By Warren G. Stocker | Fire Protection Engineering
From an owner's perspective, there is a
myriad of concerns relative to protecting a storage facility. The
expectation is that the fire protection engineer will aggressively
attack a design problem and come up with the right balance to adequately
address life safety and property protection. However, adequate and
least expensive should not be confused, although cost is obviously a
consideration. Herein lies the biggest challenge for the design
professional. How can one achieve the optimum design within the
parameters dictated by the owner; that meets applicable codes and
ordinances promulgated by the authorities having jurisdiction; and
satisfy one's moral, professional, and ethical obligations?
Alarms to warn occupants of fire are important components of life safety. NFPA 101 calls
for fire alarm systems in ordinary and high-hazard contents storage
occupancies that are not protected by an automatic sprinkler system and
whose total floor area exceeds 9,000 square meters (100,000 square
feet). However, alarms are not required in occupancies with low-hazard
contents. After reviewing the facts and making a determination that an
alarm system is needed, the next question is usually, "How many devices
are necessary to ensure they are audible and/or visible throughout the
building?" This represents one of the areas of frustration for the
owner. Codes rarely address all of the sitespecific conditions that
exist in a built environment. There is a natural tendency to apply the
general requirements, which in some cases may border on excess. For
example, is it practical to install horn strobes in every aisle between
10-meter (35 feet)-high double-row rack storage in a 12-meter (40
foot)-high building? At issue is the balance between minimum
requirements and enhanced reliability. Usually, there is an appeal for a
common-sense approach that will meet the intent rather than carry out
the exact letter of the code. This is where the design professional can
really have an impact by carefully evaluating the options and coming up
with a concept mutually acceptable to the stakeholders.
In addition to addressing life safety
issues, providing systems that will mitigate losses is one of the
primary objectives. Most codes require automatic sprinklers in storage
occupancies, particularly those with high-piled or high-hazard contents.
What is often stated is that codes provide the minimum requirements.
Typically, the design is based on the most severe hazard. With the
increased use of plastics in products and packaging materials, hazard
classification for mixed items can be difficult. This is further
complicated by the fact that the commodity mix in a storage occupancy
can often change. Determining the protection requirements for other
high-hazard commodities, such as aerosols and combustible/flammable
liquids, can be challenging as well. There is a delicate balance between
providing the right protection for the right hazard. Several years ago,
a fire occurred in a warehouse that contained Class III commodities for
decades. Over the years, combustible liquids in plastic containers were
introduced. A total loss resulted, primarily due to the fact that the
sprinkler protection had not been upgraded to handle the increased
hazard. This provides one of the best opportunities for the engineer to
excel by drawing on experience and utilizing resources, such as modeling
and available reference data stemming from actual fire tests, in
There is a delicate balance between providing the right protection for the right hazard.
Fire protection engineers not only have
to focus on effective protection in the design process, but they also
have to be cognizant of the needs of the facility owner beyond the
completion of the installation. There are operational issues to be
considered. The owner is looking for a trouble-free,
easy-to-maintain-system. If the applications involve a refrigerated
warehouse, frozen pipes are not uncommon. Although technology is
available to minimize premature actuation and research is underway to
develop more dependable systems, the fact remains this is a chronic and
costly problem for owners. The expectation is that design professionals
use their best judgment to evaluate new technology and the risks
associated with concepts with not much of a track record.
It may sound like owners/operators of
storage occupancies expect a lot from fire protection engineers. They
do! Fortunately, the profession has yielded a number of high-quality
engineers who are creative, dedicated, knowledgeable, and intuitive.
Fire protection engineers as a whole have met and often exceeded
expectations. Keep up the good work!
Warren Stocker is with Safeway, and is one of the SFPE's Vice Presidents.