BUILDING CONSTRUCTION 1
The evolving nature of the fireground demands an in-depthunderstanding of building anatomy and occupancy risk profiling. Thecharacteristics of a structure under fire conditions must beidentified, assessed, and predicted with accuracy. Regrettably, morethan 1,000 firefighters have perished in burning buildings within thelast decade (Naum, 2015). In many instances, crews disregard orminimize the potential for structural compromise. Others lackin-depth knowledge of the building and construction framework (Naum,2015). Operational risks during structure fires are heightened bycompromised attention to subtle pre-collapse indicators and thereduced levels of situational awareness.
Type I buildingsare constructed with fire-resistant materials (Frassetto, 2012). Inthis regard, roofs, floors, beams, columns, and walls are made oflimited-combustible or non-combustible substances. Similarly, type IIbuildings utilize non-combustible construction techniques. However,the latter structures have a relatively lower degree of fireresistance (Frassetto, 2012). On the other hand, type III buildingsutilize ordinary construction procedures. Consequently, interiorstructures such as roofs, floors, beams, columns, and walls arepartially or wholly made of wood while exterior walls are constructedwith limited combustible materials. Type IV buildings are made ofheavy timber such that the wood has large dimensions (Frassetto,2012). Interior and exterior walls are constructed usinglimited-combustible or non-combustible materials (Frassetto, 2012).Nonetheless, interior structures such as roofs, floors, arches,columns, and beams are made of laminated or solid wood withoutconcealed spaces. Type V buildings are partially or entirelyconstructed with wood (Frassetto, 2012). In fact, roofs, floors,bearing walls, and exterior walls are made of wood or othersubstances with smaller dimensions than the materials used in heavytimber construction.
Buildings withparticular types of codes have HVAC systems and self-pressurizingstairwells that contribute to air movement (Frassetto, 2012).Elevators and fire pumps are established in some structures dependingon the classification. Hence, firefighters must study the local codesto know the various features found within the buildings. Type IIstructures are customarily built up to code and hence encompass firesuppression mechanisms (Frassetto, 2012). Moreover, type III buildingcodes have ledger walls that act as a safe perch for firefighters.Type IV structures are easily recognizable through the long distancebetween roof spans. Since the buildings were constructed before 1960,they use metal plates and bolts as connectors (Frassetto, 2012).Despite the thickness of the roof decking, vertical ventilation canbe achieved in these structures. In addition, type V building codesallow aeration to occur through asphalt shingles (Frassetto, 2012).It is imperative to remove tiles before attempting to cut holes intothe roof. Type V structures could also benefit from positive-pressureattacks.
The type of thestructure determines the appropriate method adopted by thefirefighters. For example, type I buildings are customarilyfire-resistive since they are constructed of protected steel andconcrete (Frassetto, 2012). The metal alloy prevents fire fromspreading to other rooms within the structure (Steelworks, 2016).Granted, type I buildings do not allow the usual ventilation practiceof cutting a hole in the roof (Frassetto, 2012). Additionally, thestructure has tempered glass and thick windows. Consequently, itbecomes impossible to create horizontal ventilation. Aggressivetechniques should be used to secure the stairwells during theevacuation of both victims and firefighters (Frassetto, 2012). Type Ibuildings require crews to maintain proper working relationships withmaintenance workers (Frassetto, 2012). Such associations are neededdue to the complex nature of fire-related systems and protection.
In manyinstances, newer commercial buildings have type II construction. Suchstructures are susceptible to early collapse in cases where there isa considerable fire load (Frassetto, 2012). Some firefighters soundthe walls to decipher whether the building is constructed withcombustible material (Frassetto, 2012). Rooftop and ladder crewmembers should collaborate to cut inspection holes and create naturalventilation from roll-up doors (Frassetto, 2012). Nonetheless, toolssuch as circular saws and chainsaws would not suffice to cut largeopenings for the benefit of interior crews.
Type IIIbuildings with older construction techniques have conventionallyframed roofs and unreinforced masonry. On the other hand, those withnewer forms have lighter roof systems reinforced with tilt slabs.Notably, arched lintels, king’s rows, and collar ties experienceextensive weathering (Frassetto, 2012). Hence, firefighters can usechainsaws to cut holes for ventilation. However, newer types ofstructures utilize truss systems in both parallel and panelized rooftypes. Direct fire causes rapid disintegration of modern buildings(Frassetto, 2012). Therefore, vertical ventilation is both effectiveand feasible. Firefighters can identify type IV buildings through theuse of large sections of lumber. Heavy timber structures canwithstand fire conditions for some time. Nevertheless, such buildingsare susceptible to early collapse due to years of poor maintenanceand weathering (Frassetto, 2012). Consequently, firefighters must bealert to avoid adopting a misleading sense of security.
Many modernhouses embrace type V construction, which uses combustible materials.Wood is mostly used to frame the rooftops and walls. Inevitably,direct fire impingement leads to the destruction of type V buildingswithin a few minutes (Frassetto, 2012). Consequently, firefightersshould act with urgency to save some property. Rooftop crews mustsound the walls to determine whether alternatives may be used in thecase of a heavy attic (Frassetto, 2012). Furthermore, interior crewsneed to be wary of flashovers in the event where a fire is restrictedin one room. Hence, it would be beneficial to pursue aggressiveventilation.
BuildingCollapse and Awareness
The collapse of abuilding on fire is determined by various interrelated factors. Forexample, it is critical to consider the exposure and extension offire (Naum, 2015). The behavior and dynamics of the blaze alsocontribute to the environmental impact of suppression activities.Moreover, it is important to establish the occupancy use,deterioration, and age of a burning building (Naum, 2015). Theformulation and implementation of incident action plans must beguided by the edifice’s likelihood of undergoing structuralcollapse. Other factors include the failure or compromise based onthe building’s performance (Naum, 2015). Furthermore, collapseindicators or precursors should be highlighted and monitored byoperating companies, supervisors, and incident commanders.
Inevitably,conducting safe firefighting operations is dependent on understandinga building’s structural anatomy and design (Sullivan, 2012). Thesurvivability of firefighters is intricately linked to the impact offire on the construction methodology and integration of structurematerials. Proper management of the fireground can be achievedthrough the use of operational exclusion areas and collapse zones(Naum, 2015). Notably, structural collapse could occur internally orexternally around a building’s perimeter (Naum, 2015). The highestrisk lies in the fireground perimeter due to several factors such asthe proximity of tactical operations, staged personnel, apparatuspositioning, and the structure’s egress and access points (Naum,2015). Firefighting personnel must avoid collapse areas that threatenthe perimeter walls and parapets.
Besides,firefighters must maintain situational awareness at all times in thecourse of rescue operations. In this respect, they must remain alertto escalating fireground conditions and factors (Mason, 2013).Firefighters must also observe their surroundings to ensure thesafety of fellow team members. Mental awareness would help them tomonitor the fire’s progress and effects on the interior andexterior structures (Mason, 2013). Situational awareness isinfluenced by several factors such as poor communication anddecision-making. In addition, command officers must utilize dynamicrisk assessment strategies to deal with the changing circumstances offiregrounds (Mason, 2013).
All firefightersmust have a constant awareness of their location, situation, and airsupply (IAFC, 2011). Team members should confirm that they have afull bottle of air before entering a burning building. Subsequently,they must exit the structure before they discern the low air alarm(IAFC, 2011). Frequent checks of air supply should be done before andafter the performance of laborious tasks. Such a precaution isessential since more oxygen is inhaled during strenuous activity(IAFC, 2011). Hence, firefighters ought to know their personalconsumption rates. Ongoing air-supply reports enable the incidentcommander to discern when it would be prudent to summon fresh crewmembers.
Deficiency insituational awareness occurs when firefighters fail to notice thedifference between their perception and reality (IAFC, 2011). Hence,unexpected events can surprise them to the extent of causing injuryor death in extreme cases. Situational awareness is mostly influencedby a lack of cognition, knowledge, and information (IAFC, 2011).Firefighters are prone to misinterpreting safety instructions. Theycould also acquire incomplete information on their surroundings.Moreover, a narrow focus would impede them from considering the fullrange of factors within their environment (IAFC, 2011). Although afire may be under control, the structural integrity of the buildingcould be compromised to the extent of leading to instantaneouscollapse.
It is crucial forfirefighters to listen to and understand all messages communicatedvia the radio channel (IAFC, 2011). In some cases, worseningconditions at particular locations could endanger crew members inother areas. It is also essential to remember the pathways used toenter the building and access rooms (IAFC, 2011). Landmarks can helpthe firefighter to exit the structure in case they are separated fromother team members. Detailed and accurate descriptions of thebuilding can help personnel who are trapped in the fire (IAFC, 2011).The turn-around point should be respected to avoid exhausting the airsupply while in the structure.
Indeed,operational risks encountered in firegrounds are exacerbated byreduced situational awareness and the lack of sufficient knowledgeconcerning building construction. There are five types of structureswith unique codes and reaction to fire. Wood-framed buildings havethe highest risk of suffering destruction while fire-resistiveedifices can resist prolonged burning. The inherent dangersassociated with firegrounds require firefighters to take sufficientprotective measures. For example, they must maintain constantsituational awareness of their conditions and air supply.Subsequently, they will pay keen attention to signs of buildingcollapse to avoid being trapped. Furthermore, firefighters willdesist from taking unnecessary risks, especially when property andlives cannot be saved.
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Frassetto, R. (2012, February 1). Understanding building constructiontypes. Firefighter Nation. Retrieved fromhttp://www.firefighternation.com/article/truck-co-operations/understanding-building-construction-types
IAFC. (2011, September 15). Rules of Engagement for FirefighterSurvival: Maintain Continuous Awareness. International Associationof Fire Chiefs. Retrieved fromhttp://www.iafc.org/MemberCenter/OnSceneArticle.cfm?ItemNumber=5087
Mason, M. (2013, January 3). Surviving the fireground. FireEngineering. Retrieved fromhttp://www.fireengineering.com/articles/print/volume-166/issue-3/fdic-preview/surviving-the-fireground.html
Naum, C. J. (2015, March 31). Establishing collapse zones at buildingfires. Firehouse. Retrieved fromhttp://www.firehouse.com/article/12054302/establishing-collapse-zones-at-building-fires
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Sullivan, J. (2012). ISO’s role when transitioning from anoffensive to a defensive attack. FireRescue, 86–89.