SPRINKLERS OUT OF SERVICE

BY FRANCIS L. BRANNINGAN, SFPE (Fellow)

Years ago while I with the Atomic Energy Commission, I required that a building in which the sprinklers were vital to occupants’ life safety be shut down if the sprinklers were turned off. No buildings were shut down, but the work was done at night. Auditors disturbed by overtime costs were satisfied when it was explained that programmatic and payroll costs would be greater if the project were shut down.

For the fire department, the legal authority is simple. If the sprinklers are turned off, the exits will not meet the Life Safety Code. Owners must understand the requirement for sprinkler work to be done when the building is closed, typically at night or on weekends. It is possible that political influence might be used to change this requirement. Probably the best weapon is to let it be known that the whole matter will be on the record and that, if a disaster should occur, all concerned will be faced with huge personal lawsuits for liability and possibly criminal charges. Life safety sprinkler protection must be operable 24/7/365.

FIREFIGHTER SAFETY: UPDATE

When the Omega Sprinkler fiasco hit the public press, a firefighter was quoted to the effect that it made no difference to firefighters if the sprinklers were ineffective since firefighters would fight fires the same old way. In a letter to the editor of the National Fire Protection Association’s NFPA Journal (Jan/Feb 2002), Deputy Chief Carl Maurice of Fairfax County, Virginia, expanded my horizon from occupant concern to firefighter safety by effectively pointing out that a building built as a sprinklered building was planned for a fire to be fought and contained by sprinklers. The general concept is that firefighters should be required only for supplementing the sprinklers.

(1) This parallel chord truss is made of heavy lumber held together by metal connectors. It would probably last longer in a fire than the familiar lightweight trusses, but failure of a single connection could cause the truss to fail.

He correctly pointed out that many valuable code relaxations were provided to the builder in return for installing sprinklers. Travel distance to exits is increased, making them farther apart and sometimes fewer in number. Flame spread characteristics of finish may be higher. Fire areas may be greater than normal. Protective insulation of steel (usually but incorrectly called “fireproofing”) may be reduced or eliminated.

It would be well to check with the building department to determine the differences between a similar sprinklered and unsprinklered building of the same type in your area and determine how those differences affect firefighter safety and how your tactics should be adjusted.¹

FINGER JOINT TRUSSES: UPDATE

Jerry Knapp of the Rockland County (NY) Fire Training School and Captain Rick Strauss of the Lake Mohegan (NY) Fire District had learned that finger joint trusses were being used in house construction in their area. Such trusses do not have metal gusset plates but a series of long points cut into the end of each piece. The pieces are then glued together (see Building Construction for the Fire Service, Third Edition, p.117 for failure of finger joint trusses in normal use). The department was well aware of the truss hazard but wanted to know whether these trusses fail sooner or later than gusset plate trusses.

(2) Note how tensile loads are transferred from truss to truss by light steel rods. Heat would cause these trusses to elongate and thus fail in their tensile function, or the ends might burn out of the wood. They are necessary, or they would not be there. The failure of any necessary structural component should be a red flag to firefighters. We must operate from the point of view that all structural elements are necessary or they would not be in place. (Photos by John Brannigan.)

My answer was “a truss is a truss is a truss.” No firefighters should be on or under any burning trusses. Failure is unpredictable, no matter what the connections.

DANGEROUS HEAVIER TRUSSES: UPDATE

(3) Bearing wall panels consisting of oriented strand board (a.k.a. chipboard) panels enclosing several inches of foamed plastic. Even if the plastic is chemically inhibited to control ignition, the plastic will “lose dimensional stability”-that is, melt-thus making it unable to continue carrying the load; collapse would be probable. [Photo courtesy of Assistant Chief Kan Hanks and Captain Jim Traski, Naugatuck (CT) Fire Department.]

A new truss hazard has appeared. The wooden members are at least four inches thick. This heavy wood might deceive firefighters with regard to the stability of the assembly. The connections are flat steel plates screwed into the wood. The tension members are light steel rods with turnbuckles running from truss to truss. We would have no idea of when one or more of the metal connections might fail and cause the truss to fail. The failure might well be progressive.

DOME TENSION CABLES: UPDATE

(4) A domed structure in Wilmette, Illinois. The dome, like all domes, wants to kick out at the base.

A dome can be described as an arch rotated around an axis. Like the arch, the dome wants to kick out. This problem can be controlled in one of three ways:

• A mass of masonry at the base.
• Steel connectors tying the bases of the arches together. Look for this hazard in churches and other structures with wood arches that are not buttressed by stone. If the church is built on a concrete slab, the tie rods will be buried in the concrete. If there is a basement, the tie rods will be in the basement ceiling totally vulnerable to a basement fire. If the rods fail, there is nothing to prevent the arches from kicking out.
• Michelangelo used iron chains to hold together the dome of St. Peter’s Basilica in Rome.

RUBBER “SLATE “SHINGLES

An article reported that rubber tires are being reclaimed to make imitation slate shingles. I would like to hear of any such installation.

(5) It is held together by steel cables. “Fireproofing” (better word is insulation) was applied to the cables. The effect of a severe fire on such “fireproofing” is open to question. (Photos courtesy of David White, publisher, Industrial Fire World.)

THE BUILDING IS YOUR ENEMY. KNOW YOUR ENEMY.

A personal note: In my presentation at FDIC 2002, a slip of the tongue caused me to say I was going home to celebrate our 50th wedding anniversary. My wife Maurine, watching the monitor in the Green Room, was shocked. As I well knew, we were married 58 years ago when we were both Naval officers.

Endnote

1. For more on this subject, see “Update: Preplanning the Big Box Store,” Ol’ Professor, Fire Engineering, Nov. 1999, and “A $280 Million ‘State of the Art’ Sprinkler Disaster,” Ol’ Professor, Fire Engineering, Oct. 1997.

FRANCIS L. BRANNIGAN, SFPE (Fellow), recipient of Fire Engineering’s first Lifetime Achievement Award, has devoted more than half of his 59-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 (National Fire Protection Association, 1992). Brannigan is an editorial advisory board members of Fire Engineering.

WOOD AND PLASTIC STRUCTURAL SANDWICH: UPDATE (3) Bearing wall panels consisting of oriented strand board (a.k.a. chipboard) panels enclosing several inches of foamed plastic. Even if the plastic is chemically inhibited to control ignition, the plastic will “lose dimensional stability”-that is, melt-thus making it unable to continue carrying the load; collapse would be probable. [Photo courtesy of Assistant Chief Kan Hanks and Captain Jim Traski, Naugatuck (CT) Fire Department.]