“NEW YORK CITY PERMITS IT, AND THEY ARE TOUGH”
BY FRANCIS L. BRANNIGAN, SFPE
“New York City Permits It, and They Are Tough”: Update
This argument might be offered in an attempt to overcome your objections to combustible, truss-joisted multiple dwellings that are available as condominiums or rental properties. The complicated layouts of these dwellings make the structures hazardous to firefighters and occupants. Units within the structure may be one-floor or duplex (a unit occupies two floors). The advice to get on the floor below to determine the layout won`t necessarily work.
Recently the Third Battalion (East Bronx) of Fire Department of New York (FDNY) firefighters found fire showing from the front windows of a first-floor apartment. The front door, however, opened only to a stairway that led to the second floor. The entrance to the first-floor apartment was at the rear of the building. This could have been a very serious situation if a life were involved. A trussed floor partially collapsed.
The Third Battalion issued a notice that is very strong on firefighter safety. It warns firefighters to be aware of the collapse hazard, to limit the number of personnel in the building, and to go defensive when the fire situation so indicates. Firefighters must know these buildings.
More than 30 years ago, New York was concerned about the loss of life in “old law” tenements (prior to 1903) that had wooden stairways and were converted into rooming houses. Sprinklers were required in stairways, to hold the stairway while occupants escaped. They were somewhat successful in those simple layout buildings. The recent buildings with their complicated layouts were permitted to be built only with a stairway; the traditional New York fire escape was eliminated because sprinklers were in the stairway.
Some years ago, four Syracuse, New York, firefighters died in an old residence that had sprinklers only in the stairway and public halls. The effect of the sprinklers could not be determined.
In other jurisdictions, such buildings might be required to have a partial 13R sprinkler system, which covers most of the residential units but not the voids. The complicated interconnected voids in these buildings would make fighting a void fire difficult. Heat-sensing devices and penetrating nozzles might be useful. Opening up the voids admits oxygen to fire that may not be reached by hose streams.
Similar hazards may exist in large old houses that were converted to upscale “bed and breakfast inns.” These buildings have tons of dried kindling in the form of wood lath hidden behind the attractive decor. Charming but complicated layouts can make it difficult for guests to exit. (An excellent description of the problems of these old “lumberyards” is found in “Fire in a Queen Anne” by Bob Pressler, Fire Engineering, November 1998, p. 30).
A Great “Just in Time”: Update
District Chief Robert Winston of the Boston (MA) Fire Department responded to a burning three-story wooden building that was severely damaged by a gas explosion. He noted that firefighters were already in and around the structure. He immediately ordered an evacuation. A minute after the last firefighter left, the building totally collapsed, silently and with no warning.
Chief Winston recognized the hazard–a damaged gravity resistance system (GRS)–as a result of his study of Building Construction for the Fire Service. The entire story may be found on the Boston Fire Department Web page http//www.ci. boston.ma.us/bfd/home.html.
Ability Shows Early
Some years ago, a fire chief of a small city on the far outskirts of the Washington, D.C., commuting area had a strong opinion: “These people are our friends and neighbors. We don`t tear up their houses like the big city firefighters do.” A fire that fully involved a unit in a garden apartment occurred. A neighboring ladder company commanded by Jack McElfish, a young volunteer lieutenant, responded on automatic mutual aid. The lieutenant was a fire science student at Montgomery Community College and had learned how fire spreads through voids. He disregarded the chief`s dictum and went above the fire. He pulled out a refrigerator and found fire spreading upward through the wall voids. The chief changed his tactics. The lieutenant is now chief of the Richmond (VA) Fire Department and was recently elected president of the Southeastern Division of the International Association of Fire Chiefs. Congratulations!
High Strength Concrete (HSC): Update
When concrete construction was rediscovered in the last century, it was hailed as “fireproof.” Fire experience, however, has shown that concrete is subject to severe damage. Most concrete is merely noncombustible–it adds nothing to the fire load. Some concrete is formulated to meet fire resistance standards when codes require fire resistive construction. Note that fire resistance does not mean that the concrete will not be damaged. Concrete will spall (pieces break off from the surface when heated). Normal strength concrete (NSC) loses about 25 percent of its compressive strength at about 5757F and 75 percent of its strength at about 1,1007F (these are temperatures in the concrete, not ambient temperatures).
High strength concrete (HSC) permits the use of thinner structural members, an economic advantage. However, HSC loses much more strength than NSC in the same temperature ranges.
In addition, in the 5757F to 1,2007F range, HSC can spall explosively, breaking off big chunks. This causes a loss of compressive strength and exposes the tensile (erroneously called reinforcing) steel to failure levels of heat. The tendons of prestressed concrete are particularly vulnerable, since they totally lose their tensile strength at 8007F (cooler than a self-cleaning oven). This could cause a catastrophic collapse in a “good solid fire resistive concrete building” during firefighting operations.
A most severe case occurred in the fire in the Channel Tunnel, when a long stretch of the concrete totally failed. Fortunately, the tunnel at that point was in solid chalk. The National Institute of Standards and Technology (NIST), formerly the Bureau of Standards, has set up a project under the direction of Dr. Long Phan to study this very serious problem.
In the meantime, every fire department should learn from its building department the locations of structures containing HSC and insert this vital information and warnings about the hazards into the structure`s preplan.
When the Navy Firefighting School was built in Panama during World War II, no steel was available. A New York man, who had built with fire resistive concrete, constructed a 15-foot training pit with eight-inch concrete walls. In hundreds of fires, there was little spalling. A foam demonstration pit constructed by another builder spalled explosively and threw rocks at us during every fire.
“Fire-Rated Gypsum Board”
A common myth in the fire service is that nailing up some “fire-rated” gypsum board achieves fire resistance. The only “fire-rated” gypsum/wood structures are those that are identical to a structure tested at Underwriters Laboratory, or another recognized testing laboratory, in accordance with American Society for Testing and Materials (ASTM) E119. There is no such thing as a rated ceiling on triangular trusses as found in attics or where lowered ceilings in rehab jobs leave large voids above. (I have been told by Fire Engineering Technical Editor Glenn Corbett that some code-writing bodies have interpreted a gypsum-clad roof truss as meeting the requirement for “one-hour fire-rated construction.”) Very limited air space (and therefore less oxygen) is a feature of all assemblies that pass the test.
The ASTM E119 test, which provides our fire resistance ratings, is not at all adequate to ensure the safety of firefighters:
The test does not consider fire that burns down through the floor, enters the floor void laterally, or starts within the void–from a defective light fixture, for example.
The test fire temperature, developed in 1916, is not representative of the hotter, faster fires we have today.
The required test load of 30/40 psi static is not at all representative of the dynamic 450-pound load of two firefighters making a primary search.
A “rated wall” erected on a “rated floor” does not provide compartmentation. Fire can and has burned down into the floor and come up the other side of the wall.
Once the fire starts or extends behind the gypsum board, the board becomes a dangerous hindrance to the fire department.
If the extent of the fire in wood trusses is visible, firefighters can take a stand outside the collapse zone and hit the fire. A gypsum ceiling protects the trusses from hose streams and hides the extent of the fire. I can think of several fatalities that might not have occurred had firefighters been aware of the extent of the fire in the trusses.
Straw Houses: Update
In kindergarten, we learned from the story of the “Three Little Pigs” that brick is safe and straw is not. We already know that what appears to be a solid brick wall may in fact be a dangerous brick veneer wall.
Now, we have straw buildings. Straw bales stacked and covered with wire lath and stucco have been used to construct houses–very environmentally sound: They save lumber. The bales may be load-bearing or simply in-fill between the studs or posts of conventional wood structures. Without providing any specific information, the sympathetic article in the Washington Post (Sat., April 26 1997, E1, E10) states: “Tests show straw-bale structures actually hold up better than most conventional wood-frame structures in a fire.”
Characteristically, such structures have a “traditional truth window”–an area where the stucco is omitted to show the straw. This, of course, is the perfect entry point for fire to get into the straw. I would like to hear of any experiences you have had with such buildings.
About three-quarters of apartment dwellers have no fire or casualty insurance on their personal property. When a fire occurs, they are often left destitute and liable for payments on appliances that were destroyed. Many mistakenly believe that the loss is covered by the landlord. Others have the usual and statistically justifiable attitude that “it is unlikely to happen to me.” Perhaps a fire may not occur, but burglary is an ever-present threat, and both are included in renters insurance.
If your public education staff would mention this fact and make citizens aware of the availability of renters insurance, perhaps the percentage of those financially devastated by fire would be reduced. Information is available from the Insurance Information Institute at (800) 942-4242. Fire department personnel, of course, should avoid mentioning any specific providers. (Source: Washington Post, F1, 3/21/98)
Trauma Victims Can Hear
During World War II, “Loose lips sink ships” was the slogan to suppress careless conversation that could inform enemy spies. The fire service`s slogan should be “loose lips sink victims.” Even unconscious patients can hear careless remarks. In Fairfax County, Virginia, through the program “Rebuild,” recovered trauma victims help recent victims. An important lesson for firefighters and paramedics emerging from this program is that no matter how bad the situation is, all conversation within the victim`s hearing range should be positive. The victim should be encouraged and reassured.
The unbelievably offensive words “roast” and “crispy critters” should be expunged from the language–by department order, if necessary. Members of Rebuild speak to firefighter trainees at the Fairfax County training school. A whispered concern or a barked command might be business as usual for the rescue team, but either can create problems for the victims for years, as the victims recall the words they heard or thought they heard. Rescue personnel must be professional, which includes never forgetting that the victim is a patient and can remember every word heard. I just listened to a tape on which a firefighter is heard to say loudly, “This lady has a real bashed up head!” (Source: Washington Post, 3/23/98, p. B1)
Fire Bursting Out of Concealed Spaces
Concealed fire has been a booby trap for many firefighters. A seemingly routine opening of a wall or ceiling has admitted air to the smoldering fire with serious consequences. This hazard is increasing because of truss voids (truss lofts) and the creation of huge voids by dropping the ceilings of old high-ceiling structures during renovation.
Garden apartments, town houses, small office buildings, and small motels are among the types of buildings that generally are required to be of “protected combustible” construction. This means that the combustible structure is “protected” from ignition by a “sheath” of gypsum board and that floors and walls will meet fire resistance ratings. In 1971, the late Irwin Benjamin, then director of fire research at NBS (now NIST), asked me to look at garden apartment fires to try to determine why so many such fires extended beyond the area of origin, despite the “protected combustible” construction.
I discovered that the “sheath” was a fraud. It was full of pinholes, each potentially dangerous. What I learned from attending fires, studying ruins, and examining buildings under construction for 10 years was distilled and incorporated in Chapter 5 of BCFS3.
The defects are universal. In addition, the “sheath” concept does not include fires that start behind the gypsum board, which now are even more serious with truss voids (truss lofts) interconnected from floor to floor via pipe chases. Partial sprinkler systems that do not protect the voids are useless if the fire originates in or extends to the void.
In preplanning, look for the worst defects that can permit the spread of fire. Firewalls that are not parapeted through the roof fail because the plywood delaminates, rises up, and passes fire. Identify fire walls that do not penetrate combustible side walls. Often, handymen cut openings through attic fire barriers. Units must be assigned to defend these defective barriers early in the incident. If the fire passes one, you have a whole new fire. Maybe the initial fire will do more damage locally, but you will be ahead of the fire, not behind it playing catch-up. You didn`t build the defective building.
Work with the management and tenants to ensure an immediate alarm–no “don`t you call anybody until you check with me” instructions to employees. The tenants are often afraid of the authorities, and the management fears bad publicity. The manager should be convinced that a delayed alarm generates much more publicity than a quickly suppressed fire.
Deadlights are thick cylinders of glass set in metal or concrete frames on a sidewalk to give light to the under sidewalk vault.1 A pair of architects installed such a floor in an upper story of their house to light the dining room below. Is this equivalent in the gravity resistance system to the floor in a fire? The article relates that deadlights were used in the treads of staircases in the High Museum in Atlanta. Might such treads be the equivalent of unsupported marble steps that have collapsed without warning under firefighters? Perhaps somebody from Atlanta will write. n
1. The city owns the sidewalks and rents the space to the building owner. George Washington set the prices for Washington. Stories of the Triangle Shirtwaist Fire in New York City tell of bodies crashing through the deadlights.
n FRANCIS L. (FRANK) BRANNIGAN, SFPE, recipient of Fire Engineering`s first Lifetime Achievement Award, has devoted more than half of his 57-year career to the safety of firefighters in building fires. He is well known for his lectures and videotapes and as the author of Building Construction for the Fire Service, Third Edition, published by the National Fire Protection Association. Brannigan is an editorial advisory board member of Fire Engineering.