roof operations - la county firefighters · bowstring arch similar in appearance to ribbed arch and...

ROOF OPERATIONSROOF OPERATIONS

COURSE OUTLINECOURSE OUTLINE

IntroductionIntroductionPART IPART I--Phases of Structure FiresPhases of Structure FiresPART IIPART II--Roof ConstructionRoof ConstructionPART IIIPART III--Tactical ConsiderationsTactical ConsiderationsPART IVPART IV--Ventilation MethodsVentilation Methods

INTRODUCTIONINTRODUCTION

A considerable portion of the annual loss of life and A considerable portion of the annual loss of life and property is a direct result of the lack of timely, property is a direct result of the lack of timely, effective ventilationeffective ventilation80% of all fire fatalities are due to smoke inhalation80% of all fire fatalities are due to smoke inhalationMore than oneMore than one--half of the nations fire loss is a direct half of the nations fire loss is a direct result of smoke and heat damageresult of smoke and heat damageVentilation has a direct effect on all aspects of fire Ventilation has a direct effect on all aspects of fire fighting strategiesfighting strategies

PART IPART I

PHASES OF STRUCTURE FIRESPHASES OF STRUCTURE FIRES

PHASES OF STRUCTURE FIRESPHASES OF STRUCTURE FIRES

Structure fires progress through three Structure fires progress through three basic phases:basic phases:–– Incipient or Beginning PhaseIncipient or Beginning Phase–– Steady State or FreeSteady State or Free--Burning PhaseBurning Phase–– Hot Smoldering PhaseHot Smoldering Phase

THE INCIPIENT / BEGINNING PHASETHE INCIPIENT / BEGINNING PHASE

Oxygen content approximately 21%.Oxygen content approximately 21%.Carbon dioxide, sulfur dioxide, carbon Carbon dioxide, sulfur dioxide, carbon monoxide and water vapor produced.monoxide and water vapor produced.The flame temperature can be above 1000 The flame temperature can be above 1000 degrees, while room temperature may only degrees, while room temperature may only be slightly elevated. be slightly elevated.

Phases of FirePhases of Fire

STEADY STATE / FREESTEADY STATE / FREE--BURNING PHASEBURNING PHASE

Adequate oxygen and fuel sustain freeAdequate oxygen and fuel sustain free--burning and fire growth to the point of burning and fire growth to the point of full involvement of area/room.full involvement of area/room.–– MushroomingMushrooming–– FlashoverFlashover

Phases of firePhases of fire


MushroomingMushrooming–– Smoke and gases are heated.Smoke and gases are heated.–– If confined to a room or building, they will rise If confined to a room or building, they will rise

to the uppermost level.to the uppermost level.–– Cooler air is displaced down towards the fire, Cooler air is displaced down towards the fire,

providing oxygen and sustaining combustion.providing oxygen and sustaining combustion.–– As circulation occurs, heated smoke and gases As circulation occurs, heated smoke and gases

build internal pressure that continue to rise build internal pressure that continue to rise and spread laterally.and spread laterally.



FlashoverFlashover–– A simultaneous ignition over the surface of A simultaneous ignition over the surface of

the room or area.the room or area.–– Occurs when the heat from the fire raises Occurs when the heat from the fire raises

the temperature of the contents to their the temperature of the contents to their ignition temperatures.ignition temperatures.

–– The ignition happens in an instant.The ignition happens in an instant.–– Effects may be deadly to firefightersEffects may be deadly to firefighters


HOT SMOLDERING PHASEHOT SMOLDERING PHASE

If the freeIf the free--burning state remains unburning state remains un--vented, vented, the fire progresses into the hot smoldering the fire progresses into the hot smoldering phase.phase.–– Low oxygen levels with little or no flame production.Low oxygen levels with little or no flame production.–– Temperatures in excess of 1000 degrees.Temperatures in excess of 1000 degrees.–– Dense black smoke, that pressurizes the area.Dense black smoke, that pressurizes the area.–– Intense heat continues to vaporize lighter fuels.Intense heat continues to vaporize lighter fuels.–– These gases greatly increase the chance of a These gases greatly increase the chance of a

backdraft.backdraft.


HOT SMOLDERING PHASEHOT SMOLDERING PHASE

BackdraftBackdraft–– A confined area that is teeming with A confined area that is teeming with

pressurized, heated and flammable gases.pressurized, heated and flammable gases.–– The introduction of oxygen to this fuelThe introduction of oxygen to this fuel--rich rich

environment will result in an explosion of environment will result in an explosion of significant intensity.significant intensity.

–– Effects may be deadly to firefightersEffects may be deadly to firefighters


Part IIPart II

ROOFROOFCONSTRUCTIONCONSTRUCTION

Roof ConstructionRoof Construction

The firefighters ability to safely and efficiently The firefighters ability to safely and efficiently ventilate a building through the roof will ventilate a building through the roof will depend to some degree on his understanding depend to some degree on his understanding of roof constructionof roof constructionIt is essential that firefighters become familiar It is essential that firefighters become familiar with the existing and newly constructed with the existing and newly constructed buildings within their response areabuildings within their response area


Conventional Conventional

VSVSLightweightLightweight

CONVENTIONAL CONVENTIONAL CONSTRUCTIONCONSTRUCTION

Structural members depend on size for Structural members depend on size for strength.strength.Less surface area exposed to fire.Less surface area exposed to fire.The larger the size of a structural The larger the size of a structural member, the longer it will take to fail member, the longer it will take to fail when exposed to fire.when exposed to fire.Potentially longer burn time results in a Potentially longer burn time results in a greater window of safety for fire greater window of safety for fire fighters.fighters.

Conventional ConstructionConventional Construction


Arched TrussesArched Trusses

Buildings built during the 1930Buildings built during the 1930’’s and s and 19401940’’s commonly used truss s commonly used truss construction.construction.Truss members have the same strength Truss members have the same strength relationships as lightweight only much relationships as lightweight only much stronger.stronger.


Bridge TrussesBridge TrussesBuildings built in the 1920Buildings built in the 1920’’ss--19401940’’s s not as common as the archnot as common as the archRoofs vary in size and slightly in Roofs vary in size and slightly in designdesignTop surface is basically a flat roofTop surface is basically a flat roof


Conventional ResidentialConventional Residential


RAFTERS AND SPACE RAFTERS AND SPACE SHEETINGSHEETING


Conventional ConstructionConventional Construction

Firefighter ConcernsFirefighter Concerns–– Generally sound constructionGenerally sound construction–– Strongest areas of these roofs are ridges, Strongest areas of these roofs are ridges,

hips, valleys, over trusses and where hips, valleys, over trusses and where rafters cross outside wallsrafters cross outside walls

–– Size of structural member dictates fire Size of structural member dictates fire exposure time prior to failureexposure time prior to failure

–– Heat holes are acceptable and preferred Heat holes are acceptable and preferred with this type of constructionwith this type of construction


LIGHTWEIGHT LIGHTWEIGHT CONSTRUCTIONCONSTRUCTION


Lightweight construction:Lightweight construction:

Does not derive its strength from size.Does not derive its strength from size.Strength obtained from multiple Strength obtained from multiple members in compression and tension.members in compression and tension.Involves the use of less fire resistive Involves the use of less fire resistive materials.materials.Provides less time to ventilate before Provides less time to ventilate before the roof becomes unstable.the roof becomes unstable.


Lightweight ConstructionLightweight Construction

General RulesGeneral Rules–– Expect early and complete collapseExpect early and complete collapse–– No heat holesNo heat holes–– Cut vent holes well ahead of fireCut vent holes well ahead of fire–– 3/83/8--1/21/2”” decking offers little resistance to decking offers little resistance to

firefire–– Time on these roofs is very limitedTime on these roofs is very limited


Major types of Lightweight roof Major types of Lightweight roof constructionconstruction

Metal Gusset Plate Trusses.Metal Gusset Plate Trusses.Wooden Wooden ““II”” Beam.Beam.Open Web Truss. Open Web Truss. Open Web Steel Joist Open Web Steel Joist PanelizedPanelized


Metal Gusset Plate Trusses:Metal Gusset Plate Trusses:

Common in residential and commercial Common in residential and commercial buildings.buildings.Usually 2Usually 2”” x 4x 4”” lumber butt jointed and held lumber butt jointed and held together by metal gusset plates commonly together by metal gusset plates commonly known as known as ““gang nailgang nail”” which are 3/8which are 3/8”” in depth.in depth.Characterized by a top (compression) chord Characterized by a top (compression) chord and bottom (tension) chord.and bottom (tension) chord.Spans up to 80Spans up to 80’’ with trusses 2with trusses 2’’ on centeron center


Lightweight CommercialLightweight Commercial

Metal gusset plateMetal gusset plate


Metal Gusset PlatesMetal Gusset PlatesRoof ConstructionRoof Construction

Metal Gusset PlatesMetal Gusset Plates

––Burn testBurn test--structural collapse structural collapse 1min. 20 sec.with direct flame 1min. 20 sec.with direct flame impingementimpingement


Metal Gusset platesMetal Gusset plates

Firefighter ConcernsFirefighter Concerns–– Gusset plates increase charring at joints Gusset plates increase charring at joints

resulting in failureresulting in failure–– Bottom chord or web failure causes truss Bottom chord or web failure causes truss

failurefailure–– Open space between chords promotes fire Open space between chords promotes fire

spreadspread


Wooden Wooden ““II”” Beam:Beam:

Top and bottom chord of 2Top and bottom chord of 2”” x 3x 3”” or 2or 2”” x x 44””..The stem is normally 3/8The stem is normally 3/8”” plywood or plywood or OSB glued in place.OSB glued in place.Common spacing is 2Common spacing is 2’’ on center.on center.Strongest location is where the roof Strongest location is where the roof meets the exterior wall.meets the exterior wall.


Wooden Wooden ““II”” BeamBeam



Burn testBurn test--structural collapse 3 min. 15 structural collapse 3 min. 15 sec. With direct flame impingement.sec. With direct flame impingement.



Firefighter ConcernsFirefighter Concerns–– Stem has very little relative mass and Stem has very little relative mass and

burns to failure quickly.burns to failure quickly.–– ““Poke throughPoke through”” construction reduces truss construction reduces truss

strength and promotes fire spreadstrength and promotes fire spread


Open Web Trusses:Open Web Trusses:

Wooden top and bottom chord cross Wooden top and bottom chord cross connected by steel tube web members.connected by steel tube web members.2x3 or 2x4 chords with spans of up to 2x3 or 2x4 chords with spans of up to 7070’’..Normal spacing is 2Normal spacing is 2’’ on center.on center.Strongest location is where the roof Strongest location is where the roof meets the exterior wall.meets the exterior wall.


Open webOpen web

““Free hangingFree hanging”” bottom cordsbottom cords


Open Web Trusses:Open Web Trusses:

Structural collapse 4 min. 30 sec. With Structural collapse 4 min. 30 sec. With direct flame impingement.direct flame impingement.


Open Web TrussesOpen Web TrussesFirefighting ConcernsFirefighting Concerns–– This is the most lightweight of truss This is the most lightweight of truss

constructionconstruction–– Steel is good conductor of heatSteel is good conductor of heat–– Open space between cords promotes fire Open space between cords promotes fire

spreadspread


Open Web Steel JoistOpen Web Steel Joist

Steel top and bottom chords usually Steel top and bottom chords usually 1/81/8”” angle ironangle ironWebs 1/8Webs 1/8”” angle iron or 5/8angle iron or 5/8”” solid barssolid barsCorrugated metal decking is commonly Corrugated metal decking is commonly used with these trussesused with these trussesOften configured in a Often configured in a ““panelizedpanelized””fashionfashion



Firefighter ConcernsFirefighter Concerns–– Steel exposed to heat can distort and failSteel exposed to heat can distort and fail–– Consider rotary saws with carbide blades Consider rotary saws with carbide blades

for cutting steel deckingfor cutting steel decking–– Fire may travel in horizontal openings of Fire may travel in horizontal openings of

metal deckingmetal decking


Panelized ConstructionPanelized Construction

Consist of large, laminated beams spaced 12Consist of large, laminated beams spaced 12’’to 40to 40’’..Beams can span well over 100Beams can span well over 100’’..Purlins with metal hangers on 8Purlins with metal hangers on 8’’ centers.centers.Purlins may be timber or truss designPurlins may be timber or truss design22”” x 4x 4”” rafters 2rafters 2’’ on centers.on centers.Decking is usually 1/2Decking is usually 1/2”” plywood.plywood.


PANELIZED SKELETONPANELIZED SKELETON


Panelized roofs:Panelized roofs:–– Structural collapse 5 min. 20 sec. With Structural collapse 5 min. 20 sec. With

direct flame impingementdirect flame impingement



Firefighter ConcernsFirefighter Concerns–– Steel beam supports weaken and fail Steel beam supports weaken and fail

resulting in sudden collapse of large resulting in sudden collapse of large portions of roofportions of roof

–– Foil insulation adds to fire spreadFoil insulation adds to fire spread–– Strongest areas are over beams, purlins Strongest areas are over beams, purlins

and perimeter of buildingand perimeter of building


ROOF CONSTRUCTIONROOF CONSTRUCTION

Roof Styles and DesignsRoof Styles and Designs

There are three basic styles There are three basic styles of roof designof roof design

Pitched roofsPitched roofsArched roofsArched roofsFlat roofsFlat roofs

Roof StylesRoof Styles

Pitched Roof DesignPitched Roof Design

GableGableHipHipShedShedBridge TrussBridge TrussMansardMansardGambrelGambrel


GableGable

Basic ABasic A--frame design with the roof pitched in frame design with the roof pitched in two opposing planes.two opposing planes.May utilize conventional or lightweight May utilize conventional or lightweight construction.construction.Covered by shake, tile, rock, composition, Covered by shake, tile, rock, composition, etc. and supported by sheathing or plywood.etc. and supported by sheathing or plywood.


PITCHED ROOF LINESPITCHED ROOF LINES


Pitched Roof with dormersPitched Roof with dormers


HipHip

Similar to the gable roof, but lacks the ASimilar to the gable roof, but lacks the A--frame configuration.frame configuration.Two sets of opposing pitches where the roof Two sets of opposing pitches where the roof slopes down to meet every outside wall.slopes down to meet every outside wall.May utilize conventional or lightweight May utilize conventional or lightweight construction.construction.


Hip Hip RoofRoof


ShedShed

This style is essentially half a gable This style is essentially half a gable roof.roof.May utilize conventional or lightweight May utilize conventional or lightweight construction.construction.


Bridge TrussBridge Truss

Easily identified by its characteristic Easily identified by its characteristic sloping ends.sloping ends.Wooden truss members are 2Wooden truss members are 2”” x 12x 12””and constitute a heavy grade of and constitute a heavy grade of construction.construction.Rafters are 2Rafters are 2”” x 6x 6”” or larger and or larger and covered by 1covered by 1”” x 6x 6”” sheathing and sheathing and composition.composition.


Bridged truss concealed by Bridged truss concealed by supported facadesupported facade

Bridged TrussBridged Truss


Bridge TrussesBridge Trusses


MansardMansard

This roof has a double slope on each of its This roof has a double slope on each of its four sides.four sides.The lower slope is steeper than the upper The lower slope is steeper than the upper slope.slope.


Arched Roof DesignArched Roof Design

Ribbed archRibbed archLamella roofLamella roofBowstring archBowstring arch


GambrelGambrel

Pitched roof with two plans on each Pitched roof with two plans on each sidesideLower plans are steeper than upper Lower plans are steeper than upper planplanDifficult to ladder, roof ladder usually Difficult to ladder, roof ladder usually requiredrequiredLower plan may make up interior wallLower plan may make up interior wall

GambrelGambrel

Ribbed Arch TrussRibbed Arch Truss

Similar to Bridge Truss except that the top chord Similar to Bridge Truss except that the top chord is arched.is arched.Large wooden members of 2Large wooden members of 2”” x 12x 12”” to 2to 2”” x 14x 14””..Rafters (2Rafters (2”” x 6x 6”” or more) are covered with 1or more) are covered with 1”” x 6x 6””sheathing and composition roofing material.sheathing and composition roofing material.Early collapse is not a primary concern.Early collapse is not a primary concern.


Arched Truss RoofsArched Truss Roofs


Arched TrussesArched Trusses


Arched TrussArched Truss

–– This roof predictably fails in sections. This roof predictably fails in sections.


Lamella RoofsLamella Roofs

EggEgg--crate, geometric or diamondcrate, geometric or diamond--patterned patterned roof.roof.Roof decking is 1 x 6 sheathing.Roof decking is 1 x 6 sheathing.Common on gymnasiums, supermarkets and Common on gymnasiums, supermarkets and recreational buildings.recreational buildings.Total roof collapse may occur if fire removes Total roof collapse may occur if fire removes more than 20% of roof structure.more than 20% of roof structure.Failure results from the Failure results from the ““domino effect.domino effect.””


Lamella RoofLamella Roof


LamellaLamella““TellTell--Tail signTail sign””

Lamella continuous archLamella continuous arch

Bridge truss Bridge truss ““trailing endstrailing ends””

Bowstring ArchBowstring ArchSimilar in appearance to ribbed arch and lamella Similar in appearance to ribbed arch and lamella roofs, yet significantly different.roofs, yet significantly different.Metal tie rods with turnbuckles offer lateral Metal tie rods with turnbuckles offer lateral support and ensure that arch roof does not push support and ensure that arch roof does not push the exterior walls outward.the exterior walls outward.Rafters (2Rafters (2”” x 10x 10””) are covered with 1) are covered with 1”” x 6x 6””sheathing and composition roofing material.sheathing and composition roofing material.Primary hazard is early failure of the metal tie Primary hazard is early failure of the metal tie rods and turnbuckles.rods and turnbuckles.


Flat Roof DesignFlat Roof Design

Popular style for a wide variety of structures.Popular style for a wide variety of structures.It is also the most deceiving style.It is also the most deceiving style.Although it is simplistic in appearance, it varies in Although it is simplistic in appearance, it varies in construction methods and is often difficult (from the construction methods and is often difficult (from the exterior appearance) to visually determine the exterior appearance) to visually determine the method utilized, i.e.. Conventional/lightweight. method utilized, i.e.. Conventional/lightweight.


Flat Roof DesignFlat Roof Design

ConventionalConventionalWooden Wooden ““II”” beambeamOpen webOpen webOpen web bar joistOpen web bar joistMetal gusset plateMetal gusset platePanelized (may be combined)Panelized (may be combined)


Conventional construction Flat Conventional construction Flat residentialresidential

Flat commercialFlat commercial


Flat CommercialFlat Commercial


Flat Commercial with high Flat Commercial with high parapetsparapets

Live Roof LoadsLive Roof LoadsRoof StylesRoof Styles

You never know what you might You never know what you might findfind

PART IIIPART III

TACTICAL TACTICAL CONSIDERATIONSCONSIDERATIONS

Tactical ConsiderationsTactical Considerations

The decision is not, The decision is not, ““should we should we ventilate,ventilate,”” but rather, but rather, ““what type of what type of ventilation should we use and how ventilation should we use and how aggressive should we be.aggressive should we be.””


Ventilation is the first step in gaining Ventilation is the first step in gaining positive control of a fire building.positive control of a fire building.Ventilation allows all subsequent Ventilation allows all subsequent operations such as search, rescue and operations such as search, rescue and fire attack to be much more safe and fire attack to be much more safe and efficient.efficient.


Life hazard/Search and rescueLife hazard/Search and rescueLocation and extension of the fireLocation and extension of the fireType of construction (strengths/weakness)Type of construction (strengths/weakness)Means of ingress/egressMeans of ingress/egress


““An aggressive interior attack always An aggressive interior attack always has an increased life hazard riskhas an increased life hazard risk””

Life hazard/Search and rescueLife hazard/Search and rescue

Immediate ventilationImmediate ventilationFacilitate search and rescueFacilitate search and rescueRoute heat and smoke away from operationRoute heat and smoke away from operationAlways consider benefit to attack crewsAlways consider benefit to attack crews


Location and extension of the fireLocation and extension of the fire

Risk Vs GainRisk Vs GainOffensive/ DefensiveOffensive/ DefensiveSelf ventedSelf ventedCoordination with fire attackCoordination with fire attack


Type of constructionType of construction

Strengths and/or weakness.Strengths and/or weakness.Conventional: Heat hole over area of Conventional: Heat hole over area of involvement.involvement.Lightweight: Vent hole ahead of fire.Lightweight: Vent hole ahead of fire.Time/Manpower constraints. Time/Manpower constraints.


Means of ingress/egressMeans of ingress/egress

LCESLCESIdentify path of travelIdentify path of travelIdentify work areaIdentify work areaTwo means of egressTwo means of egress


““What the ventilation group What the ventilation group needs most and almost never needs most and almost never has is the commodity of timehas is the commodity of time””


To accurately estimate the To accurately estimate the amount of time that a roof can amount of time that a roof can

be considered structurally sound be considered structurally sound the following factors must be the following factors must be

considered:considered:


Time ConsiderationsTime Considerations

Type of constructionType of constructionHow long the fire has been burningHow long the fire has been burningFire severityFire severityYour experienceYour experienceFrequency of trainingFrequency of training


““WeWe’’re Gore Go’’in to the roofin to the roof””!!


Ventilation SizeVentilation Size--UpUp

Type and age of buildingType and age of buildingType of constructionType of constructionLocation and extension of fire and Location and extension of fire and SmokeSmokeType of roofType of roofSpecial HazardsSpecial Hazards


Basic equipment requirementsBasic equipment requirements

Minimum of twoMinimum of two--person teams.person teams.Full safety clothing and SCBA.Full safety clothing and SCBA.Pick head axe and power saw.Pick head axe and power saw.Rubbish hook, pike pole, or other Rubbish hook, pike pole, or other suitable tool.suitable tool.Communication equipment.Communication equipment.


LadderingLadderingConsider the areas that offer strength, routes of Consider the areas that offer strength, routes of travel and no horizontal openings: corners, travel and no horizontal openings: corners, pilasters, hips, etc.pilasters, hips, etc.Minimum of two ladders to a roof, providing a Minimum of two ladders to a roof, providing a primary and alternate way to exit.primary and alternate way to exit.Determine the roof line and its effect on ladder Determine the roof line and its effect on ladder operations. Additional ladders needed?operations. Additional ladders needed?


Ground and Roof LaddersGround and Roof Ladders


Extension LadderExtension Ladder


Ladder OptionsLadder Options


Choose the right tool for the job!Choose the right tool for the job!

2020”” straight is the ladder of choice for flat residentialstraight is the ladder of choice for flat residential

Aerial LadderAerial Ladder

Reading the RoofReading the Roof

What is the size and type of roof?What is the size and type of roof?Is any portion of the roof sagging?Is any portion of the roof sagging?Are there ventilators or smoke vents, and are Are there ventilators or smoke vents, and are they issuing smoke and/or fire?they issuing smoke and/or fire?Is fire showing through the roof?Is fire showing through the roof?Does the roof utilize material which may be Does the roof utilize material which may be difficult to traverse?difficult to traverse?Are additional ladders needed. (steep Are additional ladders needed. (steep pitch/parapets)pitch/parapets)


Diagnostic MethodsDiagnostic Methods

Indicator HoleIndicator HoleCurf cutCurf cut

–– ChainsawChainsaw–– Axe blade/pickAxe blade/pick

Triangle cutTriangle cut–– ChainsawChainsaw–– AxeAxe

Leave a trailLeave a trail


Curf cut using chainsawCurf cut using chainsaw


Apply chain brake and plunge Apply chain brake and plunge saw to remove insulationsaw to remove insulation

Triangle indicator using Triangle indicator using chainsawchainsaw

Triangular indicator hole using Triangular indicator hole using an axean axe

Remove insulation using axe Remove insulation using axe handle or other suitable toolhandle or other suitable tool

PANELIZED WITH PANELIZED WITH INSULATING FOILINSULATING FOIL

Diagnostic MethodsDiagnostic Methods

Determining the type of roofDetermining the type of roof–– The following will assist in determining the The following will assist in determining the

type of roof surface that will support a type of roof surface that will support a ventilation operation:ventilation operation:

PrePre--fire planning.fire planning.Plug cut.Plug cut.Axe bounce.Axe bounce.Inspection cut (45 degree).Inspection cut (45 degree).


PrePre--fire planningfire planning

A valuable aid in determining what types of A valuable aid in determining what types of roofs are in a companyroofs are in a company’’s districts districtVentilation operations are simplified when Ventilation operations are simplified when personnel have prior knowledge of basic personnel have prior knowledge of basic types of roofs and their construction.types of roofs and their construction.


Plug cutPlug cut

A small triangular piece of roofing A small triangular piece of roofing material is removedmaterial is removedReveals the type of roof deckingReveals the type of roof deckingCan determine rafter directionCan determine rafter directionMetal joists are 90Metal joists are 90--degrees to degrees to corrugations in metal deck roofs.corrugations in metal deck roofs.Rafters are 90Rafters are 90--degrees to the grain of degrees to the grain of sheathingsheathing


Axe bounceAxe bounce

Utilized to determine the direction of wood Utilized to determine the direction of wood sheathing.sheathing.Strike the roof at 90Strike the roof at 90--degrees or parallel to degrees or parallel to any exterior wall.any exterior wall.Axe will Axe will ““stickstick”” when parallel to the grain and when parallel to the grain and bounce when 90bounce when 90--degrees to the grain.degrees to the grain.Will also determine the direction of the rafters Will also determine the direction of the rafters underneath the sheathing.underneath the sheathing.


Inspection cutInspection cut

Approximate area to be vented.Approximate area to be vented.Determine size and direction of rafters.Determine size and direction of rafters.Indication of fire intensity in rafter/truss area.Indication of fire intensity in rafter/truss area.45 deg. To outside wall.45 deg. To outside wall.One foot past structural member.One foot past structural member.Complete triangle.Complete triangle.Remove piece over rafter.Remove piece over rafter.


Inspection CutInspection Cut

Inspection hole 45 deg. To outer Inspection hole 45 deg. To outer wall. Continue until rafter is rolledwall. Continue until rafter is rolled

Cut triangular shaped hole, Cut triangular shaped hole, ensure all cuts intersectensure all cuts intersect

Inspection HoleInspection Hole


PART IVPART IV

VENTILATION METHODSVENTILATION METHODS

Heat holeHeat hole

Close to area of involvementClose to area of involvementMost direct path for heat and smokeMost direct path for heat and smokeDangerous procedureDangerous procedureNot recommended with lightweightNot recommended with lightweight

Ventilation MethodsVentilation Methods

Heat Holes over the fire near Heat Holes over the fire near the peakthe peak


Heat hole flat roofHeat hole flat roof


Directional OpeningsDirectional Openings

Strip ventilation opened ahead of the fire.Strip ventilation opened ahead of the fire.Designed to change the horizontal direction Designed to change the horizontal direction or extension of fire, heat and smoke.or extension of fire, heat and smoke.Reduces or curtails horizontal spreadReduces or curtails horizontal spread


WIB STRIP CUT AGAINST WIB STRIP CUT AGAINST CONSTRUCTIONCONSTRUCTION


VENTILATION METHODSVENTILATION METHODS

““Making the CutMaking the Cut””

Center Rafter TechniqueCenter Rafter Technique

Most universal cutting techniqueMost universal cutting techniqueBuilding block of most all vent holesBuilding block of most all vent holesHole size easily increased /extendedHole size easily increased /extendedSections are cut so that they are nailed Sections are cut so that they are nailed to only one rafterto only one rafter


Center RafterCenter Rafter

Center Rafter LouverCenter Rafter Louver

Center rafter holes can easily Center rafter holes can easily be extendedbe extended

Dicing TechniqueDicing Technique

Head cut across several raftersHead cut across several raftersDice cut between raftersDice cut between raftersDecking can be pulled back or louveredDecking can be pulled back or louvered


Multiple rafters can be rolled Multiple rafters can be rolled and marked to allow for dicing and marked to allow for dicing

laterlater

Dice cut between raftersDice cut between rafters

Panels can then be louvered Panels can then be louvered or removedor removed

Multiple center rafter cuts Multiple center rafter cuts allow for various size vent allow for various size vent

holesholes

Louvering TechniqueLouvering Technique

Can be used with most decking materialCan be used with most decking materialAfter cutting deck position as to form After cutting deck position as to form ““louverslouvers”” to facilitate smoke removalto facilitate smoke removal


Panel louvers working from Panel louvers working from purlins against constructionpurlins against construction

““JJ”” HookHook

J hooking with the appropriate tool J hooking with the appropriate tool separates decking from the center separates decking from the center rafterrafterCreates pile of decking at base of holeCreates pile of decking at base of hole


Rubbish hook, pike pole, axe or Rubbish hook, pike pole, axe or other appropriate tool can be usedother appropriate tool can be used

PullPull--back Methodback Method

Can be used on all decking typesCan be used on all decking typesCompletely remove decking from vent Completely remove decking from vent openingopeningPrevent decking from falling into vent Prevent decking from falling into vent holeholePreferred method for heat holesPreferred method for heat holes


““Pull backPull back”” decking to open vent decking to open vent hole and create workable pile of hole and create workable pile of

material material


Always work from primary structural Always work from primary structural membersmembersVariations of a Variations of a ““center raftercenter rafter”” can be can be used on most all roofsused on most all roofs


Panelized roof showing beams Panelized roof showing beams and purlinsand purlins

Panelized schematicPanelized schematic


Panel louverPanel louver

Louver from a beamLouver from a beam


Louver strip from a beamLouver strip from a beam

Special Thanks ToSpecial Thanks To

Fire Station 170Fire Station 170For their dedication and hard workFor their dedication and hard work

Roof Operations Power point Roof Operations Power point Created byCreated by

Firefighter SpecialistFirefighter SpecialistCraig ReedCraig Reed

roof operations - la county firefighters · bowstring arch similar in appearance to ribbed arch and...

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