Not All Fire Sprinkler Systems Are Created Equal and Why It Matters

The provisions and requirements for fire sprinkler systems within buildings have been mandated within codes and standards since the late 1800s. The inclusion of these systems fit within our core principles of life safety, incident stabilization and property conservation.

The intent of fire sprinkler systems within commercial occupancies is first to ensure the safety of occupants and to allow them to egress. These systems buy time by addressing a fire during its incipient stage and by providing a longer tenable environment for occupants. That said, they also ensure that the building is preserved and that property damage is lessened.

Fire sprinklers also allow firefighters time to address incident stabilization while the fire suppression works, which gives members time to address the incident as a whole.

Most new buildings contain these systems, and the fire service has grown accustomed to working with these systems. Further, they are becoming more common in all constructions. However, not all fire sprinkler systems are created equal, and it does matter.

Sprinkler system and occupancy classification

When a building still is in its conceptual design phase, even well before architectural drawings are drafted, it’s designated with an occupancy classification. This occupancy classification is essentially the primary purpose and use for that building. From there, an assessment of types of commodities—what will go into the building—and what level of hazards those commodities entail is characterized. This is where provision for the fire sprinkler system begins. Requirements are dictated based on the building’s use and type of materials and commodities therein.

A fire sprinkler system is broadly calculated (hydraulically) to provide an adequate amount of water for the hazards that are present, which also is driven based on occupancy classification. Similar to the hierarchy of occupancy classification, there are varying levels of sprinkler density requirements—meaning a greater quantity of water per area might be needed when the hazard level increases.

Sprinkler density is the amount of water that’s discharged by the system, per unit area, with greater hazard areas or different commodities necessitating greater water demand. Here is where this becomes important for the fire service: Just because a fire sprinkler system is present doesn’t mean that it’s appropriate for the hazard level that’s present, particularly when the building changed occupants, processes, levels of activity or quantities of commodities of goods that are within. With aging infrastructure, urban renewal and the swapping of tenants into buildings throughout the years, it’s possible that, although present, a fire sprinkler system might not adequately address the hazards of the new occupant or its processes unless the system was assessed appropriately through an engineering analysis.

Changed hazards

The engineering analysis is important for the fire service to address during pre-incident planning. A fire sprinkler system that isn’t calculated hydraulically with the appropriate sprinkler density for what’s present within the building might not address hazards effectively, thus presenting a problem for responding crews.

It’s likely with aging infrastructure that a building or facility might have changed ownership over the years or changed processes or that the level of activity within the building changed. This is common in all jurisdictions. America’s buildings are aging, and within them, their fire suppression systems are, too.

With these changes, the building’s occupancy classification must match the primary use of that building. Accordingly, the fire sprinkler systems that are installed must be designed to handle those hazards.

The occupancy classification should come first. This is a formal process and usually is handled by the building department. Whenever a building’s use changes, the occupancy classification should be assessed to see whether it still is relevant. If it isn’t, it should be changed formally, with a new certificate of occupancy issued that matches the new primary use of the building. From there, all other requirements, including the fire sprinkler system, the fire alarm system and even fire department access requirements, can be addressed.

Pre-incident planning

Once a building’s level of hazard is assessed, the fire sprinkler system can be calculated for the appropriate density per area, based on the anticipated commodities.

The company officer who conducts pre-incident planning should know the occupancy classification of a building as well as what the fire sprinkler system is designed to do. These should match. If they don’t, the question should be asked whether the fire suppression system will address the hazards within. For example, any hazardous materials occupancy likely shouldn’t have a light hazard sprinkler density rating. Such a rating usually is reserved for what we would consider light hazard occupancies, such as office buildings.

Knowing the occupancy classification and what the fire sprinkler system is designed to handle are important concepts to catalog, because they might affect strategic and tactical considerations for that occupancy significantly.

Although fire sprinkler systems can be highly effective at ensuring life safety and property conservation, they only are as good as they are designed. A system that’s designed lower than the hazard level that’s present won’t perform as intended and will affect operational strategies negatively.

A duty to know

As fire sprinkler systems become more prevalent and as our infrastructure continues to age, it’s important that the minimum life-safety systems are present and that they are capable of addressing the level of hazards, even if the hazards change, as most processes do throughout the decades.

Pre-incident planning should include the review of occupancy classification as well as the fire suppression system. Both are core fundamental concepts to assess whether the building will perform as intended in the event of a fire.

Fire sprinkler systems, although highly effective in reducing injuries, fatalities and property damage, are not all created equal. The fire service has a duty to know how hazards within a building can affect the design and engineering of that system and its effectiveness.