SCHOOLS TRY TO KEEP FROM GETTING BURNED
- By Robbin Rittner-Heir
- June 1st, 2004
Flammability isn’t a desirable or acceptable attribute in any school building. This is particularly true when, on any given school day, there’s at least one disgruntled teenager in a high school somewhere who’s trying to express his or her displeasure with the system by setting fire to a school’s restroom.
Haven’t heard of any major school fires in this country? No, you haven’t missed anything. The fact is, the last notable fatal school fire was at Our Lady of the Angels in Chicago, back in 1958. According to historical data, that fire, which started in a refuse pile in the basement, claimed the lives of 92 children and three teachers, most of them trapped in second-floor classrooms. There were no fire detection devices, nor were the materials with which the school was constructed of a fire-suppressive design. There was a local fire alarm system, but, based on recorded information, it took about 13 minutes for the alarm to be sounded.
Much has changed during the last four decades, with the advent of greater fire safety instruction, fire drills, building inspections, fire-resistant building materials and construction methods. Stricter building and safety codes have prompted manufacturers to come up with products that have gone a long way toward saving lives and school property.
The U.S. Fire Administration reported in October 2001 that, according to findings by the National Fire Protection Association (NFPA) and the National Fire Incident Reporting System (NFIRS), 61 percent of all school structure fires and, specifically, 70 percent of all high school fires, are a result of arson. The report also states thatthe leading area of fire origin is the school lavatory.
Debra Miller, a consultant with Rolf Jensen & Associates , concurs thatthe greatest number of fires are started maliciously. The other major cause of school fires, she explains, are accidental fires resulting from poor design, poor installation or poor maintenance of whatever fire resistant materials or systems are being used.
The use of the term fire proof is something of a misnomer. Within the industry, Miller says, fire-proofing relates to materials applied to construction elements to make them fire resistant.
Building codes as they pertain to schools are covered by the NFPA and the International Building Code. While the two aren’t identical in content, Miller says, both require at least one of two things for schools to meet code: a one-hour fire-rated separation for every 20,000 sq. ft. of area, or automatic sprinkler protection throughout. Fire-rated construction constitutes passive fire resistance. This includes products such as flooring, ceilings, walls and doors that meet fire safety codes for slowing or resisting the spread of flames.
When you’re dealing with construction elements, it’s fire resistive, fire-rated(building) construction. It’s there, it’s solid, Miller says. There is, however, a caveat.
Automatic sprinkler protection allows for large open areas, without fire-rated separations, whereas blocking off every 20,000 sq. ft. with rated construction can limit design options, limit the amount of windows and create a somewhat more confining appearance, Miller says.
Some materials are natural choices for fire-resistant construction. Concrete doesn’t burn, making it an excellent and often-used construction material.
Though you might not expect it, many modern carpet designs also meet specifications for flame resistance, making it a desirable product for use in schools. In a burning building, carpet is not the problem, says Werner Braun, president of the Carpet and Rug Institute .
Ken McIntosh, senior director of technical information for the CRI, says that carpet will burn at the point of direct heat. Away from direct flame, it will self-extinguish.
Carpet fibers will not burn of their own volition, he explains.
Carpet must meet flammability criteria in two situations. The first is the Pill Test and the second is the Flooring Radiant Panel Test.
To pass the Pill Test, carpet can’t burn more than three inches beyond the point of ignition when a fire source is dropped on the carpet, such as a lighted match, with the source remaining lit for a period of two minutes. In tests using eight specimens of a type of carpet, seven out of eight specimens have to pass the test, or that product can’t be manufactured legally for sale.
The Flooring Radiant Panel tests the flammability of carpet when exposed to a fully developed fire that radiates heat onto the carpet being tested. If a fire is burning in a room, the carpet won’t propagate the flames, Braun says.
In case of fire, what’s above your head is as important as what is beneath your feet. If you’re required to put in a fire resistant ceiling, then you have to be concerned with everything above, says Robert Ganse, senior TechLine technical consultant for Armstrong Commercial Ceilings .
During a fire, it’s not uncommon for a ceiling grid system to expand and buckle, causing tiles to fall, creating an additional hazard. Armstrong’s Fire Guard systems are designed to maintain the integrity of the ceiling grid. Ganse also says that many of the ceiling panels used are a mineral fiber base, which are tested for flame spread and smoke development, which includes creation of toxic gases. Toxicity is not a problem, he says.
Classroom doors can be an important element for containing fire. In some cases, however, aesthetics may take precedence over materials providing the greatest fire protection.
According to Leon Yulkowski, president and co-owner of Total Door , a solid wood-core door has a 20-minute fire rating, while a steel door carries a 3-hour fire rating. Aesthetically, he comments, steel is not as appealing as wood, so architects tend to opt for wood doors.
The best compromise, Yulkowski says, is a steel door clad with a wood veneer. This, he says, gives the desired appearance, while maintaining the desired fire rating, as well as withstanding most types of abuse better than solid wood.
Exposed to flames, doors can bow and release from the door frame, therefore undermining the door’s seal and its ability to block smoke and fire, Yulkowski says. An intumescent coating, when applied to the steel, expands when exposed to heat, maintaining the integrity of the seal.
Another fire-resistant material is fiberglass, a component in the manufacture of the Whispertone Wallboard produced by Johns Manville . Erika Williams, business manager for the company’s acoustic insulation division, says their product is used in the manufacture of other end-use products, some of which can find their way into schools.
There isn’t a lot of new product development going on among the various manufacturers, Miller says. New product development usually is spurred by changes in fire codes. With current products meeting fire code requirements, there isn’t much incentive to find the next best thing.
Protection: Active or Passive
Another school of thought places less emphasis on passive fire protection, instead touting the greater benefits of active protection systems. Those are fire alarms, an automatic sprinkler system and, in rare cases, smoke control systems, Miller says.
Building codes mandate the installation of fire alarms. Since most injuries come from smoke-related inhalation, not the fire itself, immediate notification to evacuate the building is essential. Alarms include speakers and strobe lights, along with alarm transmission to local responders.
According to Miller, smoke control systems, which suppress smoke and flames, aren’t usually cost-effective for K-12 school environments. Those systems generally are used for protecting computer rooms housing essential data, archives and high-value electrical components, she says.
The issue of a sprinkler system vs. passive fire protection can raise heated debate among various professionals. Since most building codes make it an either/or decision, the method of fire protection chosen can boil down to money and aesthetics.
Yulkowski contends that the trend is moving toward eliminating passive fire resistance in favor of automatic sprinkler systems. He says that current codes allow for zero-rated fire resistant walls in exit corridors.
You can’t depend on sprinkler systems, Yulkowski says. He adds that the NFIRS reported in 1996 that, of the 5,189 total fires reviewed, there was a 39.7 percent failure rate of sprinkler systems in buildings that were equipped with them. Poor or no maintenance was at issue, he says.
Miller maintains that a sprinkler system is more effective for fire protection than using passive protection. A common issue at any school is the maintenance of the integrity of fire rated partitions, she says.
During initial construction and through the life of a building, cables, wiring and other utilities are often reconfigured and include routing through fire rated partitions, Miller says. Unless these opened areas are sealed with approved fire resistive material, the integrity of the fire resistive construction is compromised.
When properly installed, the sprinkler system can control a fire, so you don’t need a fire barrier. Miller says that, historically, building codes required corridors to have a one-hour fire rating. With an automatic sprinkler system, the corridors would not have to meet that rating.Although school boards, administrators and their architects are concerned about the provision of adequate fire and life safety, the typical school is designed simply to meet the local code requirements, she says.
Miller agrees that maintenance is vital, but says that schools would have to keep up with system maintenance to meet annual inspections by fire marshals. The key to successful fire protection and life safety measures is proper design, installation and maintenance of whatever systems are used.