can metal cornices be removed
they can be removed to provide access to the cockloft area
what is the most prevalanet type of taxpayer
built from the 1920s into the 1960s
what is uaully the main access to the mezzanine area
via small wooden stairs or just a ladder
majority will not be enclosed and there will be a railing edge
what are the rules for sprinkler protection
1938 code area exceeding 10,000 square feet
1968 code area exceeding 7500 square feet
what is the 2008 code- group m mercantile for the FULL building
area exceeding 12,000 sq ft or combined area on all floors including mezzanine exceeds 24,000
storage of merchandise is in high piled racks
what is the 2008 code- group m mercantile for occupancy within building
area exceeding 7500 sq fr or area of any size located 3 stories above grade or an area size located in a high rise building OR area of any size contains an unexposed stair or escalator connecting 2 of more floors
what size is a cockloft generally
can vary in height from 4 inches to more than six feet
roof hoist may be supported at what size intervals
approx 20 foot intervals
bottom chords of many bowstring trusses have inadequate
tensile strength
bow string truss roofs may only support how much
40% of the load they were originally designed to hold
when can an entire truss fail
failure of one truss element can cause failure of the entire truss
when do trusses fail
can occur in early stages of fire
in older truss roof buildings how far are they spaces
10 or 20 feet apart
what kind of truss fail without warning
wood truss
how do you know a steel truss is failing
tend to stretch when losing their strength because of elevated temperatures
how do you know a wood truss is dialing
wood tends to snap
open web steel joist span how long
distances up to 60 feet
open web steel joist may collapse when
only 5 or 10 minutes
due to heat what may happen to stone or block
may spall due to heat or subsequent stream application, reducing load bearing area of wall
how do concrete walls fail
sometimes hinge at ground level and an entire side or rear wall may remain intact and fall out flat
how do brick walls usually fail
usually crumble or break as they fall, but large sections can be projected a good distance due to impacts
what happens to a parapet wall during an uncteolled fire
may be heating the I beams causing there expansion and steadily pushing the parapet outward
how much can a 50 foot long steal beam extend over heat
an average 50 foot steal beam, heated uniformly over its length to 970F will extend approx 4 inches
at 1000F a 100 foot long beam will extend
nine and a half inches in length
steel I beams can reach extreme temperatures in how long
5 to 10 mins
at an uncontrolled fire how long until small beam sections can be heated beyond their strength limits
30 mins for the small beam sections
what happens to a steal I beam that is cooled by hose streams
tests have shown that cooling a steel member will cause it to regain strength and load carrying ability and under normal circumstances there should be no hesitation in cooling them
at 1100 degrees F what will happen to cast iron
it will lose 58% of its original strength
if cast iron is cooled by a hose line what happens
it contracts disproportionately leading to potential failure
can the strength lost on cast iron be regained
NEVER
a cast iron collumn unable to move will do what
Crack
cast iron columns on avg fail when
in about 30 mins in fire test
what are most common types of floors for taxpayers
toungue and groove boards or plywood supported by wood floor joist
in new type taxpayers what is prevelant
slab construction, concrete floors on ground level with no basement or cellars
what are some contents of cellars
electrical supply entrance points with panel boxes and large amounts of wiring
Gas supply with gas meters and piping
where do most taxpayer fires originate
the rear of the first floor where utilities, storage, and services are located
what happens if overhead doors start down with out fully tensioned springs
they will come down with tremendous force
what remains a major FF factor in taxpayers
the roof system because they are mostly made of bar joists, lightweight steel or flat wood truss
what consideration must be taken in assessing the possibility of a collapse
type of construction
intensity of fire
the time that the structure has been burning
what is prevelant about an impact load
it has a much greater effect than the same weight carrie’s as a static or stationary load
what are some warning signs that will signal a potential collapse
heavy body of fire which has been burning out of control for 20 mins or more (particularly in large open areas)
walls leaking smoke or water
walls or columns out of plumb
unsupported walls
spongy or soft feeling
what is recxomended when encountering fires in smoke shops
stretch 2 1/2 and proceed with caution
consideration should be given to knocking down the fire from the sidewalk area before entry is made
what are the three basic factors necessary for backdraft
combustibles
heat
oxygen
what are some potential waning signs of backdraft
reversal of air
glass windows stained with smoke and pulsating
dense BLack smoke indicates lack of oxygen and large quantities of carbon monoxide gas
Dirty brown, yellow brown, gray yellow smoke
although backdrafts can occur anywhere, what areas are vulnerable
cellar and storage areas
what percentage of space is needed in a room of fire to contain the explosive mixture for explosion
25 percent
what is one of the most effective methods of protecting from backdraft
open the roof or area directly over the fire
this allows hot gases to move upward and away
backdraft explosion can be accompanied but what sound
a roar or whistle of great force
what is an alternative to roof venting for backdraft protection
not as effective is the use of a hose stream
when advancing lines deep into large area or cellars what is advisable
post a lookout at the top of the cellar stair or outside entrance to observe conditions
all horizontal and initial vertical ventilation tactics must be controlled, communicated and coordinated by who at tax payer fires
The ladder company officer
in most cases for taxpayers, where is the high portion of the cockloft
the front of the building
does the standard flat roof of a taxpayer have a pitch
may have little or no pitch
if it does it is front to rear
what is a main ventilation goal in taxpayers
to coordinate the opening of a fire building with the application of water on the fire
what is the recxomended hole size for roof ventilation in TP
8 by 8 where possible
if trenching is being implemented what shall be done with the skylights
leave the returns in place where the skylights are to be used as effective trenching
the immediate vent and cutting of an effective hole calls for what
2 saws and 4 members
when more than one power saw is working on the roof who must supervise
a roof sector supervisor
who can be a roof sector supervisor
chief of company officer
when using. FT 2 tip for a dog pattern the engine company should stand back
4 to 5 feet while operating
use of what 2 things can help clear large areas of smoke heat and CO when natural venting is difficult
fog nozzles and positive pressure vent fans
if positive pressure fans used for smoke removal is inneffective, what can be done
the engine officer shall call for the fog tip to be brought up
what direction should the wind be for the most effective and quickest cutting
with the wind at your back
the size and location of roof openings will depend on what
fire conditions, staffing, equipment
how many operations should roof cuts be made
one operation
when removing roof covering what is important
they should be lifted off in one piece if possible
if not the roof covering shall be removed first followed by the roof boards
wood hoist beams usually are spaced how far apart
16 inches on center
when cutting the first floor for a cellar fire where shall it be made
near to the windows as possible away from doorways and aisles. the cut should be extended at right angles to the joist
all cuts should be covered by hoselines
what are risk assessment tactics implemented by the IC for bowstring truss roof
CLASS
current structural stability location of fire any knows life hazard size of fire verification of Safe access area
when can members operate on the roof of structural fire with a bowstring truss
Under no circumstances
what is the primary tactical consideration at vacant, large advanced fires, underside of roof fire, attic area of buildings with truss roofs
exterior operations
what shall members utilize from below of fire has involved the truss space
TIC
what is a method of determining if fire entered the truss space
make a triangular cut in the sloping hip section from the safety of a tower ladder bucket
if possible an exterior hose line from what mayb be directed into cuts to extinguish fire
TL basket
what causes a collapse potential of front and rear walls in a building of truss roof systems
hip rafters being pushed in a down and outward fashion
what roof supports are commonly found in newer taxpayers
lightweight open web steal joist
how are open web joist spaced
greater distances apart than standard wood joist
what is the most common kind of decking in newer taxpayers
corrugated steel
in corrugated steel decking l, joist are spaced
4 to 6 feet
on lightweight open web joist what is vertical ventilation limited to
removal of skylights and scuttle covers
which kind of concrete decking spans wide spaces and is vulnerable to moisture
gypsum
gypsum roof operations shall be conducted where
members shall not be committed to roof ops, interior ops shall be conducted from areas of safety
what will give the presence of a gypsum roof
indicated by a white powdery residue during saw ops
what is the width of a trench
at least 3 feet wide ( any direction)
does trenching take the place of vertical holes
no it’s main purpose is to prevent the fire from passing the point at which the cut is made
when starting a trench cut immediate notification to who is mandatory
IC - the roof sector supervisor can start one where he sees the necessity
can trench cuts be used defensively
yes
when should you special call an extra engine and ladder for a fire in a store
when 2 hand lines are operating
when is a second alarm warranted in a taxpayer
cockloft extension
adjoining occupancy
advanced fire in the cellar
a properly positioned tower ladder can cover a building with a frontage of
100 feet
which sides of a taxpayer should be covered with portable ladders
All sides
a minimum of how many portable ladders shall be placed on the front
minimum of 2 portable ladders on the front
what time do the fires cause the most problems and losses in taxpayers
after occupancies are closed
when should the initial lines at taxpayers be 2 1/2
when heavy or medium fire conditions are encountered
when can a hose line be reduced to 1 3/4 at a taxpayer fire
if 2 1/2 not required after the initial attack it can be reduced
can 1 3/4 lines be used in exposures
yes
at a taxpayer cellar fire where should the first engine company stretch
into the occupancy above the fire to prevent vertical extension.
what are the responsibilities of the second engine company in a taxpayer cellar fire
1) assist with the initial line
2) when 1st engine has not supplied the system a second line shall be stretched to do it
3) AFTER supplying the sprinkler system stretch a line to back up the 1st due line
who ensures the sprinkler system is supplied at a taxpayer
third engine company
at a taxpayer store fire where is the 1st line stretched
into the involved store to protect life
where shall the second engine operate at a taxpayer store fire
assist with the first line
supply the system if not done
stretch a line to back up 1st
what is the 1st engine company doing at a cockloft taxpayer fire
stretch a hand line into the most exposed occupancy or building **
if exposures aren’t immediate problem stretch into the store under the fire
what are the responsibilities of the second engine company at a taxpayer cockloft fire
assist the first engine with the initial line.
if staffing permits, stretch a line into another seriously exposed building and operate
may be advisable to skip stores
What is notable about ladder companies cutting gates
may be preferable (not must) to continue down the row of stores opening them all
if there is high heat on the first floor with no visible flame what may be suspected
cellar fire
in taxpayers do you expect to find cellars conforming to first floor layouts
no
when sending members into cellars to shut down utilities who shall be dispatched
two masked equipped members as a team
what are the responsibilities of the 1st due inside team at a cellar fire
forcible entry as required in both store and cellar
search the store for occupants
after communicated and coordinating ventilate the store as necessary. Take our store windows if required and ventilate from the interior where possible
shut down utilities***
what is a main responsibility for the 1st due roof man at a cellar fire
after coordinating with the company officer inside fire area to be vented, provide roof vent of scuttles , etc.
what is the primary position for the 1st arriving TL
in front of the fire building
who shall bring a saw to the roof at a cellar taxpayer fire
the second due roof man if roof requires further opening
most taxpayer fires originate where
in the store occupancy at street level
generally in storage or utility area usually in rear
what is prevelant about ducts in taxpayer
they are often covered with non flammable insulation paper covering which may cause fire extension during operations
what does trenching depend on
size of roof
volume of fire
type of ceiling and height
who shuts the utilities at taxpayers
1st due inside team
if fire extends to the cockloft where shall the chauffer report
to the roof to assist the roof firefighter
what are the tool assignments for the second due roof man in a taxpayer fire
take saw to the roof and assist in ventilation (axe, iron)
what is the tool assignment for the 3rd due ladder companies and additional truck companies at tax payer ops
bring 10 and 12 foot hooks
how do you cut the metal slats of security doors
with the power saw, two cuts are made across the slats to form a triangle with the apex on the TOP
what is the tool assignment for the ov at a taxpayer
mail and halligan
what is prevalent about taxpayers from the 1920 ls and cockloft access
the decorative metal cornice could be removed to provide access
what years are the most prevalent type of taxpayers
1920s to 1960/
firewalls may have been installed for subdivision of the building
buildings after 1960s have what in place of wood beams to support floors and roofs
steel bar joists…combustible material has been reduced
what is prevalent about the height of the mezzanine
height of the ceilings will be below average
the open web joist or steel bar joist prevalent in modern taxpayers is what kind of truss
lightweight pareallel chord truss
what kind of truss is common in older commercial structures
supermarkets, bowling alleys, lumberyards
wooden bowstring truss
for wooden truss with hump like profile, the longer the span the…
higher the bow***
why is snow prevalent to roof operations
it can cause an eccentric off center unbalanced load that can overload on the truss
when heated steel beams are cooled what will happen
it will contract to its original length
what does cooling a steel member do to strength and load carrying capacity
it will help regain its strength and load
will majority of mazzanines be enclosed
NO
if fire has seriously involved a major portion of the cockloft what is to be said about trenching
it is not practical
