______ are usually located over larger single-tenant occupancies, which may appear to be part of a row of adjoining stores.
Bowstring truss roofs
Steel-bar joists are spaced __________ apart, in contrast to wooden bowstring trusses, which are ________ apart.
2-6 ft
20 ft
Key factor that allows us to operate within a strip mall with bar-joist roof is:
Steel can be protected against failure by applying a hose stream
Begin attack on fire store with:
2 1/2 in. line
75-80 ft of reach
What size attack lines into exposed stores on either side and begin sweeping cockloft?
1 3/4 in.
2 general classes of taxpayers
New style
Old style
Where do we vent on a bar-joist roof?
Can not cut directly over fire; back away 60 ft or width of 3 average stores from the SAGGING JOISTS to area where hose streams are cooling steel
Heavy fire in metal roof vs wood
Metal = coordinated attack, cooling steel
Wood truss = evacuate (inside and roof)
Size of area when 2 or 3 bar joists fail
10 or 15 ft wide, up to 60 ft long
as opposed to gap 40 ft by 100 or more by single bowstring truss
Commercial buildings differ from residential in several ways that affect crews of FIRST-ALARM engine and ladder companies:
Larger, undivided areas
Fire loading per sq. ft. is heavier
So different tactics!!!
Typical store in taxpayer is: (size)
20 ft wide
75-100 ft deep
10-15 ft ceiling height
(Commercial) One of most beneficial places to spot the pumper is:
This permits:
IN LINE WITH and ACROSS THE STREET from fire store
Use of preconnected master stream or deck gun
To accomplish task of preventing extension and collapse, the key is:
Coordination
Cousin of lightweight truss roof?
Plywood I-beam
Wood-truss roofs behave different than metal roofs. Difference is:
Size and speed of collapse
steel sags and wood trusses snap
One of highest priorities for engine company operations in residential occupancies:
Speed (placing hoseline)
Priority for commercial buildings - Each engine should:
connect to serviceable hydrant
{little need for speed}
Advantage of using one or two lengths of large-diameter hose by first arriving engine versus direct hydrant connection:
allows flexibility in positioning the apparatus
3 advantages of 2 1/2 over smaller lines
Volume and reach.
Personnel efficiency.
Power of stream
Forcible entry difficulties at taxpayer fires are usually greatest:
At the rear.
-at least 1 ladder company should be assigned to rear of all SERIOUS taxpayer fires
Doors almost always open:
Types of locks:
Outward.
Often fox locks and drop-in bars (bolt heads penetrating door).
-may be faster/less damaging breach hole in cement-block wall
Fastest means of gaining entry but most of the time is NOT the best way?
Smashing glass in the door
5 signs of impending backdraft
Heavy smoke. Highly heated Windows. No visible fire. Smoke under pressure w/occasional puffs. Smoke being drawn back into bldg.
Method of forcible entry maintains integrity of window and door glass?
Through-the-lock method
Complete burnout in cellar often because:
- heavy fire loading
- maze-like storage
- absence of quick ventilation
- lack of sprinkler system
Only chance of success for cellar fires:
fast, high volume attack with immediate cutting of vent holes in 1st floor - SOLID TIP, NO FOG.
How much hose when entering a cellar?
Twice the depth of the store PLUS one length.
-always charged before going down cellar stairway
If possible to advance hose deep into cellar: (2)
2nd 2 1/2 in. line at BASE of stairs.
Member with radio at TOP of stairs
Order of attack for cellars (7)
Hand lines to basement with vent.
Not darkened down in 10 minutes, plan new strategy.
Handlines withdrawn, distributor/cellar pipe placed.
After 1-2 minutes, try to advance lines again.
High-ex as many access points as possible.
Master streams flood first floor.
Adjacent cellars to stop extension
Terrazzo, concrete or “mud” tile floors poured on top of wooden floor joists for variety of reasons: (3)
Low maintenance floor surface.
To provide sound or temperature deadening.
Simplify leveling of sagging/uneven floor.
Area to observe if concrete on wooden floor joists in apArtment bldgs:
BAthrooms with tile floors
Concrete on wooden floor joist in prIvate dwellings:
Tile in bathrooms, kItchens and entrance foyers
Concrete on wooden floor joist in stores:
Front sales areas, terrazzo or tile
One particular occupancy where large concentrations of concrete will ALWAYS be found is in:
Self-service laundries.
High torque, bolted down to 12 in. concrete slab.
-properly supported on reinforced concrete pillars
-has been found entirely dependent on wood joists
Concrete floors, most important action to take:
Identify masonry floor supported by wood joists or unprotected steel beams.
-best time = bldg inspections or prefire surveys
Masonry flooring.
Fire-resistive construction -
required for buildings (height):
Indicates what type of concrete:
OVER 75 ft.
Reinforced
Masonry flooring. If size-up indicates ordinary (class 3) or wood-frame (class 5):
Unreinforced masonry is likely (not concrete)
From ground level for heavy fires in stores, sufficient number of 10 ft hooks to get ceiling down:
Entire DEPTH of store and at least 3 ft wide.
2 or 3 lines in each store to make your stand (1 1/2, 1 3/4, 2 in)
If you don’t see improvement fairly soon:
Streams ain’t hitting body of fire OR
Exceptionally heavy body of fire, possibly flammable liquid/gas
100 ft steel beam heated to 1,000F will expand:
9 1/2 in. Lengthwise.
BC 20 ft, 70->1000F = 1.4 in.
Collapse of parapet walls provoked by:
Wind.
Old age
If elevating platform basket is not making any headway:
Then it too must be pulled OUT of the collapse zone
Type of construction being used in newest taxpayers involves ______.
Lightweight wood trusses
Store fire load and life hazard compared to residential
Fire load-higher than residential.
Life hazard-lower than residential.
_______firefighters killed per incident in commercial occupancies vs residential
4 times as many
Any multi-store commercial structure described previously that is built of Class 3 ordinary construction.
Can be one or two stories.
Traditional wood roof or metal deck roof
Taxpayer
Class 2 noncombustible construction.
Typically built without cellars or basements.
Often call strip malls
Newer style taxpayer
Older taxpayer roofs (4)
Standard flat.
Inverted roof.
Metal deck on bar joists.
Bowstring truss
Change in tactics warranted if steel plating encountered (potential backdraft)
Small triangular opening in gate.
Insert 2 1/2 in. fog at 15-30 degree fog (power cone).
Direct upward.
Operate for “several minutes”
How many members with 2 1/2 in. line?
1-get water going.
2-able to advance.
3-can be maneuvered
Taxpayers fires provide one of the greatest uses for ________, if used correctly.
Aerial platforms .
platform on sidewalk, highly mobile 1,000 gpm plus master stream
Traditional tactics for cockloft fires
Hoselines in exposed stores. Pulling ceilings ahead of fire (skip several stores to get ahead). Sweeping cockloft. -6 or more personnel for ceilings -Equal number for hoselines
To get to cockloft on older stores may be able to ______ and newer stores may have ___________.
Remove advertising signs along front parapet (aerial).
All-metal overhanging soffit (circular saw from basket).
Parapets are often _________________ with the result that once one part falls, the rest of the parapet may go with it.
Given a lot of lateral reinforcement
When serious fire involves cockloft of taxpayer or is blowing out the display windows, __________________.
The entire sidewalk on all frontages should be considered within the collapse zone.
Newest taxpayers involve __________.
Lightweight wood trusses as roof and/or floor supports
When PERSONNEL permits, one tactic that works well is to have a ______________ follow the 2 1/2 in. lines, washing down areas the first hose missed.
Third medium-size (1 1/2, 1 3/4 or 2 in)
Cockloft fires.
Following factors compound fast fire spread (3)
Exposing cockloft due to multiple suspended ceilings.
Potential for backdraft within ceiling space.
Difficulty locating seat of fire when smoke is showing in several stores
To avoid pulling entire ceiling, probe with a hook until you find the roof boards. Hollow sound means ______ and solid sound means ______.
Hollow sound = ceiling.
Solid sound = roof
In cases where it is impractical or physically impossible to open the ceiling, ________________.
Send the distributors and cellar pipes up to the roof and insert them into the cockloft from above.
One of the key ingredients to a successful operation in using a master stream to blast through the ceilings at ground level is to ____________.
Maintain as high a nozzle pressure as possible through a solid tip.
An additional consideration when dealing with I-beams is their potential to ___________.
Push through solid walls
To make concrete and masonry useful for applications like floors, which result in _______ loads in the slab, requires some method of resisting such loads. In modern construction, ______, _____, and ________ are stretched within the form, then wet concrete is poured around them.
Tensile.
Steel rods, cables or beams
When checking ceiling with TIC, it can’t see through the multiple hung ceilings. You’ll have to do this with a pike pole, every ______.
8-10 ft.