Reuse, Recycle, and Reassess
Why sprinkler protection for one kind of existing storage may not work for another
NFPA Journal®, September/October 2012
In these tough economic times, many companies are shying away from constructing new customized storage facilities and are scooping up empty warehouses for dimes on the dollar. In some cases, they aren’t even purchasing new space, but repurposing existing warehouse space to accommodate new products or new storage operations. The problem is that many of these owners do not understand that storage sprinkler protection is not one-size-fits-all.
This is especially true when looking at older buildings that use smaller K-factor sprinklers. Without the proper analysis of the existing system’s capabilities compared to the new hazards being presented, the result can be a significantly deficient system. In many instances, system deficiencies are caught during the permitting of the building as the new certificate of occupancy is being issued. Unfortunately, there are many cases where the authority having jurisdiction (AHJ) has not been trained on the new storage requirements, and the sprinkler protection scheme gets lost in the shuffle.
More common are the instances where the AHJ is never involved, and, as a consequence, there is no regulatory review of a change in storage hazard. This is typical when building owners change one or more of the criteria associated with the development of a sprinkler protection scheme for the storage hazard.
NFPA 25, Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, requires an owner to take the proper steps to confirm that the sprinkler system can handle the storage arrangements present whenever a change in hazard occurs. A review of the sprinkler system for effectiveness should be conducted wherever there is a change in one or more of the critical characteristics that drive sprinkler system design for storage areas. These changes include, but are not limited to, commodity classification change; change in storage height; change in clearance to ceiling; change in packaging, such as encapsulated to exposed; the addition of solid shelving; change in storage type, such as from shelf storage to rack storage; and change in pallet type.
Larger companies may have someone on staff to handle such analyses, but many smaller companies would need to contract with someone to conduct the analysis, if they were even aware that such action was necessary. Some owners believe it is the role of the AHJ or the inspector performing the NFPA 25 inspection to identify deficiencies in protection associated with storage commodities and arrangements, but NFPA 25 clearly defines this as an owner’s responsibility.
In some cases, the sprinkler system design might be appropriate for the commodity being stored and the storage arrangement being used, but changes in storage operation can limit system effectiveness. Optimizing rack loading is becoming more and more critical to many owners trying to maximize their warehouse volumes. In maximizing the efficiency of their rack loads, however, owners can unknowingly block flue spaces or, where in-rack sprinklers are used, create obstructions to the sprinkler spray pattern, compromising an otherwise properly designed system. In addition to large changes in which new product or new racking is used, it is important to understand that even small changes such as rack optimization can have a major impact on sprinkler system effectiveness.
Making the most of available storage space can be cost-effective, but failing to understand if the sprinkler system is properly designed when taking into account variables associated with stored goods can be costly.
Matt Klaus is a senior fire protection engineer at NFPA and staff liaison on NFPA 13, 13R, 13D.