Refining the Way Fires Are Fought In One-Story Commercial Buildings -- Part 2 If thermal imaging capability is available, use it early for interior operations. A camera should go in with the first entry team, being careful that the member using the unit is disciplined enough to stay close to...
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The lesson learned from this unusual fire is that a presence of multiple spot fires is a possible indication of a metal deck roof fire. The fire will spread in the roof and drop tar in separate locations. You may conclude you have an arson fire at first glance, unaware of the danger lurking above. Don't be deceived by "the obvious."
Multiple false ceiling grids, overhead lighting and wiring can present serious entanglement issues for crews below should they come down. Look for the absence of interior columns, which could indicate the presence of trusses above you -- again, avoid the center, which is the weakest area. If visibility allows you to see a "doubling up" of trusses -- either by way of an exposed roof deck/no ceiling or by probing the ceiling plenum area -- that is an obvious indication they are carrying an increased load (i.e., an air conditioning package unit on roof).
Beware of high shelving or storage in stores or warehouses and heavy objects on them that can do great harm should they fall on you. Beware of heavy storage in possible attic areas above you in older buildings. Mezzanines or above-grade storage systems may not be constructed to building code standards and can quickly fail when exposed to fire, crushing firefighters or blocking their escape.
Even if the building is sprinklered, the water coming out of the heads may not be reaching the seat of the fire due to obstructions such as shelving, storage and ornamental ceiling or light fixtures. Heads may even be positioned between exposed ceiling joists in restaurant-type occupancies, blocking their spray pattern range. The flowing heads will indicate you are near the seat of the fire though. Although this goes against everything you've been taught, if the sprinklers are not doing their job, then locate the valve and shut the system down once lines are in place and flowing. This also reduces further damage and the waste of precious water.
In a strip-mall setting, remember that these heads are pulling water from the same fire main as your attack lines and at that point all water should be directed toward the fire units operating on scene for both their safety and meeting flow demand. The majority of these mains, many times on a "loop," typically run six to eight inches in diameter -- barely enough for one good master stream or two or three handlines, so if non-performing sprinklers are competing for the same water as attack lines, they should be isolated.
Always have your second-due engine tap into a hydrant on the main thoroughfare running by the building/complex if you're using the proprietary one. You'll need the water for additional lines or aerial streams and you won't be stealing each other's water from the same main in the scene area. Have the police protect those lines from vehicle traffic. Try to ensure the sprinkler system is put back in service before leaving the scene, if it can be done.
Be aware of possible basements and their related hazards below you. Also, constantly be aware of the drawback to modern firefighting encapsulating gear -- the thermal protection is so good now, firefighters can easily penetrate too deep into a serious fire without knowing it (if the fire is beyond the control of a single attack line).
Be sure to get the power company on scene early into the fire and remove all electricity to the building (the same goes with the gas company), eliminating the risk to firefighters being exposed to hazards while operating inside; i.e., pulling ceilings, opening walls, operating around collapsed ceilings with dangling wires, etc. Suspect the presence of auxiliary power generators in occupancies that use large refrigeration units, such as grocery stores. Having the power company remove the primary load will only result in transferring some of it over to on-site generators. On the exterior, be aware of overhead power lines possibly hidden in smoke.
When personnel are going to the roof to ventilate, another ladder should always be raised to the roof (preferably in the rear), providing an alternate means of rapid egress for the roof team should the path back to the aerial ladder in the front of the building become obstructed. A hose should be stretched to the roof for protection as well whenever possible. Although cumbersome, self-contained breathing apparatus (SCBA) should be worn, with personal alert safety system (PASS) devices on. If you and/or your team falls through the roof, rescue crews can quickly locate you and you may need that airpack, if still intact.