This article concludes the two-part summary of the 54-page Chapter 3, "Wood Construction," of the 667-page third edition of my book, Building Construction For The Fire Service . Part 1 of "The Building Is Your Enemy" was published in Firehouse® February 1996, part 2 in August 1996, part 3 in...
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There are many areas now where the majority of houses have wood-shingled roofs. In some areas, they are permitted wherever frame buildings are permitted. Fast fire department response, one-story buildings, wider spacing between buildings than in bygone years, and the fact that we have no extensive amount of shingled, closely spaced 2 1/2-story buildings such as existed 60 years ago have combined to keep the conflagration rate low. But given the coincidence of hot dry weather, brushfires that engage a large portion of available firefighting forces, high winds, and a hot fire in a wood-shingled structure, the threat of conflagration is still very great.
On the afternoon of July 31, 1979, the Houston City Council was considering an ordinance with minor restrictions on the use of wood shingles. The ordinance was tabled. The day was hot and dry. At about the same time, the fire department responded to an alarm for a fire at the Woodway Square Apartments. By that evening, 30 apartment buildings were destroyed, hundreds of people were left homeless, and an estimated $44 million in damage was incurred. The fire spread because of the wood-shingle roofs.
In wood-shingle areas prepare for a blitz attack to knock down the original fire quickly. Call additional units for downwind patrol immediately. Don't wait for confirmed reports of extension.
Row Frame Buildings
In older parts of many cities frame buildings were often erected in rows. These structures are contiguous and often have a common attic or cockloft, and may even have party walls which provide support to both buildings.
Rowhouses have a new life as townhouses.
Unless the units are divided by unpierced masonry fire walls, parapetted through the roof, the entire group should be considered as one fire building. The fire knows nothing of titles or mortgages.
Considering the group as one building may make the incident commander more likely to call immediately for the resources necessary to contain a large fire rather than thinking of the fire as one relatively small unit.
Wooden Cooling Towers
Cooling towers are used to disperse the heat from air-conditioning systems. When the tower is functioning, cascades of water pour down the inside. Despite this, much of the wood in the tower remains dry. If the tower is not operating, all the wood is dry. Electrical shortcircuits, fan-bearing friction or even birds carrying lighted cigarettes to their nests in the towers are few of the possible fire causes. Such a fire can be spectacular and disastrous. Embers from a tower atop a high-rise spread fire over a wide area.
Be aware of cooling towers in your area. Are they wood or non-combustible? Are they sprinklered? Don't be surprised by a huge wooden cooling tower recessed several stories below the roof line of a "fire-resistant" building. KNOW YOUR BUILDINGS!
Wooden buildings represent a major exposure hazard to nearby structures even sprinklered fire resistive buildings. The largest amount of resources ever devoted to a structural fire in the City of Los Angeles was for a three-story wooden apartment building that exposed a 14-story fire-resistive high-rise occupied by senior citizens. All floors of the exposure were involved on arrival. In addition, flying embers ignited 14 other serious fires.
Pre-fire plans should take such exposure problems into account. Units should be prepared to go to heavy-caliber streams immediately. Nothing is more ridiculous than videotapes showing a firefighter directing the piddling stream from a small line into an inferno. Drill on getting heavy-duty lines into action rapidly.
There is really no effective fire protection for large wooden (or wooden-interior) buildings, other than FULL automatic sprinkler protection, with all voids covered, an adequate water supply and proper maintenance.
A sprinkler system is like having the first-due engine company on the scene, in the building, with a charged line hitting the fire. Under this premise, fire departments should be much more proactive in the maintenance of sprinkler systems in service. Tight administrative systems should be in place to insure that the fire department is aware of sprinkler impairment. It is not just a matter between the owner and the insurance company or just a matter for the "Fire Prevention Division." Study Chapter 13, "Automatic Sprinklers."
Francis L. (Frank) Brannigan, SPFE, a Firehouse® contributing editor, is a 56- year veteran of all phases of the fire service. Thirty years ago he began concentrating on the hazards of buildings to firefighters. He is the acknowledged fire service resource in this area and his work has been credited with saving lives.