BY FRANCIS L. BRANNIGAN,SFPE (FELLOW)
Editor’s note: For further reference, consult Building Construction for the Fire Service, Third Edition (BCFS3). Page numbers, where applicable, are included after the caption.
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This building is almost certainly balloon frame. Consider designating an “extension sector,” an officer whose function is to observe the building on all sides, watching for signs of fire spread such as blistered paint, smoke from the eaves, a sudden increase in the volume of smoke, and so on, below the operating forces or other signs that the building “built to burn” is succeeding and it is time to evacuate.
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Many solid masonry buildings have interior partitions that are continuous vertical voids like balloon frame. A quick way to check is to note the thickness of the walls at a doorway. Balloon-frame walls will be about as thick as today’s ordinary walls. Masonry walls will be about twice as thick.
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This is a platform frame building. One floor is built; the next floor is built on it. When under construction or demolition by a fire, the building is vulnerable to any lateral thrust such as wind, and collapse can occur.
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In this windstorm wreckage, there were few broken wood members. The structure fell apart at the nails. The importance of connections is stressed on pages 80-86 of BCFS3.
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This appears to be a brick building, but in the photo below we “undress the building” by pulling out a photo taken when it was under construction. We see that it is a platform frame building with a nonstructural brick veneer cladding, to deceive the viewer. The collapse of a masonry veneer wall is not a structural collapse, but the bricks are as heavy as structural bricks. A few of them can make your helmet frontpiece your belt buckle. As you look at a building, try to “undress” it in your mind’s eye and see the gravity resistance system.
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Additional information on the hazards of wood construction can be found in Chapter 3, pages 89-142, and Chapter 12 of BCFS3; updated in Ol’ Professor, Fire Engineering; and available at FireEngineering.com.
FRANCIS L. BRANNIGAN, SFPE (Fellow), the recipient of Fire Engineering’s first Lifetime Achievement Award, has devoted more than half of his 61-year career to the safety of firefighters in building fires. He is well known as the author of Building Construction for the Fire Service, Third Edition (National Fire Protection Association, 1992) and for his lectures and videotapes. Brannigan is an editorial advisory board member of Fire Engineering.
