WARNING!

1
WARNING!

• FIREFIGHTERS ARE FREQUENTLY
• INJURIED OR KILLED WHEN
• BURNING STRUCTURES
• COLLAPSE WITH OUT WARNING

2
Firefighter Hazards Related to Building
Construction

• The primary objective of understanding building
  construction and materials is to apply this
  information to the fireground.
• Firefighters should use this knowledge to monitor
  signs of structural instability.

3
Dangerous Building Conditions

• There are two primary types of dangerous
  conditions that may be posed by a building.
• 1. Conditions that contribute to the spread
  intensity of the fire.
• 2. Conditions that make the building susceptible
  to collapse.

4
Terms

• CONCENTRATED LOAD - Load applied to a small area,
  example a/c unit placed on a roof structure
• DEAD LOAD The weight of the building materials
  and any part of the building permanently attached
  to it.
• DESIGN LOAD A load the designer planned for in
  the building design.
• UNDESIGNED LOAD A load not planned for.
• DISTRIBUTED LOAD A load applied equally over an
  area.

5

• FIRE LOAD All the parts or contents of a
  building that will burn. The amount of heat
  released from a fuel in lbs\sq ft.
• LIVE LOAD The weight of all materials and
  people associated with but not part of the
  structure.
• IMPACT LOAD a load that is in motion when it is
  applied. This could be a hose stream striking
  the side of the building.

6
Application of Loads

• AXIAL LOAD A load padding through the center of
  the mass of the supporting element, perpendicular
  to its cross section.
• ECCENTRIC LOAD - a load perpendicular to the
  cross section of the supporting element that does
  not pass through the center of mass.
• TORSION LOAD A load parallel to the cross
  section of the supporting member that does not
  pass through mass.

7
Application of Loads Pictures
8
Loads applied to structural elements as forces

• COMPRESSION A force that tends to push
  materials together.
• TENSION A force that pulls materials apart.
• SHEAR A force that tends to break material by
  causing its molecules to slide past each other.

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Types of Loads picture
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COMMERCIALBUILDINGS
11
Building Collapse

• Knowledge of the type of construction is vital
  during fire operations because of the possibility
  of collapse.

• Some buildings because
• of their age construction
• are more inclined to
• collapse than others.

12
Collapse Zone
13
Indictors of Possible Building Collapse

• Cracks or separations in walls, floors ceiling
  and roof structures
• Evidence of existing structural instability such
  as the presence of tie rods stars that hold
  walls together.
• Loose bricks, blocks or stones falling from
  buildings

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Deterioration of mortar between masonry
Cracks or separations in walls, floors, ceilings
roof structure
15
Signs of collapse

• Deterioration of mortar between the masonry
• Walls that appear to be leaning
• Structural members that appear to be distorted
• Fire beneath floors that support heavy machinery
  or other extreme weight loads.

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Signs of collapse

• Prolonged fire exposure to the structural members
• Unusual creaks and cracking noises
• Structural members pulling away from walls
• Excessive weight of building contents

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Parapet Wall Collapse
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RESIDENTIALCOLLAPSE
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Parallel Chord Truss
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Wood Trusses
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Truss Construction Void Spaces
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Types of Construction

• Truss construction
• Bowstring trusses
• Wood trusses
• Open web steel joist
• Void spaces
• Engineering wood structural members
• Roof structures
• Parapet walls
• Synthetic materials
• Fire-resistive and noncombustible
  construction

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WRAP-UP

• Firefighters must know and understand building
  construction.
• There are five common types of construction.
• Truss construction is dangerous because trusses
  collapse under fire conditions.
• Firefighters need to be aware of the hazards
  associated with structure fires.