The following are some indicators to watch for and or consider that give some indicators of collapse.
Review them your self, and pass them along for a discussion among the troops.
It certainly is not all inclusive, but it is easily remembered because it spells the word COLLAPSE.
Construction of the building – Know the five types of building construction as defined by NFPA 220. Know that certain buildings, wood frame certainly, will fail quite readily under fire conditions. The mini-mart store of cinderblock with a bar joist roof will certainly fail pretty early under high fire conditions. Look around your response district.
Occupancy Loading – Does the building have contents such as paper, fabric etc., that will absorb firefighting water and add weight to the already damaged structure.
Lightweight building materials – We covered this one pretty good last week, but the bottom line is this one. While we understand that mass of the building unit adds greater weight, a larger mass will take longer to deteriorate ( IN MOST CASES, BUT NOT ALL) then a structural member that has less mass.
Length of burning time – No one person knows the answer to when a building will fail, but common sense tells us that the longer it is attacked by fire the sooner we can expect failure. How long has it been burning prior to your arrival, and how long since you have been here. This is another great use for the 15 minute status report.
Ankle deep water or accumulating water – No mystery to this one at all, water weighs 8.34 pounds per gallon, we add it to the building in 100 gallon increments. If it is not running off and just standing, let the building drain properly before completing overhaul activities.
Parallel Chord truss beams – Any team we see this type of beam, whether steel or wood, it should raise some degree of concern. Again I am not talking about the larger member chords, but certainly any lightweight beams of this type.
Special Matter – Look around your community for the telltale signs that a building may already being braced and supported from falling, without a fire inside. Corner angle braces on buildings, old fashion star supports, additional temporary columns in place are all indicators of building weakness.
Exposed steel – Again we have heard about this forever. Exposed steel will begin to lose strength when exposed to about 800 degrees. When you are doing a pre-fire inspection or survey and you see the steel beams over your head, think about that under fire conditions.
Just a couple of quick points to enhance firefighter safety and make you think. Easy to remember because each point spells the word….
Stay Safe, stay thinking!