A shopping-season look at pre-fire planning for mercantile occupancies
NFPA Journal, January/February 2011
NFPA 101®, Life Safety Code®, defines a mercantile occupancy as one used for the display and sale of merchandise. Mercantile occupancies vary in size from small, stand-alone stores to enormous multilevel, enclosed shopping malls. Regardless of size or design, pre-incident planning is crucial for protecting these spaces in the event of fire.
The threat to life in a mercantile occupancy can vary dramatically. Compare the potential life-safety problem during business hours, especially during the Christmas season, to times when the store is closed for business. In the first instance, there could be thousands of people in a store or mall who are unfamiliar with the layout and location of alternative exits. During non-operating hours, only a few employees or security people would normally occupy the property.
The large fuel load associated with mercantile occupancies, combined with a large, undivided area, can present a significant extinguishment challenge. The fuel load, arrangement of store displays, and large undivided areas may make it impossible to control an advanced fire in large stores. However, this does not automatically translate into a defensive attack. For example, 52 percent of reported structure fires in department stores that are occupied and operating are confined to object of origin, 62 percent if sprinklers are present. However, even the most complete and effective fire safety design will not eliminate the possibility of a large fire. Therefore, contingency plans should be made.
Newer stores are more likely to be built with lightweight construction, but they are also more likely to be sprinklered. Large fires are thus less likely to occur but more likely if they do occur to present potential hazards for firefighters entering the building to initiate an offensive attack. For example, suspended ceilings can hide a large volume of fire that can weaken the roof or ceiling structure, and large, open areas are particularly vulnerable to catastrophic collapse when exposed to high heat levels. If confronted with a well-involved fire in this kind of building, evacuate occupants and move to a defensive operation.
Strip malls and older shopping centers are usually separated by fire walls that slow fire extension. The strip mall layout generally provides egress and access from the front and rear of each business.
Enclosed shopping malls tend to be much larger and more complex than strip malls. Some large, enclosed malls cover several blocks and contain entertainment venues, hotels, and other occupancies in addition to retail stores. Merchant kiosks may also be located in pedestrian areas, as may seasonal displays of cars, boats, and RVs. It is virtually impossible to locate smaller stores in huge malls without a map or directions from mall personnel.
Our recommendation is on-board, computerized pre-incident plans with a search engine that can provide primary and alternate directions to specific stores or areas in the mall. Often, the degree of enclosure between stores in an enclosed mall is not complete. Typically, stores are open to the enclosed mall walkways from the front, with metal grating lowered during non-store hours. Fortunately, these malls are usually protected by sprinkler and smoke-control systems.
The latest trend in shopping is "lifestyle centers," which are laid out as multiple blocks of stores in a shopping complex, much like a city street. Like strip malls, most stores in a lifestyle center complex can be accessed directly from the outside. Most codes require stores in lifestyle malls to be sprinklered.
Pre-incident planning is essential to fire departments responding to large mercantile buildings or groups of buildings. Because of the fairly regular turnover of tenants in shopping centers of all types, regularly updating pre-incident plans is crucial.
This column is adapted from the author's book StructuralFireFighting, available online or (800) 344-3555.