More Dangerous Myths
FIRE SAFETY
Don’t believe everything you hear or read— not when there are lives at stake.
Know where the other person is coming from” is one of today’s popular catch phrases. It’s equally important to know the mental baggage he or she is carrying.
I have often been amazed at the beliefs underlying executive opposition to fire protection recommendations. At times it takes real digging to get them out in the open. It can take skilled diplomacy to excise the myth without doing serious damage to your ongoing relationship with the person.
I had been tipped off that a Navy captain was making a trip from Washington to Norfolk to chastise me for lowering the fire protection level of a hospital with only ambulatory patients, because he believed that “ambulatory” meant that they had to be carried off in ambulances. It would have been fatal to spring the dictionary on him. I got out the report and talked about the hospital situation at great length until he sensed that he had made an error, and without a word we slipped over to another matter.
Concrete is fireproof.
When concrete was first developed, it was hailed as the answer to most fire problems because it was “fireproof.” The word “fireproof” has been generally discarded, though “fireproofing” is still used to describe the system used to insulate steel from the heat of the fire. “Fire-resistive” is properly applied to floor assemblies or columns built the same as units which have passed the ASTM El 19 Fire Endurance test, which provides ratings in hours.
Concrete is inherently “noncombustible.” It may be formulated to be “fire-resistive” if desired or required. Noncombustibility cannot be uncritically accepted as a desirable fire characteristic.
Consider typical concrete teebeams in a one-story warehouse. The building is code-classified as “noncombustible.” Fire can cause the concrete to spall off the bottom of the beam, exposing the tendons which provide the tensile strength. The tendons lose their tensile strength at 800° F.
Reinforced concrete is a “composite material.” It’s composed of two elements: steel, which provides the tensile strength, and concrete, which provides the compressive strength. The two elements must stay in intimate contact to react together under the load. This contact is lost when the steel tendons slack off. There is no longer a structural element. The concrete may fail of its own weight or under a load. Falling concrete or failed floors or roofs may cause serious injury to firefighters.
Even concrete buildings rated “fire-resistive” must be regarded with suspicion. The supposedly fire-resistive concrete may not have been formulated properly. Metal expansion joints may transmit fire by conduction or, in the case of aluminum, by molten metal. Utility penetrations through floors may permit extension. When precast wall panels are used, perimeter firestopping may be ineffective or even nonexistent. Heavy concrete structures have literally been eaten up by long, sustained fires in high fire loads.
An “OK” by the fire inspector means “no problems“.. .or does it?
Shortly after the disastrous Our Lady of Angels School fire, the principal of our local school proudly announced that only one violation had been noted by the fire marshal: a cracked glass in the frame of the permitted occupancy notice! In fact, the school was a death trap, loaded with low-density, combustible fiberboard, and the stairways were wide open.
The fire marshal’s legalistic answer to my furious attack was, “We can only report items that are code violations.” He didn’t care for my suggestion that the reports should be flagged, “Reliance on this report may be hazardous to life, limb, and your financial wellbeing.”
No doubt, my hot-headed suggestion was not the best, but seriously, we would like to hear from fire departments about how they handle the situation when serious fire hazards aren’t in violation of the local code.
The safety of occupants is related to the length of fire department ladders.
In the TV reporting of every high-rise fire, it’s obligatory for the reporter to note that the fire ladders were “too short.” A trip down a 100-foot aerial ladder is a real thrill for a citizen —imagine a 1,000-foot ladder.
This myth has been the basis of many codes. After the disastrous Triangle Shirt Waist Fire in 1911, legislation was passed requiring sprinkler protection in factories of six or more stories in height. The assumption was that below six stories there was no problem because fire department ladders would be adequate for escape. The Monarch Undergarment fire of 1951, in which over 50 died in a building of less than six stories in height, proved the inadequacy of the law.
Prior to 1970, the United States government was building some of the worst possible high-rise buildings. A fire occurred in the Cleveland Federal Building, partially occupied and still under construction, which graphically demonstrated the General Services Administration’s life-hazardous building practices.
The director of GSA called for a reversal of its policy, specifically to build the best rather than the worst buildings. A conference of experts was convened in Warrenton, Virginia in 1971, during which the high-rise building was defined as one beyond the reach of ground equipment. True enough, but this perpetuated the six-story myth. Typically, shortly thereafter a state legislator proposed that all floors above the sixth be required to be sprinklered.
The key life-safety question in all buildings is how long it takes occupants to reach a place where they are safe from the killing products of combustion. Since, in many situations, it’s manifestly impossible for the occupants to escape the fire in time, the solution is to eliminate or reduce the products of combustion by suppressing the combustion. The secret of suppressing combustion is to “put the wet stuff on the red stuff.” By far the best way to accomplish this is with automatic sprinklers throughout the building.
