How Safe is Safe?
May 1, 2010 12:00 PM, By Jeff Razwick
Actions schools and universities can take to increase fire protection.
Art Institute of Chicago classroom. Photo courtesy of Technical Glass Products
According to the U.S. Census Bureau, more than 130,000 elementary and secondary schools, and about 4,200 higher-education institutions operate across the country. These learning centers educate an estimated 75 million children and adults each year.
From a numbers standpoint alone, it is obvious that providing adequate fire- and life-safety protection is critical to the well-being of a multitude of students. Unfortunately, what should be a unified effort to increase the level of fire protection in schools and universities often causes dissension among facility managers, code writers and other building-industry professionals.
The debate centers on the issue of sprinkler systems and whether they provide sufficient protection against fire, or if specialty fire-resistant building materials also are needed.
A thorough fire-protection plan includes both. As part of active protection, sprinklers help slow or stop fires from spreading. Passive systems, or fire-resistant materials, provide around-the-clock, backup protection if sprinklers fail to perform. They also divide buildings into compartments to slow the spread of flames and smoke, enabling occupants extra time to escape. Incorporating one type of system without the other is short-changing safety.
A look at the benefits of each system, how they interact with each other and the importance of incorporating specialty fire-rated materials to meet the unique needs of education facilities helps demonstrate the value of providing a balanced fire-protection plan.
Sprinkler systems: alone are they adequate?
The benefits of sprinkler systems are undeniable. A report from the National Fire Protection Association (NFPA) states that when structure fires in schools (an average of 6,600 occur each year) are large enough to activate installed sprinklers, the systems were effective about 90 percent of the time. Furthermore, schools with sprinkler systems that experienced a fire cut the cost of property damage nearly in half compared with schools that didn't have sprinklers.
However, those statistics also mean that sprinklers do not perform one out of every 10 times. That amounts to about 600 school fires every year in which sprinkler systems may fail to perform. NFPA analyses break down the reasons that sprinklers fail to operate: The system is either shut off before the fire (63 percent); the system is not maintained properly (14 percent); it is not the appropriate system for the fire (11 percent); it is manually defeated (9 percent) or had damage to system components (3 percent).
Because sprinkler failure largely results from human error, advances in sprinklers likely will do little to help reduce their failure rate. Having complementary passive protection helps safeguard the lives of students and teachers.
An NFPA study of sprinklers emphasizes this need: “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.”
The case for complementary passive protection
When sprinklers fail to perform or water is not able to squelch flames, fire-rated materials such as gypsum, concrete, firestop sealants, fire dampers and fire-rated glass divide a building into contained spaces that can slow or stop fire and smoke from spreading to other parts of the building. As a result, occupants have more time to exit, and firefighters have more time to arrive before individuals and property are exposed to serious harm. Fire-resistive compartments also help prevent rapid spread of fire, which the NFPA has found to be a primary factor in numerous multiple-fatality fires.
Fire-rated materials help solve the challenges that come with using lightweight building materials. As designs have progressed, walls, floors and ceilings have become thinner. They burn more quickly than the stone and brick commonly used in the past. To provide adequate compartmentation, modern design requires the supplement of specialized materials with fire ratings.
One type of specialized fire-rated material is fire-rated glazing. Ordinary window glass cannot withstand the high temperatures generated from building fires. It also tends to shatter when heated, enabling flames and smoke to move quickly through interior spaces. Specialty fire-rated glazing materials now are available with a number of performance characteristics to improve compartmentation in areas where windows are required or desired to meet design goals.
Transparent sheets of ceramic-like glass can be produced to look like ordinary window glass and are available with fire ratings up to three hours, high-impact safety ratings and sound reduction. In addition, in critical fire-separation areas such as corridors and stairwells, glass firewalls can prevent the transfer of radiant and conductive heat. A fire can rage on one side of the glass, yet its other side remains cool to the touch. Glass firewalls also help improve visibility and security, and create open building designs.
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