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As seen in Life Safety Digest, Spring 2010

How much is a life worth?
Why fire-rated corridors are critical in educational occupancies

Each year, there are an average of 14,700 school fires across the U.S. requiring a fire department response. These fires result in approximately 100 injuries and $85 million in property damage, according to the U.S. Fire Administration (USFA). 6,300 of those fires (43 percent) are structural.

For years, a debate has raged over the appropriate level of fire protection in schools. There are two primary camps: those advocating fire sprinklers as a fully sufficient solution, and those calling for fire-rated corridors, either with or without sprinklers. From a life safety perspective, the best approach is for codes to require both sprinklers and fire-rated exit corridors in order to provide back-up protection in those incidences where sprinklers do not perform as required. This is especially true for schools, where the special needs of students require adequate time for safe evacuation.

Whether explicitly stated or not, the argument against a dual approach comes down to money. In a world of limited resources, it is clearly not monetarily feasible to make buildings perfectly safe. But where does the balance lie between costs and safety, and who decides?

Fire-rated exit corridors provide critical back-up protection for students when sprinklers do not perform as intended

Fire-rated exit corridors provide critical back-up protection for students when sprinklers do not perform as intended

Fire-rated glazing in exit corridors can improve daylight, visibility and fire and life safety

Fire-rated glazing in exit corridors can improve daylight, visibility and fire and life safety

Code Trade-offs: Solution or Problem?

Because sprinkler systems are expensive to install, the International Building Code (IBC) now allows schools to have exit corridors with no fire rating when sprinklers are in place.[1] The theory with the code trade-off is that shifting dollars from building compartmentation to sprinklers provides students and teachers effective and affordable protection against fire. But, this is short-changing safety given the fallibility of sprinklers.

Sprinklers save many lives and have played a major role in improving fire safety. It makes sense that they be required by code. But setting up sprinklers and fire-rated corridors as an either/or choice is a recipe for disaster.

Over the years, the National Fire Protection Association (NFPA) has conducted a number of studies of sprinkler performance and repeatedly emphasized that sprinklers should not be used in isolation. For example, one NFPA study states, “Even a well-maintained, complete, appropriate sprinkler system is not a magic wand. It requires the support of a well-considered, integrated design for all the other elements of the building’s fire protection.” Amplifying this point, another NFPA report concludes, “Sprinklers are considered to be one of the most important parts of life safety, but they are far from the only part. Adherence to code provisions for factors such as number of occupants, control of heat sources, flammability of furnishings, and availability and capacity of exits are essential” (emphasis added).

The reason for not relying on sprinklers alone is their approximate 10 percent failure rate.[2] Applying this figure to the 6,300 annual school structural fires statistic cited earlier could mean the possibility of 600 plus school fires each year in which sprinklers either do not operate when needed or are not effective in controlling fire. According to the NFPA, most of these failures (65 percent) are from the system being shut off before the fire, while other causes include turning sprinklers off prematurely (16 percent), lack of maintenance (11 percent), presence of the wrong type of system (5 percent), and damage to system components (3 percent).

Special Needs in Schools

While providing fire-rated corridors as supplemental protection to sprinklers is important in public facilities of various types, schools have several sets of conditions that make such corridors essential.

First is the nature of the primary users – students. In a fire, children may panic or not fully be aware of the most appropriate exits to take. Schools also typically operate with relatively small amounts of adult supervision, with student to teacher ratios of 20 to 1 or greater being common. As such, students need to be able to exit on their own, without teacher guidance. Further, since most schools now educate physically and intellectually challenged children in the same classes as others, the difficulties of a smooth and coordinated exit during fire are compounded. All of these factors argue for providing a protected egress that is fire-rated for an adequate amount of time.

Second, many school fires are deliberately set or are otherwise suspicious. USFA data show that these fires account for 25 percent of structure fires in kindergarten and elementary schools and 47 percent of fires in middle and high schools. Further, 55 percent of fires on school property occur between 8:00 a.m. and 5:00 p.m., the times students are most likely to be in school. The risk is relatively great that a large number of people will be in the building during a fire.

Third, as with other modern facilities, schools rely on lighter building materials than in years past. The building itself provides less inherent protection against the spread of fire, making the need for designated fire-rated corridors key.

Fourth, increased cabling for communications, computers and other equipment raises the potential for fire. Coupled with other causes of school fires such as arson and cooking accidents, the risk of fires will not necessarily decrease over time.

School lock-downs

Post-Columbine and post-9/11, school systems throughout the country have had to backtrack from fire drill procedures calling on students to immediately exit school buildings the moment a fire alarm is sounded. Out of growing concern that a fire will be deliberately set or a fire alarm falsely initiated in order to draw students out of their classrooms into the open where they are vulnerable to violent acts, schools have begun to institute “lockdowns” when fire alarms are sounded. These new lockdown procedures typically require students to be locked in their classrooms until authorities can sound an “all clear” after determining that no intruder is present in the school.

Such lockdown procedures increase significantly the length of time that students must remain in the school building before exiting. This, in turn, significantly increases the risks posed by fire. These risks can only properly be mitigated by requiring the redundancies of automatic sprinkler systems and one-hour fire-resistance rated corridors.

Benefit Versus Cost

School districts are notoriously short on adequate building funds, so there is a strong pressure to build cheaper. Yet, the decision to weigh relative levels of safety versus cost is usually not made at the local level. By providing a trade-off, the codes have essentially removed this as a point of discussion on school project funding.

Parents should be very concerned to know that schools frequently rely on one fire protective measure (sprinklers) without providing a passive back-up (fire-rated exit corridors) to protect their children while exiting the building in the event of fire. If the question of life safety benefit versus cost were posed to them, it is likely there would be an increased call for providing both types of measures.

Putting costs in perspective, it is also important to consider that schools typically are in service for 30 to 60 years. This provides a lengthy time to amortize the marginal costs of using both sprinklers and fire-rated corridors.

And, in the event local jurisdictions believe such complementary protection is not needed in their situation, it is appropriate that this issue be considered through a local building code variance, rather than it being automatically assumed at the national code level.

Current Code Change Proposals

The International Code Council (ICC) will be revisiting the issue of fire-rated school corridors during its 2009/2010 round of Final Action Hearings in Dallas this May. One of the submitted proposals (E113-09/10) calls for requiring one-hour fire-resistance rated corridors even when sprinklers are present. With modern multi-story school designs, this is important since more classrooms are either well above ground level, or underground, unlike schools from past decades where nearly every classroom had a door leading directly to the outside.

Conclusion

Although deaths from school fires are rare, the USFA reports that the injury rate is slightly higher than the average for all non-residential structures. There continues to be a high number of school fires, and the ramifications of sprinkler failure can be dire – without passive protection such as fire-rated corridors, fire can potentially spread unchecked through a building, or occupants can be trapped in spaces without adequate means of egress.

The building industry today has a wider range of fire-protective and fire-resistive materials than ever before, with multiple performance and cost options. In light of this, it is time to put aside code trade-offs and ensure that schools are adequately protected from fire.


Jeff Razwick is the president of Technical Glass Products (TGP), a supplier of fire-rated glass and framing systems, and specialty architectural glazing. He writes frequently about the design and specification of glazing for institutional and commercial buildings, and is a past chair of the Glass Association of North America's (GANA) Fire-Rated Glazing Council (FRGC). www.fireglass.com, (800) 426-0279

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References

  1. Chapter 9 of the International Building Code (IBC) only requires automatic sprinkler systems in schools with fire areas that are greater than 12,000 sq. ft. Unsprinklered schools with fire areas less than 12,000 sq. ft. must have one-hour fire-resistance rated corridors.
  2. See “The Latest NFPA Statistics on Sprinkler Performance,” by John R. Hall, Jr., NFPA Journal, March/April 2008 and “Reliability of Automatic Sprinkler Systems,” by William E. Koffel, PE, commissioned by the Alliance for Fire and Smoke Containment and Control, Inc., September 2005.

 

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