. They allow for remote connection within a building to provide for effective line placement and extinguishment. Crews must be trained on how to supply a standpipe system, limitations of the system, and how to connect and flow a hoseline. As with anything, if you don’t train and drill on it, you cannot count on it during a fire operation.
Air management is key. Recognize that air supply inside a commercial building is different than in a single-family home. Due to the size and complexity of commercial buildings, firefighters can find themselves in low-air emergencies. As stated earlier, exit options may not be as numerous as in a traditional single-family home. Unlike a residential structure with windows to provide escape routes, commercial buildings often offer few windows and exits. These building features inhibit firefighter self-survival in a commercial occupancy (photo 6).
Another building feature is ventilation. Many buildings have large ventilation fans that can assist with smoke removal or pressurization of a stairwell for evacuation. These systems can greatly assist firefighters and aid the survivability of potential fire victims. Again, it is of the utmost importance that the fire service understands fire systems and what effects ventilation will have on the systems. Firefighters must also place hands on and understand the systems within their local jurisdiction. The first time looking at a fire system should not be when the building is on fire.
Fireground Operations
The commercial structure fire still has the same basic fireground priorities, but they look different. The number of required firefighters, size of the building, fire load, and water supply are some of the biggest differences. National Fire Protection Association (NFPA) 1710, Organization and Deployment of Fire Suppression Operations, EMS, and Special Operations in Career Fire Departments, requires 28 to 43 firefighters for commercial buildings as opposed to 15 firefighters for residential structures. On single-family structures, we often bring enough water with us in terms of booster tanks. FSRI has proven that it often takes less than 300 gallons of water to extinguish a room and contents; with that, we often can rely on booster backups to ensure sufficient water for a single-family home.
Conversely, the commercial building fire requires a sustainable water supply through hydrant connections or tanker shuttles to ensure that both sustained and sufficient water is available to supply both the fire systems as well as the fire attack operation.
Water supply must be established prior to engaging in commercial building fire operations. Using the equation L x W 3 will give the required gallons per minute (gpm) needed for the size of the structure (photo 7).
When it comes to the actual fire attack, there are many factors to consider. Is there an active sprinkler system controlling the fire? Is there a water supply that will be able to sustain our interior operation? Are there enough crews on scene to sustain the operation? What is the building saying related to ongoing operations? If the fire is sprinkler controlled, the best line for attack may be the traditional 1V2-inch to 2-inch handline. The rationale is that the sprinkler system is controlling the fire with the “Big Water” that we often think of and need for commercial fire operations. We recognize that this is contrary to what many of us have been taught—“Big Fire, Big Water,” which is true. That said, sprinklers provide that, and our handlines are essentially mopping up and overhauling that controlled fire. We should match the line to the fire size and potential.
As it relates to fire attack, access is key. These structures are vastly different than a normal single-family home. Take the time to determine the best entry point for the best stretch to the fire and optimize crew efficiency and air supply.
As for nonsprinklered buildings, these will require “Big Water” from our lines and master streams. A 2V2-inch or larger line will be required to supply the necessary flow for fire control and extinguishment (photo 8). Given this flow rate, incident commanders (ICs) must consider the involvement of fire in the building-structural integrity-as fire affects the building’s structure and what life hazards exist beyond those of the firefighters. Again, we are not saying to stay outside and make a parking lot. What we are saying is to use a good risk-benefit analysis and have a strong strategic plan in place as the IC. When determining if placing a 2V2-inch line in the interior will have an impact, factor in true times for deployment and forecasting of where the fire will be in orientation and intensity once that line is in place.
Remember that a 2V2-inch hose weighs approximately 106 pounds per 50-foot section charged and provides a flow of 250 to 260 gpm with a l/s-inch tip. Do we have the personnel on scene to replace/rehab larger crews when the crews start running low on air or are unable to finish an assigned task? Do we have extra personnel on scene for a rapid intervention team (RIT), with enough RIT bags for a large number of crews? Is a second, third, or fourth alarm necessary to meet the needs of the expanding incident?
Ventilation is a tough task on these buildings. Depending on the size and layout, windows may or may not be afforded as options for ventilation. Vertical ventilation is a great option; however, depending on the roof construction and options, this might be a labor-intensive and time-consuming task. Consider the structural stability of the roof and presence of an attic space. We want to avoid bringing the fire into the void space of an attic if possible. Positive pressure can be an option, especially if the fire is contained in a space that can be accessed and is isolated from the rest of the structure. An example is a strip mall occupancy with no extension to adjacent exposures or an office space within a structure. If the space is large and open, our small truck fans will not work. They simply cannot provide enough power to move the air into the structure to provide the positive pressure. Truck- or trailer-mounted large positive-pressure ventilation fans will be needed and often are a regional request. Again, know your available resources, as they will often dictate what tactics can be implemented.
Search is still important in a commercial building. While it may take a lesser priority, depending on the structure and situation, a search should still be completed to ensure that no victims are present. (The building is considered occupied until we say it is not.) Obviously, if bystanders state that a life hazard exists in the building or the building lends itself to the presence of a life hazard, an aggressive search operation should be coordinated with the fire attack. Recognize that searches in these structures will be more complex and require more resources and time as well as staff to manage.
Also, provide instruction on search tactics and locations-for example, searching the fire floor, the floor above the fire, and the uppermost floor prior to searching below as those are the highest risks. Not only does this align the strategic and tactical levels, it improves accountability across the emergency scene. The assignment of “Primary Search” provides limited direction and very little accountability as compared to “Primary Search of the Fire Floor.”
As the IC, it is critical to remember not to task saturate a company. Recognize the potential a company has to perform, and assign enough resources to effectively and efficiently complete said task. This goes for all fireground functions but especially for search and rescue in a commercial occupancy.
Strong incident command is essential on these alarms. As we have described, commercial structure fires are labor intensive. It is important to get ahead of these incidents early with personnel and resources. Calling extra alarms early ensures that adequate staffing and resources are available. It is better to have a contingency plan and not need it than to have a task without a crew to complete it.
Also, specialty apparatus such as a mobile ventilation unit or an air cascade unit that may have a lengthy response are good to have built into your responses. This ensures that the right resources are coming when the IC has other challenges to address. Calling early in the incident will provide the resources on scene and available when needed. As the IC, you must be forecasting the incident and trying to be one step ahead of the needs of the crews, the incident, and the building.
One of the hardest decisions as an IC is when to deploy crews into the immediately dangerous to life or health environment (IDLH) and when to retreat crews from the IDLH. There are a lot of considerations before sending crews interior or transitioning from offensive to defensive mode. Red flags can often assist the IC in determining switching from offensive to defensive mode—for example, the type of building and how long has it been under fire conditions, the changing condition of the building, and opposing reports from exterior divisions and interior crews. Are the crews inside saying they are controlling the fire and conditions are not getting better or getting worse from the outside? Are there reports of flammable liquids reigniting behind crews, explosions, or running out of personnel for the required task? Red flags are good indicators for the IC to switch from offensive to defensive mode. An IC must have enough resources in place to handle any situation that may arise, especially a Mayday when in the offensive mode of operations!
Commercial structure fires are a challenge to the fire service. Every department has some form of a commercial structure and must be prepared, trained, and ready for when that occupancy is on fire. Through proper preplanning, training, and response planning, we can set ourselves up for success at our next commercial structure fire.
BRIAN ZAITZ is assistant chief of operations and training for the Kirkwood (MO) Fire Department. He is the safety officer for FEMA US&R Missouri Task Force 1. He is the president of the International Society of Fire Service Instructors, president of the St. Louis County Training Officers Association, Fire Service Advisory Board member for Detectogether, and commission member for the State of Missouri Fire Safety and Education Commission. He is a contributing author and advisory board member for Fire Engineering and a workshop instructor for FDIC and presented a 2023 Keynote at FDIC. He has a master of science in human resource development, is a graduate of the National Fire Academy’s Executive Fire Officer program, and has credentials as a chief fire officer and chief training officer.
MIKE MARTIN is a battalion chief for the Fenton (MO) Fire Protection District and is a 31-year veteran of the fire and emergency services. He has a bachelor’s degree in fire service business administration with an associate degree in fire science.
