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VentilationObjectives The student will:• Understand the importance of
ventilation.• Be able to identify when and where to
ventilate. • Understand the dangers of ventilation.• Be able to identify the different types of
roof construction.
Ventilation
Objectives Con’t• Know the different tools used for
ventilation. • Know how to explain and perform
vertical ventilation.
Ventilation
Overview• Importance of ventilation• Different techniques • Advantages and disadvantages• Precautions and dangers • Roof Types, and their construction• Tools needed for ventilation
Ventilation
• The systematic removal and replacement of heated air, smoke, and gases from a structure with cooler air
Ventilation
Ventilation
Advantages• Rescue• Increases survivability of trapped victims• Improves visibility, and reduces heat
levels• Reduction of flashover and backdraft
potential• Fire attack• Fire spread control• Property Conservation
VentilationDisadvantages or Improper Ventilation• Fire spread• Accelerated burning• Puts firefighters in danger• Triggers Backdraft• Structural Integrity
VentilationDangers of ventilations• Light weight construction.• Can cause fire to intensify and spread.• Places firefighters in danger.• Backdrafts.• Weather conditions.
Ventilation
Complications• Lack of Pre-planning• Barred/Screen windows.• Overhead obstructions.• Access• Weather• Improper equipment• Man power
VentilationComplications (Con’t)• Visibility• Roof pitch/type
VentilationPerform Initial Size-up
• Life Safety• Conventional or Lightweight
Construction• Determine type and style of roof• Location/Extension of fire• Weather conditions• Does the roof look safe (risk vs benefit)
VentilationConventional Construction
• Size of structural members = strength
VentilationLight weight Construction
• Trusses• Members are under compression and
tension• Size of individual members are small• If one member fails, other members may
fail
VentilationSafety Considerations
• Minimum of two ladders for egress• Approach from uninvolved• Ladder strong areas of the roof• Ladder extended 5 rungs above roof line• Shut down saws before climbing• Minimum of 2 firefighters
VentilationSafety considerations Cont.
• Full PPE/SCBA• Utilize Portable Radio• Sound the roof!!!!!!• Watch out for guy wires/electrical wires• Coordinate cut with command• Keep the wind at your back• Work from weak to strong area of roof
VentilationSafety considerations Cont.• Always know your egress routs• Perform ongoing size-up• Only cut as deep as necessary• Do not cut structural supports• Cut away from your body• Make the cut as close over the fire as
possible
VentilationSafetyConsiderations Cont.
• Advise command when ventilation is complete
• Exit roof ASAP
Whe
nW
here
How
?
VentilationVentilation Size-up • Is there a need. (Why)
• Where is it needed. (Where)
• Type needed. (How)
• Structural conditions allow for safe operations.
Timing (When)
VentilationCoordinated Fire Attack
• Vent as close to the point of origin as possible coordinating with interior attack crew.• Hose line ready and charged while
firefighters are advancing.• Ventilation of the fire room with outside
vent person.
Primary Consideration
RESCUE OR SUPPRESSION
PRIORITY WITH INTERIOR ATTACK
To keep smoke, heat, and gases away from
victim.
To reduce heat and Increase visibility
For firefighters
VentilationVertical Ventilation Opening the roof or using existing roof
opening to allow heated gases and smoke to escape.
Ventilation
Roof openings• Cut large opening
– Minimum 4’x4’– Windward side
• Smaller openings– May be necessary do to conditions
• Trench cut– From Exterior wall to exterior wall– 4’ wide
VentilationVertical Ventilation• Uses:• Attics• Areas open to the roof
Ventilation
Ventilation
VentilationRoof Construction• Lightweight wood or metal joist• Heavy steel trusses• Wood “I” beams• Built-up roof• Concrete Roofs• Metal roofs
VentilationLightweight wood or metal trusses• Trusses in place of rafters• Wood or metal decking• Built-up roof• Allows horizontal fire spread • Fails after 5-10 minutes of fire exposure
VentilationHeavy steel trusses• Metal decking with built-up roof• Starts to fail at 1000 degrees
Ventilation
Wood “I” beams• Substitute for lightweight trusses• Contributes fuel to the fire• Fails within 5 to 10 minutes of fire
exposure
Ventilation
Concrete roofs• Precast concrete• Lightweight concrete• Reinforced concrete• To vent this type is difficult and time consuming• Use natural openings, skylights, scuttles,
ventilators, stairwells
Ventilation
Metal roofs• Light-gauge steel• Corrugated galvanized sheet metal• Aluminum• Vent with power saws using metal cutting
blades, axe, or sheet metal cutters.• Use natural openings
Ventilation
Flat Roof• Industrial, commercial, and apartment
buildings• Frequently pierced by chimneys, vent
pipes, shafts, scuttles, and skylights• May be surrounded and or divided by
parapets• May have HVAC unit on them
VentilationFlat roof construction• Wooden, metal, or concrete joist• Wooden or metal decking• Waterproof materials, insulation, gravel• Reinforced, lightweight concrete, or
precast concrete
VentilationBuilt-up roof construction
OR PLYWOOD
GRAVEL
Ventilation
Built-up Roof• Opening built-up roof
– Remove gravel if present– Make inspection cut– Cut insulation and composition down to
decking– Remove materials, sound roof for rafters or
bar joist, then cut decking and remove.– Be careful not to cut to deep to avoid causing
structural damage to the rafters
Ventilation
VentilationOpening a flat roof • Determining the location of the opening
– Location and extent of fire – Wind direction– Exposures– Obstructions
• Open using the built-up roof method.
Ventilation
Pitched Roofs• Rafters or trusses• 1X boards or plywood sheeting• Felt paper• Shingles- wood, asbestos, composition,
metal, slate or terracotta tile.• May be gypsum slabs, approximately 2”
thick, laid between metal trusses.
Ventilation
VentilationOpening a pitched roof• Determine the location of the opening
same as flat roof• Place roof ladder on the windward side
of opening• Locate the rafters• Cut opening working the farthest
distance from you towards yourself• Remove the decking• Push a tool into the hole to open a
possible ceiling below
Ventilation
Arched Roofs• Bowstring truss• Trussless arched roof• Lamella roof
Ventilation
VentilationOpening an arched roof
• Cutting is the same as a pitched roof• Use of a roof ladder would be unlikely• Because of the potential for sudden collapse
under fire conditions, roof operation should be done from an aerial ladder or tower.
Ventilation
Hand tools• Axe• Halligan bar• Pike poles• Sledge hammer• Ladders
Ventilation
Power tools• Vent saws• Chain saws• Circle saws• Reciprocating saws
Ventilation
Power tool safety• Proper maintenance• Know tool operations and capabilities• PPE• Start tool before taking to operational
area• Never carry, hoist, or climb while
running• Keep front arm stiff while operating tools• Work with a partner
Ventilation
Review• Discussed the importance of ventilation• Discussed the advantages and disadvantages
of ventilation• Discussed precautions and dangers of
ventilation• Discussed the different types of roofs, and their
construction• Discussed the tools needed for ventilation
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