13. Structural Collapse.pdf

Policy Lehigh Acres Fire Control and Rescue District 528 Fire Services Manual Structural Collapse 528.1 PURPOSE AND SCOPE: The purpose of this policy is to establish a guidance for warning signs of an structural collapse, while operating at an incident. 528.2 POLICY: It is the policy of the Lehi...

Policy Lehigh Acres Fire Control and Rescue District 528 Fire Services Manual Structural Collapse 528.1 PURPOSE AND SCOPE: The purpose of this policy is to establish a guidance for warning signs of an structural collapse, while operating at an incident. 528.2 POLICY: It is the policy of the Lehigh Acres Fire Control and Rescue District to utilize the Incident Command System (ICS) for managing structural collapse incidents. 528.3 PROCEDURE: (a) In recent times structural collapse has been one of the leading causes of serious injuries and death to firefighters. For this reason, the possibility of structural collapse should be a major consideration in the development of any tactical plan. (b) Structural collapse is always a possibility when a building is subject to intense fire. In fact, if fire is allowed to affect a structure long enough some structural failure is inevitable. (c) Regardless of the age and exterior appearance of the building, there is always the possibility that a principal structural supporting member is being seriously affected by heat and may collapse suddenly inflicting serious injury to firefighters. (d) In the typical fire involved building, the roof is the most likely candidate for failure, however failure of the roof may very likely trigger a collapse of one or more wall sections. This is especially true if the roof is a peak or dome type, which may exert outward pressure against both the bearing and non#bearing walls upon collapse. In multi-story buildings or buildings with basement, the floor section above the fire may collapse if supporting members are directly exposed to heat and flames. (e) A knowledge of various types of building construction can be invaluable to the Fire Officer from a safety standpoint as certain types of construction can be expected to fail sooner than others. For example: under fire conditions lightweight truss and bar joist roof construction can be expected to fail after minimal fire exposure. (f) Structures have been known to collapse without warning but usually there are signs, which may tip off and alert a fire officer. Action might be taken to avert any imminent hazard. (g) Tell Tale Signs (Red Flags): 1. Cracks in exterior walls. 2. Bulges in exterior walls. 3. Sounds of structural movement # creaking, growling, snapping, etc. 4. Smoke or water leaking through walls. 5. Flexible movement of any floor or roof where firefighters walk. Copyright Lexipol, LLC 2023/05/22, All Rights Reserved. Published with permission by Lehigh Acres Fire Control and Rescue District Structural Collapse - 1 Lehigh Acres Fire Control and Rescue District Fire Services Manual Structural Collapse 6. (h) Interior or exterior bearing walls or columns leaning, twisting, or flexing. The following construction features or conditions have been known to fail prematurely or to contribute to early structural failure when affected by fire. Contributing Factors: 1. Large (unsupported) areas # supermarkets, warehouses, etc. 2. Large signs or marquees, which may pull away from weakened walls. 3. Cantilevered canopies, which usually depend on the roof for support and may collapse as the roof fails. 4. Ornamental or secondary front or sidewalls, which may pull away and collapse. 5. Buildings with lightweight truss, bar joist, or bow string truss roofs. 6. Buildings supported by unprotected metal beams, columns, etc. (i) Buildings containing one or more of the above features must be constantly evaluated for collapse potential. These evaluations should be of major consideration toward determining the tactical mode, i.e. offensive/defensive. (j) It is a principal COMMAND responsibility to continually evaluate and determine if the fire building is tenable for interior operations. This on#going evaluation of structural/ fire conditions requires the input of company officers advising COMMAND of the conditions in their area of operation. (k) Structures of other than fire protected/heavy timber construction are not designed to withstand the effects of fire and can be expected to fail after approximately twenty minutes of heavy fire involvement. If, after 10#15 minutes of interior operations, heavy fire conditions still exist, COMMAND should initiate a careful evaluation of structural conditions and should be fully prepared to withdraw interior crews and resort to a defensive position. (l) If structural failure of a building or section of a building appears likely, a perimeter must be established a safe distance from the area that may collapse. All personnel must remain outside this perimeter. Copyright Lexipol, LLC 2023/05/22, All Rights Reserved. Published with permission by Lehigh Acres Fire Control and Rescue District Structural Collapse - 2