Ch. 9: Ventilation Flashcards
(425 cards)
1
Q
Ch. 9: Norman – Ventilation
(NC #1)
Fire attacks buildings, constantly in search of more:
A
Fuel & oxygen
2
Q
Ch. 9: Norman – Ventilation
(NC #2)
Both contestants (fire & FFs) need the same raw material in which to fight – (that raw material is?).
Whoever controls the ___ supply, wins the battle.
A
Oxygen (for both answers)
3
Q
Ch. 9: Norman – Ventilation
(NC #3)
Used properly, ___ it can be the deciding factor in whether a bldg is saved or becomes a smoldering pile of debris:
A
Ventilation
4
Q
Ch. 9: Norman – Ventilation
(NC #4)
Fig. 9-1: Letting the fire go up and out slows ___ and stops fire from ___. Both are good things:
A
- Slows horizontal fire travel,
- Stops it from banking down inside of the bldg.
5
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #5)
Ventilation can be defined as the process of:
A
Removing toxic products of combustion & replacing them with fresh air.
6
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #6)
To Chief Norman, ventilation is an ongoing battle between fire & FFs for:
A
Control of the bldg
7
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #7)
Serious fires that threaten the very existence of a structure demand ___ in order for interior forces to do their job.
A
Total ventilation
8
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #8)
If you don’t let out the ___, they will drive you out of the structure:
A
Products of combustion
9
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #9)
There are 2 main reasons for performing ventilation:
A
- Venting to allow attack teams to enter & operate w/in structure (vent for fire)
- Venting specific area to provide fresh air for breathing & improving visibility while searching (vent for life)
10
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #10)
The universal use of ___ has some people thinking that ventilation is less important than it was in the past just bc FFs can breathe:
A
SCBAs
11
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #11)
(CFPC) – There are 2 problems with this thinking:
A
1st – ignores victims who might be still be in the bldg – they don’t have masks.
2nd – it assumes FF’s masks will always protect them – not always so.
12
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #12)
“Textbook ventilation” creates only ___ that breaking double hung windows does:
A
Half the window opening
13
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #13)
When you are operating in ___ atmospheres, there is no place for glass conservation:
A
IDLH
14
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #14)
The 3rd problem with ineffective ventilation & SCBA use is the buildup of:
A
Heat that results when venting isn’t prompt & effective.
15
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #15)
Heat buildup results in:
A
Flashover
16
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #16)
3rd problem with ineffective ventilation (cont): The mask protects you against smoke, but offers no protection against:
A
Fire
17
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #17)
4th problem with thinking that ventilation is not as critical as it was in the past is that buildings are:
A
Being made tighter and tighter
18
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #18)
The ‘green bldg’ movement & energy conservation efforts will only increase our difficulties. The potential for ___ is increasing with every bit of insulation & window caulking that is applied:
A
Devastating backdraft explosions
19
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #19)
When distinguishing between venting for life and venting for fire, the key factor is:
A
The timing of the ventilation
20
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #20)
When distinguishing between venting for life and venting for fire, the key factor is the timing of the ventilation. VFL should begin (when):
A
VFL – begin as soon as life hazard is recognized.
Ensure venting draws fire away from life hazard.
21
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #21)
Immediate vertical ventilation has saved hundreds of lives by:
A
Preventing mushrooming & drawing fire away from the victims.
22
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #22)
Vertical ventilation should be a primary tactic at most ___ dwellings:
A
Most low-rise, non-fireproof multiple dwellings
23
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #23)
Venting for fire is normally delayed until:
A
Resources are in place for attack
should take place just as line begins attack
24
Q
Ch. 9: Norman – Ventilation
Section: Reasons for Ventilation (NC #24)
VFF – Once an attack has begun, you can order the windows in the fire apartment, ___ to be vented (which ones and why):
A
Windows opposite the hoselines’ advance – to allow the POCs to be blown ahead & thereby speeding advance of the hoselines.
25
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #25)
The venting of windows is called _____ ventilation.
Horizontal ventilation
26
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #26)
Generally, horizontal ventilation for a life hazard must be coupled with:
An immediate rescue effort
27
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #27)
Generally, horizontal ventilation for a life hazard must be coupled with an immediate rescue effort – by either:
* A ff must enter the area & remove the victim -or-
| * A hoseline must be brought in place to protect victim where they are trapped.
28
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #28)
Fig. 9-2: Venting windows can be done to speed ___ or reach ___:
* Speed the hoseline’s advance
| * Reach a victim trapped in the room behind the glass.
29
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #29)
Fig. 9-2 (cont): Venting windows - done to speed hoseline’s attack or reach victim trapped in the room behind the glass. Coordination of this effort with ___ is crucial to success:
Fire attack
30
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #30)
The most important concept to remember when discussing ventilation is that it must be:
Of sufficient volume to win the battle with the fire
31
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #31)
Damage that results from fd efforts should be commensurate with -
* The amount of damage the fire is causing
| * As well as the extent of the life hazard
32
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #32)
Question raised – when should you break a window as opposed to opening it from the inside? A good rule of thumb is to:
Let fire be the guide, not smoke
33
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #33)
CFPC – If you can stand up and manipulate the locking devices, go ahead and:
Open the window
34
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #34)
CFPC - If it (window) seems stuck & you aren’t being subjected to a lot of heat – & if smoke isn’t impending any other operations, you should probably:
Look for another means of venting
35
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #35)
If you are driven back by down by heat when you try to stand up, or if the smoke is severely hindering visibility or manipulating SCBA use – action is:
Glass should be broken when the hoseline is charged.
36
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #36)
If fire is low intensity (food on stove or smoky mattress, etc) – open, don’t break windows. ___ ventilation is often beneficial in moving this cool smoke.
Mechanical ventilation
37
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #37)
In low intensity fire (food on stove, smoky mattress, etc) – open, don’t break windows. Mechanical ventilation is beneficial in moving this cool smoke & it poses few of the dangers present when using ___ during working structure fires.
Fans
38
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #38)
Window venting is the most suitable type of ventilation for most fires in houses & similar size structures that have ___ ratios:
High window-to-room-size ratios
39
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #39)
As a guide/rule of thumb – ‘if you can stand up long enough to manipulate locks, then raise windows. If can’t stand up that high or that long due to heat – take the glass.’ Considerations to make when breaking glass, 1st → have an idea of:
Progress of fire control & search efforts.
40
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #40)
As a guide/rule of thumb – ‘if you can stand up long enough to manipulate locks, then raise windows. If can’t stand up that high or that long due to heat – take the glass.’ 2nd factor to consider when breaking glass is conditions will:
Conditions likely to worsen before they get better
| review/state 2 factors to consider before breaking glass
41
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #41)
Venting not only provides fresh air to trapped victims, but also improves conditions for firefighting, leading to:
Earlier control
42
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #42)
Venting not only provides fresh air to trapped victims, but also improves conditions for firefighting, leading to earlier control. FFs will also be less subject to ___ & ___ if hoselines are operating on the fire.
Disorientation or becoming trapped
43
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #43)
Breaking glass provides ___ as much window-opening area as raising double hung windows:
Twice as much
THIS WAS A TEST QUESTION!
44
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #44)
Breaking glass provides twice as much window-opening area as raising double hung windows. Since these (double hung) are predominant windows in the majority of ___ bldgs, ffs must be prepared to break glass if conditions require:
Residential
45
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #45)
FFs must time their ventilation efforts properly.
- Venting too early will allow:
- While delaying ventilation will subject:
- Too early: allows fire to extend.
| - Delaying: subjects FFs to unnecessary punishment from heat.
46
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #46)
Generally, venting for life should take place just as:
The hoseline begins its attack
| best coordination is via radio
47
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #47)
(CFPC) – M of attack team should give the word to take the windows just as the nozzle team opens the nozzle. If radios aren’t available, person creating the vent should wait until:
The sights & sounds of hose-stream operation (stream & fire knockdown) confirm that the line has indeed begun operating.
48
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #48)
A problem the fire service is just beginning to recognize involves the construction of newer types of windows on the market. What makes them different from most older models are:
The materials used, especially Thermoplane glass & the style of construction.
49
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #49)
Newer windows on the market – In tightly sealed areas, windows are typically glazed with ___ energy efficient glass:
Double or triple pane energy efficient glass.
50
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #50)
Windows glazed w/ double or triple pane energy efficient glass - must make exception to sequence of ventilating as the attack begins. In this case, a sudden admission of ___ as the attack crew enters can have catastrophic results:
Oxygen
| extreme fire growth or even backdraft is possible
51
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #51)
When you encounter energy efficient windows, undertake venting (when and while):
Undertake window venting asap - while attack team is in safe area (preferably behind closed door)
52
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #52)
(CFPC) – If not possible to, it may be desirable to:
Delay venting until the hose stream has thoroughly cooled fire area
(otherwise we risk FFs being caught in flashovers)
53
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #53)
Usual classic warning signs of flashover include:
* Open flame growing progressively to the ceiling, then rolling along ceiling.
* High heat & smoke.
* Rapid ignition of surrounding combustibles.
54
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #54)
Today’s energy conservation practices can turn occupancies into kilns, where a slow-burning fire can:
Dry out all of the combustibles in the area.
55
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #55)
If the rate of burning reaches ___ stage, then the entire area is ready to flashover:
Free burning stage
| wasn’t as common in older bldgs
56
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #56)
Other factors that energy efficient windows introduce are (4):
* The difficulty in venting them with a __:
* Difficulty of clearing the entire sash area for:
* Hose stream.
* Entry or escape.
57
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #58)
The inability to clear the horizontal sash in the middle of a double hung window is possibly a more dangerous effect. Many of the new windows are ___ construction that bends & bounces back into shape when struck by a tool:
Rolled vinyl construction
| more effort is involved in removing vinyl sashes than is required for wooden ones
58
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #59)
Other styles of (new windows) – are ___ framed and may defy even repeated blows with an axe.
Aluminum frame windows
59
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #60)
After the placement of the initial attack hoseline and the designation of an interior search team, quite possibly the next most crucial position to be covered is:
The outside ventilation (OV) team.
| note: this context is in the ‘newer windows’ section of the chapter
60
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #61)
The OV (outside ventilation) team is responsible for (4):
1. Immediate exterior survey of structure
2. Locating victims
3. Locating seat of fire
4. Creating FF escape routes
61
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #62)
Another potentially life-threatening development regarding window ventilation has developed as a result of ___ in recent years:
Hurricane damage
62
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #63)
Research has shown that much of the damage from a hurricane results when windows are broken by:
Flying debris – thus allowing the wind to enter the inside of the structure and push the roof off from underneath.
63
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #64)
(CFPC) – As a result, several bldg codes, predominantly in ___ areas, are starting to specify window glazing that is resistant to impact:
Hurricane-prone coastal areas such as Florida.
64
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #65)
(CFPC) – the result is windows that are absolutely impossible to vent using conventional methods. They are tested to resist a ___ w/out penetration:
9 lb 2x4 shot out of a canon at 34 mph
| our common tools will result in cracking, but no effective ventilation
65
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #66)
There are several manufacturers & different formulations of glazing, depending on:
Size of the opening to be enclosed & desired strength.
66
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #67)
(New e/e windows) – Some materials consist if up to 3 layers of plastic sandwiched between outer layers of glass. A very common formulation involves glass sandwiched around a:
Polycorbonate plastic such as Lexan
| Image illustration is Fig. 9-3, on next card
67
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #68)
Fig. 9-3: High-security, impact-resistant glazings such as glass-Lexan-glass sandwiches are increasingly popular & require special tools & techniques to ventilate for rescue or escape. FFs operating in areas where these are common must realize:
That escape may not be possible through such a window.
68
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #69)
Sandwich windows – extremely strong & are also finding use for the security they offer. The sandwiched effect of the 2 materials is far superior to either individually. The sandwich is superior to glass in resistance to breaking, and the outer glass also serves to protect the plastic, which in previous single use could be destroyed by:
Being coated with lighter fluid and then ignited.
| in NYC, used in public housing developments in areas of high vandalism
69
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #70)
(Sandwiched glass) – Striking this glass with our common tools will result in ___, but no ___:
Result in cracking, but no effective ventilation.
70
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #71)
(Sandwiched windows) – The best way to breach the glazing is to use a __, if available:
Circular saw with a standard carbide-tipped (wood cutting) blade if available.
71
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #72)
Sandwiched windows – breaching glazing w/ carbide-tipped blade on circular saw; extra precautions are necessary in this operation due to effect blade has on material. That effect is:
Very fine chips & dust from both dust and plastic will be thrown off.
(Everyone in vicinity of operation should be on air from SCBA to avoid inhaling this mixture as well as to keep it out of their eyes)
72
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #73)
Sandwiched windows – if saw if not available, its possible to cut through this type of window using the blade of an axe. More difficult and cutting procedure is __ (2):
But avoid ___:
* Use short chopping strokes,
* Cutting nearly perpendicular to the pane
• Avoid striking the glazing at 90 degree angle.
73
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #74)
Sandwiched windows – when cutting through using the blade of an axe → the last thing you want to do is:
Drive the head of the axe completely through the glass – bc it gets stuck easily and is difficult to pull back through.
74
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #75)
If (saw or axe) methods unsuccessful, may be possible to create openings through walls w/ less difficult - be prepared for more than you expect. In many places where impact-resistant glazing has been installed, ___ may have been used for much the same reasons:
Impact-resistant wall materials
(there’s even impact resistant wallboard available that is Lexan backed – making breaching such a partition wall nearly impossible with standard hand tools)
75
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #76)
Areas that routinely encounter such security or hurricane precautions should assign an OV team early in the incident to:
Locate & clear all life-threatening obstructions.
76
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #77)
(CPFC) – OV Team will require which tools ___:
And for wood-frame bldgs, a ___ would also be beneficial:
* Circular saw w/ carbide tip blade, in addition to tools they already carry.
* Carbide-tipped chain saw.
77
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #78)
Factors that influence choice of vertical or horizontal ventilation or both include:
* Size & location of fire,
* Construction of bldg,
* Available staffing, and -
* The effects of the weather, particularly the wind.
78
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #79)
___ ventilation is often preferred at minor to moderate fires:
Horizontal
79
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #80)
A mattress fire will produce large quantities of smoke, but there’s rarely a need for mechanical ventilation. In fact, vertical ventilation may not be very effective, since:
The low heat levels of an early stage mattress fire don’t make the smoke rise very rapidly.
80
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #81)
Horizontal ventilation is often easier & faster to perform than vertical ventilation because it takes advantage of __. In addition, h/v can be performed from:
* Man-made openings (doors, windows)
| * Ground level or from 1 man portable ladder
81
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #82)
Vertical ventilation usually requires ___, to get to the roof:
A longer ladder, and thus more personnel
82
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #83)
In most cases, horizontal ventilation is less costly to repair than vertical ventilation unless there is a:
Preexisting opening such as a skylight at the roof level.
83
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #84)
Certain roofs can indicate the type of ventilation required. Peaked roofs on many private homes, are usually much more easily vented by ___, than by cutting the roof itself:
Smashing windows in gable ends or dormers.
84
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #85)
Flat roofs of ___ construction would defy all but the strongest venting efforts:
Poured concrete
85
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #87)
Vertical ventilation is often a deciding factor in whether the fire is stopped or continues to expand. Burning materials produce ___, which take up huge volumes of space, 100s of times the volume of the original burning material.
Hot gas
86
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #88)
Burning materials produce hot gas, which take up huge volumes of space, 100s of times the volume of the original burning material. This gas, naturally tries to rise. When it cannot, it:
Spreads out horizontally
| Creates measurable pressure that will push through smallest opening
87
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #89)
(CFPC)¬ - If you can create a way for mushrooming to go up & out of bldg, gas will:
Take large a part of heat energy with it, rather than allowing it to remain inside.
88
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #90)
Horizontal venting of large quantities of hot gas is hindered by fact that – as it flows along, under the ceiling toward open window – it (does what)?
Radiates heat in all directions.
| This means combustibles are being preheated & ff’s heated as well
89
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #91)
Benefits of vertical ventilation include horizontal fire extension is slowed dramatically. In addition, visibility & heat conditions improve rapidly as:
Fresh air is drawn at lower levels to replace the hot gas that is exiting out of the top.
90
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #92)
Not every fire demands, or even allows for vertical ventilation. 2 examples of fires that probably won’t benefit from opening the roof:
* Relatively minor fires with little heat buildup.
| * Fires in lower portions of structures, remote from vertical openings.
91
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #93)
(Examples of fires) where will be greatly aided by vertical ventilation:
* Attics
* Cocklofts
* Floor directly below fire floor
92
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #94)
Fig. 9-6: Fire venting through the opening in a roof is a good sign. It means:
The spread of fire under the roof is being slowed.
93
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #95)
Natural ventilation – by heating up products of combustion, fire has made its by-products mobile. All we have to do is open doors, windows or skylights and the smoke readily pours out. This is called natural ventilation since it is based on ___:
It is based on the natural action of heated gas.
94
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #96)
Occasionally, the natural process is insufficient to remove ___ rapidly enough to allow FFs to finish their tasks without difficulty:
Products of combustion
95
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #97)
At times, smoke may be so cool that natural ventilation won’t work. Smoke will hang down low, keeping CO & HCN w/ it. Or fully developed fire knocked by sprinklers but not fully extinguished. Both cases are candidates for what type of vent:
Mechanical vent - to move gas that wouldn’t otherwise be displaced easily.
96
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #98)
Depending on resources available & fire situation, mechanical ventilation can involve:
* Hoselines
* Portable fans
* Bldg vent systems
97
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #99)
Venting can be done either by:
Both methods accomplish the objective of:
* Sucking contaminated air out or
* Blowing fresh air in.
• Removing all of the contaminated air & replacing it with fresh air.
98
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #100)
Ventilation using a ___ or ___ is one of the earliest and simplest means of mechanical ventilation:
Fog or spray stream
99
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #101)
Ventilation using a fog or spray stream is 1 of the earliest & simplest means of mechanical ventilation. It is by far the least demanding in terms of:
Personnel
100
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #102)
Ventilation using a fog or spray stream is 1 of the earliest & simplest means of mechanical ventilation. It is by far the least demanding in terms of personnel. This method relies on the fact that:
A spray of water entrains air with it, carrying the air out in a stream
101
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #103)
Mechanical Ventilation – Fog or Spray Stream: Several factors that affect how much air, thus smoke a stream can move:
* Volume of water flowing
* Velocity of stream
* Geometry of the opening and stream
102
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #104)
Mech. Vent; Fog/Spray Stream: Factors that affect how much air, thus smoke a stream can move → 1st – volume of water flowing, since each tiny water droplet brings along a limited amount of:
Air
The more water flowing → the more air is moved.
103
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #105)
Mech. Vent; Fog/Spray Stream: Factors that affect how much air, thus smoke a stream can move → 2nd is velocity of the stream, which is a function of:
The pattern of the stream & the nozzle flowing pressure.
| the higher the NP, the more air that is moved
104
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #106)
M-Vent; Fog/Spray Stream: Factors that affect how much air - thus smoke a stream can move; 2nd (cont): The pattern that moves the most air from an area is 1 that is ___. And degree is:
* 1 that is tight enough to move the stream & gas out of the area, yet wide enough to entrain large amounts of air.
* Generally this is in the range of about 30 degree fog pattern.
105
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #107)
Fig. 9-7: The use of a fog pattern to assist ventilation is a very useful technique. It can also be performed with a solid-tip nozzle by only:
Opening the shutoff partway
106
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #108)
Fig. 9-7 (cont): Fog pattern to assist in ventilation:
* ___ optimum angle of pattern:
* Nozzle distance to window ___ optimum:
* 30 – 35 degrees
* 6-8 ft
(Higher = better NP)
(Gallonage higher = greater air flow)
107
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #109)
M-Vent; Fog/Spray Stream: Factors that affect how much air, thus smoke a stream can move → 3rd factor is geometry of the opening & stream. By standing ___ back from the window/door & adjusting the pattern to cover just the opening, you create a:
6 – 8’
Venturi effect – which will add to the efficiency of the stream itself.
108
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #110)
(CFPC) – At times, 6-8’ positioning won’t be possible/practical. In case of a well-involved comm. area of md size, to get 6-8’ away from the window may mean you have to pass a lot of smoldering material. When you begin your ventilation efforts, fresh air drawn towards nozzle can cause:
The smoldering material to burst back into flame, drawing all the heat smoke past the nozzle team.
109
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #111)
(CFPC) – In this case, its better to give up some efficiency & remain farther back, using a ___ to reach the door:
Narrower stream
110
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #112)
Mechanical Ventilation with a fog or spray stream → If practical, keep the fire between ___ & ___ until you are sure there is little danger from a fanned rekindle.
Nozzle & the vent point
| This NC ties into previous cards
111
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #113)
Mech. Vent w/ Fog: Danger of fanning into life a smoldering fire is possible w/ all types of mechanical vent. FF’s on line can darken such fire down. Since/bc:
The volume of air moved is generally much larger & occurs faster than if you rely on natural ventilation.
112
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #115)
Mech. Vent w/ Fog: Of course there are drawbacks to using a hose stream. Areas where this procedure can’t be used include (3):
* Minor fires where h2o damage is concern,
* In areas of poor water supply (drain of using part of avail. water supply to move smoke may mean running short on water for fire control)
* In areas of below freezing temps (if spray will land result in ice/fall hazards)
113
Ch. 9: Norman – Ventilation
Section: Types of Ventilation (NC #116)
Smoke ejectors, blowers, exhaust fans & other portable devices suffer none of the drawbacks of the hoseline except the same problem of a:
Forced draft over smoldering embers
(Problems on such devices can develop regarding availability of power supply, personnel requirements, storage space, whether explosive gas is present, etc – but usually can be overcome)
114
Ch. 9: Norman – Ventilation
Section: Negative Vs. Positive Pressure (NC #117)
___ ventilation offers FFs a great opportunity to channel POCs where we want them to go:
Mechanical
115
Ch. 9: Norman – Ventilation
Section: Negative Vs. Positive Pressure (NC #118)
Various types of smoke removal devices offer choice of modes of operation, either sucking smoke out of bldg or blowing fresh air in. For the 1st 20 years of mechanical ventilation, the most common use was ___ devices:
Exhaust devices, sucking smoke through the mechanism.
116
Ch. 9: Norman – Ventilation
Section: Negative Vs. Positive Pressure (NC #119)
Exhaust devices – suck smoke through the mechanism → proved ineffective. Bc fans never fit an opening correctly – makeshift methods used to block off openings around sides of the unit. Penalty for not doing so resulted in:
Churning
117
Ch. 9: Norman – Ventilation
Section: Negative Vs. Positive Pressure (NC #120)
Churning results when/is:
Results in some air from outside being drawn into the bldg & blown out again through the fan.
118
Ch. 9: Norman – Ventilation
Section: Negative Vs. Positive Pressure (NC #121)
Churning results in some air from outside being drawn into the bldg & blown out again through the fan. This means fan isn’t using all of its capacity to move smoke, bc:
Some percentage is wasted moving clean air outside.
119
Ch. 9: Norman – Ventilation
Section: Negative Vs. Positive Pressure (NC #122)
Other problems resulting from exhaust systems – debris, curtains, etc being drawn against the:
Intake screen – thus blocking the flow
120
Ch. 9: Norman – Ventilation
Section: Negative Vs. Positive Pressure (NC #123)
Another disadvantage is the location of a negative pressure fan, hanging up or near doorways used by personnel. Bc they blow outward, combustible gases are:
Drawn across the motor.
| Are of explosion proof design when leave factory, but don’t count on it
121
Ch. 9: Norman – Ventilation
Section: Negative Vs. Positive Pressure (NC #124)
Blowing fresh air into the structure – the idea was originally tested as a way of reducing:
Stack effect
122
Ch. 9: Norman – Ventilation
Section: Negative Vs. Positive Pressure (NC #125)
Stack effect, that is the drawing of:
Heat & smoke toward staircases, and thus the point of attack in high-rise fires
123
Ch. 9: Norman – Ventilation
Section: Negative Vs. Positive Pressure (NC #126)
Experimentation has proved that by putting a positive pressure in a stairwell, the ___ can be reversed:
Flow of heated gases – enabling attack crews to gain a foothold on the fire floor.
LAFD has expanded on these experiments.
124
Ch. 9: Norman – Ventilation
Section: Advantages of Positive Pressure Ventilation (NC #127)
PPV has decided advantages of NPV in certain respects, the first is:
Efficiency
125
Ch. 9: Norman – Ventilation
Section: Advantages of Positive Pressure Ventilation (NC #128)
With PPV, the fan is set up (where) in regards to the desired opening:
Outside of the structure, 8 – 12’ away from desired opening.
Airstream from fan aimed to fully cover the opening. Larger doors at comm. structures may require several fans.
126
Ch. 9: Norman – Ventilation
Section: Advantages of Positive Pressure Ventilation (NC #129)
PPV – The moving airstream entrains more air along its sides as it flows, acting as a ___ to bring in more air as it passes through the opening.
Venturi effect
127
Ch. 9: Norman – Ventilation
Section: Advantages of Positive Pressure Ventilation (NC #130)
(CFPC) PPV – Venturi effect → The resulting movement of air into the structure pushes ___ ahead of it:
Smoke contaminated air
128
Ch. 9: Norman – Ventilation
Section: Advantages of Positive Pressure Ventilation (NC #131)
PPV → Just as when advancing a fog stream, you must provide a ___ for the gas opposite the entrance to speed the process:
Outlet
129
Ch. 9: Norman – Ventilation
Section: Advantages of Positive Pressure Ventilation (NC #132)
PPV – A fan can move (how much more) the volume of smoke compared to the negative mode, especially if churning occurs:
Almost twice as much
| another way of looking at it – the same job can be done in half the time
130
Ch. 9: Norman – Ventilation
Section: Advantages of Positive Pressure Ventilation (NC #133)
PPV → experiments conducted by LAFD show that the best results can be obtained by (3):
1. Clearing 1 section of the structure at a time by opening windows in room to be cleared.
2. Then move to next room &
3. Closing windows/doors to isolate 1st room.
131
Ch. 9: Norman – Ventilation
Section: Advantages of Positive Pressure Ventilation (NC #134)
Fig. 9-9: Venting a large structure using PPV should proceed in stages. Do not open all simultaneously, or the fan may not be able to:
Fan may not be able to move a sufficient volume of air to pressurize all the openings.
132
Ch. 9: Norman – Ventilation
Section: Advantages of Positive Pressure Ventilation (NC #135)
PPV → In setting up fans, take ___ into account. Work with it rather than against it.
Natural wind
133
Ch. 9: Norman – Ventilation
Section: Advantages of Positive Pressure Ventilation (NC #136)
PPV → In setting up fans, take natural wind into account. Work with it rather than against it. This method works best with which fires:
* Minor to moderate fires, where
| * Smoke (rather than fire) is the greatest difficulty
134
Ch. 9: Norman – Ventilation
Section: Advantages of Positive Pressure Ventilation (NC #137)
With advanced fires that have self vented – the effect of fan’s airstream may be reduced or overpowered by ___ or ___, due to the large # of openings spread around the bldg:
* Fire’s convective currents &
| * Outside air movements.
135
Ch. 9: Norman – Ventilation
Section: Advantages of Positive Pressure Ventilation (NC #138)
Since PPV fans are set back from doorway, they don’t clutter access routes. Types of fires which are prime candidates for PPV:
* Mattresses, stuffed chairs & other extra smoky fires, such as those -
* Partially extinguished by sprinkler systems
136
Ch. 9: Norman – Ventilation
Section: Advantages of Positive Pressure Ventilation (NC #139)
PPV fans also have a ready ability to remove flammable vapors safely. ___ & ___, for example may have collected in areas away from openings:
NG or propane
137
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #140)
PPV has some drawbacks, the most serious being the danger of:
Way to prevent this is to:
Fanning a smoldering fire into a serious conflagration.
Have a charged hoseline in place & ready to operate.
138
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #141)
(CFPC) - If fire is a ___, it may not be possible to expose it & darken it down fast enough to prevent considerable extension.
Concealed space
139
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #142)
Another possible situation involves separate fires in remote areas, as is common in ___ incidents:
Arson
140
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #143)
The effect of blowing fresh air from a fan onto a fire is the same as when it is directed out of a bellows onto a blacksmith’s ___ - the fire intensifies:
Hearth
141
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #144)
PPV → Fan mustn’t be allowed to ___ on the opposite side:
(Continued on next card)
Blow the fire towards any victims or FFs on the opposite side.
142
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #145)
PPV → Fan mustn’t be allowed to blow fire towards any victims or FFs on opposite side. For this reason, PPV must not be used if FFs are entering the bldg from:
Any points other than where the fan is operating.
| Requires coordination if VES is to be employed
143
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #146)
Fig. 9-10: PPV should not be used at the same time entry into a bldg is made from the outside via:
VES.
(Fan can drive POC, including flames to the just vented area – as its designed to, but a victim you are trying to rescue & FF entering will be directly in its path)
144
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #147)
PPV requires coordination between M’s. Personnel should follow proper sequence of opening/closing windows as each room is cleared. If there are many openings in close proximity to ___, smoke filled area may receive little ventilation as fresh air simply re-circulates to the outdoors:
Door being used for PPV
145
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #148)
Coordinate PPV. Follow proper sequence of opening/ closing windows as ea. room is cleared – won’t be effective if don’t. If lots of windows open in close proximity to PPV door – smoke filled area will receive little ventilation bc:
Fresh air supply will re-circulate to outdoors.
146
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #149)
Naturally, in bldgs where there is a suspected life hazard, the principle of venting for life demands that:
Windows be taken out.
147
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #150)
If a FD becomes too infatuated with PPV, they may find that their desire to keep windows in tact will have an adverse effect on:
Any victims inside who need fresh air to survive.
148
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #151)
The fan can also provide fresh air to trapped occupants, but if there is a ___ in their vicinity, there is a risk of any fire between the victims and the fan right at the victims:
Exhaust opening
149
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #152)
A basic tenet for an interior FFs search for a life hazard is to vent as you move, provided:
The fire won’t be extended by venting
150
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #153)
A basic tenet for an interior FFs search for a life hazard is to vent as you move, provided the fire won’t be extended by venting. That is exactly the (same/opposite) ___ pattern desired to make PPV work most effectively:
Opposite
151
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #154)
The decision to use PPV should be made only after considering all of the factors that affect the situation. Before starting the fan, the IC should know the answers to the following: (1st of 7) – Where is ___:
Life hazard, including FFs
152
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #155)
Decision to use PPV - made after considering all factors that affect the situation. Before starting the fan, the IC should know the answers to the following: (2nd of 7) – What is ___ of fire:
What is location & extent of fire? Is it in void spaces?
153
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #156)
Decision to use PPV - made after considering all factors that affect the situation. Before starting the fan, the IC should know the answers to the following: (3rd of 7) – What is status of:
What is status of all hoselines? Are they operating or ready to operate?
154
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #157)
Decision to use PPV - made after considering all factors that affect the situation. Before starting the fan, the IC should know the answers to the following: (4th of 7) – What degree of ___ is present?
What degree of confinement is present? If fire already self-vented, PPV may not be useful.
155
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #158)
Decision to use PPV - made after considering all factors that affect the situation. Before starting the fan, the IC should know the answers to the following: (5th & 6th of 7) – What ___ are available?
What exhaust openings are available or can be created?
What PPE equipment is available? Will power supply create any issues (noise, exhaust fumes) at CP?
156
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #159)
Decision to use PPV - made after considering all factors that affect the situation. Before starting the fan, the IC should know the answers to the following: (7th of 7) – What ___ exists in vicinity of fan?
What environmental factors exist in vicinity of the fan?
| i.e. dust, weeds, powders, etc – materials that may be drawn into fan, impending ops
157
Ch. 9: Norman – Ventilation
Section: Disadvantages of PPV (NC #160)
Decision to use PPV - made after considering all factors that affect the situation. Before starting the fan, the IC should know the answers to the following 7 questions – Review, all start ‘what is’ except #1:
1. Where is life hazard (including FFs)
2. What is location/extent of fire? Voids?
3. Status of hoselines? Operating/ready to?
4. What degree of confinement is present?
5. What exhaust openings avail/can be made?
6. What PPE equipment avail?
7. Environmental factors around fan?
158
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #161)
Once fire achieves headway, it builds up ___ of its own within the structure:
Pressure
159
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #162)
At times, such pressure is substantial & is responsible for creating the advancing flame front through the fire area as additional gas distills from the burning fuel and expands. The natural tendency of if for the heated gas to:
Rise
160
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #163)
The mushroom effect is:
* Natural tendency for heated gas is to rise;
* When restrained from rising →
* It spreads out horizontally & then starts to bank down.
161
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #164)
Ways to prevent horizontal fire spread:
The most effective & efficient way to prevent horizontal fire spread is:
* Build a fire resistive partition,
* Position countering hose stream,
* Let gas continue on its upward journey, where it wants to go – most effective/efficient way
162
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #165)
Preventing horizontal fire spread, most effective/efficient way is to let the gas continue on its upward journey, where it wants to go. This is best accomplished in multistory structures by:
Making an opening directly over any vertical arteries that the fire is exploring.
163
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #166)
(CFPC)¬ – The most common vertical artery is:
Staircase
THIS WAS A TEST QUESTION
164
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #167)
By providing an opening of sufficient size at the top, the fire can continue skyward without:
Extending horizontally
165
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #168)
Sometimes staircases continue past the floor, ending in a bulkhead w/ a door leading to the roof. ___ (complete what) as your 1st action upon reaching the roof:
Open this door (leading to roof) and check inside for trapped occupants.
166
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #169)
FFs should recognize the bldgs where ___ is possible and, in the event of a serious fire, make efforts to open this as soon as possible:
Vertical ventilation
167
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #170)
Many multistory bldgs have a ___ over the staircase:
Skylight
168
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #171)
Fig. 9-12: The skylight over a stairway is a ready-made opening at the highest point of the ___ that is the interior staircase:
The chimney
169
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #172)
Many multistory bldgs have skylight over staircase – by either removing skylight or breaking panes, you can quickly provide ventilation over stair this critical artery. In breaking the skylight, remember:
Other personnel will most likely be ascending stairs.
170
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #173)
(CFPC)¬ – Give members below some warning of falling glass & don’t drop entire housing through the opening. Besides calling out, “I’m taking the skylight” on the radio, 1st:
Break a single pane of glass 1st, and then pause for a few seconds.
(falling glass will signal to members on the stairs, and they can take steps to protect themselves)
171
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #174)
Members in/ascending stairs – positioning should be:
* Keep heads level, looking neither up or down.
* Hug wall as ascending,
* Keeping hands close to their bodies & off the banister.
172
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #175)
The bulkhead door must also be opened to provide additional ventilation, but more importantly to check for:
Any overcome occupants who many have attempted to flee to the roof.
173
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #176)
Fig. 9-13: Venting the ___ & ___ over a stairway will rapidly clear the interior stairs & halls, saving lives of occupants & FFs.
Skylight & door
174
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #177)
By removing the door from the bulkhead, FFs can use it how, to further increase ventilation:
* By leaning door against bulkhead at roughly a 45 degree angle,
* FF can use it as a ramp to help climb/reach top of bulkhead.
* Then remove or break panes of skylight.
175
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #178)
The top of the bulkhead can be ___ feet above the roof level:
8 – 10’
176
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #179)
Door removed/used as a ramp should be secured in place how:
(this will keep door from sliding down wall when FF mounts. FF needs running start)
* Ramp secured by driving claw of halligan into roof at base of the door.
* Turn forked end of halligan parallel to door to get it out of the way.
177
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #180)
Other vertical paths of fire are pipe chases and dumbwaiter shafts. Dumbwaiters are:
* Small, hand-operated mini-elevators
* Common in multistory residential bldgs built in →
* Built in late 1800’s, early 1900’s
* Purpose → to lower tenant trash to basement
* Most not used today – replaced by incinerators & compactors
* Shafts may still be present – fire can extend up.
* May have mini bulkhead at top w/ door & skylight
178
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #181)
2nd most common vertical avenue for fire is:
The pipe chase (stairs is 1st)
179
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #182)
Pipe chases are commonly found behind which walls:
Bathroom & kitchen
180
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #183)
These shafts (pipe chases in kitchens & bathrooms) extend right up to underside of roof boards – where single pipe extends through roof. The single pipe, which extends through the roof, is called?
* Soil pipe
| * (feel soil pipes – heat may indicate if fire is in cockloft or attic)
181
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #184)
By feeling soil pipes for heat, a member can estimate whether or not fire is about to:
Enter the cockloft or attic
182
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #185)
Even if fire appears confined to a lower floor, take immediate steps to fight it on the top floor or in the attic if soil pipe on roof feels hot to the touch – actions are:
* Hoseline must be stretched to top floor,
* Ceilings must be pulled.
* If fire present → open roof.
183
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #186)
Fig. 9-16: Pipe chases provide a vertical highway for fire travel from:
Lower floors up to the cockloft
184
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #187)
Fig. 9-16 (cont): Roof team shall immediately feel soil pipes & other metal objects for heat – notify command if fire suspected in cockloft. Roof team actions:
* Cut around pipe to let fire go straight up,
* While FFs on top floor pull ceiling & operate hoseline for extinguishment.
* Have other FFs check location of the pipe on each floor for extension.
185
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #188)
Due to numerous interconnections with other blind spaces, a serious fire within a bldg’s voids is a threat to structure. Fires in such spaces are often extremely smoky because the ___ available to the fire is limited:
Oxygen available to fire is limited
186
Ch. 9: Norman – Ventilation
Section: Vertical Ventilation – Taking the Lid Off (NC #189)
(CFPC) - FFs will have difficulty locating, opening & attacking these fires bc limited visibility. Answer is ___. This includes:
* Answer is total ventilation.
* Includes – venting all windows & other horizontal openings,
* As well as roof ventilation – particularly over top of vertical voids.
* (anything less → likely that FFs will be unable to remain in position to cut off further fire spread)
187
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #190)
Flat roofs are generally found in larger buildings such as (4 examples):
* Stores
* Factories
* Schools
* Apt. buildings
188
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #191)
In the past, these (flat) roofs were normally stronger than peaked roofs, since they were designed to support greater ____ loads.
Live loads
189
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #192)
Flat roofs in past – were stronger than peaked roofs since designed to support greater live loads. Such roofs still around in older bldgs. (Norman refers to them as) old-style flat roof. 2 styles of old style flat roofs:
* Standard flat roof – main roof joist are at roof level & roof boards nailed to joists
* Inverted roof
190
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #193)
Description of a standard flat roof:
* Main roof joist are at roof level, and
| * Roof boards nailed to joists
191
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #194)
Description of the inverted roof:
* Roof boards are nailed to a framework of 2x4’s, that is →
| * Raised several feet above main roof joists
192
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #195)
Type of roof which has become dominant in roof industry in last 20 years (at least in east & Midwest) is which roof:
The metal deck roof
193
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #198)
Fig. 9-18 (cont): An inverted roof (is or is not) a truss roof:
is NOT
194
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #196)
Fig. 9-17: Standard flat roof has its main roof supports (joists) at roof level, with roof decking nailed directly to joists. Size of joists and size of tongue & groove roof boards:
* Joists → 2” x 10” (16” on center)
* T & G Roof Boards → 1” x 6”
(note: picture on pg. 257)
195
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #197)
Fig, 9-18: An inverted roof has main roof supports (joists) at ceiling level, w/ roof deck raised several feet above the joists of on a wooden ___.
Framework of 2x4s
196
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #199)
Fig. 9-18 (cont) Inverted roof → Size of:
* Main roof joists:
* Uprights:
* Frames:
* Tongue-&-groove roof boards:
* Main roof joists – 2” x 10” (16” on center)
* Uprights – 2” x 4”
* Frames – 2” x 4”
* T & G Roof Boards – 1”x6”
197
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #200)
Old Style Roof Construction: Older flat roofs have wooden beams of (what sizes) as the main support beams:
2 x 10’s or even 3 x 12’s
198
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #201)
Old Style Roof Construction: Older flat roofs have wooden beams of 2 x 10’s or even 3 x 12’s as the main support beams. These are spaced ___ apart, & can carry nearly the same loads as:
* Spaced 16” apart.
| * Can carry same loads as joists below them.
199
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #202)
Old Style Roof Const: Older flat roofs – wooded beams/timbers are limited in length to about how far in between supports:
20’
200
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #203)
Old Style Roof Const: Older flat roofs – wooded beams/timbers are limited in length to about 20’ in between supports, (supports) are most often a ___ or ___:
Most often a masonry bearing wall or a steel I-beam
201
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #204)
Old Style Roof Const: Older flat roofs – Nailed directly to the roof beams is the ___.
Usually this is (size & material):
* Roof decking.
| * 1 x 6 tongue-and-groove planking
202
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #205)
Old Style Roof Const: Older flat roofs – The roof decking (1x6 t&g planking) is covered by:
This covering acts as a:
* Several layers of tar paper.
| * Tar paper acts as moisture barrier.
203
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #206)
Old Style Roof Const: Older flat roofs – On some very old roofs, a thin layer of ___ was also laid on top of the tar paper:
Tin
204
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #207)
Old Style Roof Const: Older flat roofs – On top of the tar paper (moisture barrier), the entire roof surface was then mopped with ___ to seal it:
Hot tar
205
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #208)
Old Style Roof Const: Older flat roofs – On top of the tar paper (moisture barrier), entire roof surface mopped w/ hot tar to seal it. In some cases, gravel was spread over the hot tar to act as:
Retardant to the spread of flames
206
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #209)
Old Style Roof Const: Older flat roofs – This style has a limited life span of about:
20 – 30 years
207
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #210)
Old Style Roof Const: Older flat roofs – Life span of about 20 – 30 years, and several such layers be found in very old bldgs, making the tar paper up to ___ thick:
3 – 4”
208
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #225)
Fig. 9-20 & 21: Roof team venting top floor windows in fire area w/ halligan & light rope. Procedure (5 Steps):
1. Lower tool to appropriate length 1st, to measure the rope.
2. Grasp rope tightly at measured point.
3. Pull rest of rope back up.
4. Throw halligan straight out – hang on to rope tightly.
5. Rope acts as pendulum - pull rope into window.
209
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #211)
Old Style Roof Const: Older flat roofs - Generally before there’s any danger of the supporting joists succumbing to fire, ___ will have burned through:
* Roof boards (1x6) will have burned through 1st.
| * (Providing warning to FFs to probe in front of them w/ a tool).
210
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #212)
Old Style Roof Const: T or F → The catastrophic roof failure of old-style roofs is not a concern?
True – NOT a concern
| note: fig. 9-19 indicates a standard flat roof is substantial roof, w/ 1x6 boards nailed to the 2x12 joists,
211
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #213)
Old Style Roof Const: Old-style construction with exposed joists can be found in older bldgs such as ___. Where ___ aren’t the primary concerns:
* Garages & warehouses,
| * Where heating & appearance aren’t primary concerns.
212
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #214)
Old Style Roof Const: For occupancy types such as stores, schools & apts – exposed joist unacceptable both for reasons of:
* Aesthetics &
| * Energy Conservation
213
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #215)
Old Style Roof Const: For occupancy types such as stores, schools & apts – exposed joist unacceptable both for reasons of aesthetics & energy conservation. In such cases, ___ has typically been added:
* Ceiling has typically been added.
* (Usually wooden framework,
* Suspended several feet from below the roof from light wooden hangers).
214
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #216)
Old Style Roof Const: (CFPC) – A void space known as a ___ is thus created between the ceiling and the roof boards:
Cockloft
215
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #217)
Old Style Roof Const: Cocklofts serve as insulator from sun’s heat in the summer & the winter’s cold. Fire in either the cockloft or on the occupied floor may be directly vented by:
Cutting a hole directly above fire & pushing down the ceiling
(this action critical one fire has entered the concealed space, as there is no other means of venting this area)
216
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #218)
Old Style Roof Const: A working fire on top flr of any large area flat roof bldg requires immediate commitment of preferably an officer exp. in roof ventilation w/ at least 4 ff’s equipped with:
* 2 power saws
* 2 – 6’ or 8’ hooks (10’ for larger bldg as cockloft may be 5’ deep)
* Halligan & Axe
* Radio
* (access roof by aerial or ladder – never interior stairs)
217
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #219)
Old Style Roof Const: Roof team; Immediately upon reaching roof (via ladder or platform, never through interior stairs), the members should:
* Vent any vertical shafts they find – such as bulkheads & skylights.
* Simultaneously, a M can lean over parapet & vent top-floor windows in fire area with a hook or halligan clipped to a short rope.
218
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #220)
Old Style Roof Const: Fig. 9-20: For top floor fires, the roof team should ___ to assist the interior operations:
Vent top floor windows
219
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #221)
Old Style Roof Const: Roof Team; Be sure when venting (top floor) windows in the fire area that:
Wind won’t be blowing inward & fanning flames.
(A member on the roof can easily evaluate the direction of the wind).
220
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #222)
Old Style Roof Const: Roof Team; After ___, the members can get involved in the more time-consuming operation of cutting open the roof:
After the initial ventilation of stairs & windows.
221
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #223)
(CFPC) Old Style Roof Const: Roof Team; If you perform these operations in reverse you’ll likely delay fire control by:
Hindering advancement of hoseline
222
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #224)
Old Style Roof Const: For years, firefighting texts have advocated that the proper size hole for a fire in a large-area flat roof structure is:
8’ x 8’
223
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #226)
Old Style Roof Const: 1st step in making any ventilation opening is to:
* Locate the proper site –
| * Usually as close to directly over fire as is safe.
224
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #227)
Old Style Roof Const: The ___is most often determined by observing its condition, either as members make their way to the roof or once they arrive there:
Seat of the fire
225
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #228)
(CFPC) Old Style Roof Const: Fire venting out of a window is a good indicator, whereas smoke may not be as reliable. Other means of locating the proper site include:
* Cmmu w/ interior forces by radio
* Feeling soil pipes
* Observe surface of roof for bubbles and steam
* By means of examination holes
226
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #229)
Old Style Roof Const: Examination holes are:
Small, rapidly made penetrations through the roof to look for fire.
227
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #230)
Old Style Roof Const: Examination holes -2 types are commonly & efficiently made with a power saw:
* Triangular opening -or-
| * Short, narrow slit that’s only the width of the blade.
228
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #231)
Old Style Roof Const: Examination hole that is a – short, narrow slit that is only the width of the blade or chain is called:
Keft cut
229
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #232)
Old Style Roof Const: The ___ cut is the simplest, fastest type of examination hole cut possible:
Kerf cut
THIS WAS A TEST QUESTION
230
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #233)
Old Style Roof Const: Kerf is simplest, fastest exam hole possible. And is easily repaired if fire doesn’t severely damage roof. Simply made by plunging saw through roof & then pulling out. Size of cut made is:
¼” wide x 10” long
231
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #234)
Old Style Roof Const: Kerf cut; quick but not a positive indicator of fire bc opening is narrow –doesn’t allow you to view areas on either side. Fire directly below will be visible, but not fire on either sides esp. in daylight. Alternate method:
* Make triangular shaped opening where you suspect you may find fire.
* More time consuming examination cut.
232
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #235)
Old Style Roof Const: Triangular opening examination cut. Procedure is:
* Plunge saw through roof 3 times so edges overlap.
* Results 8” – 10” triangle will readily fall into structure unless you cut →
* Over a joist.
233
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #236)
Fig. 9-22: Inspection hole can be a triangular opening used to quickly determine if fire is present on cockloft below. Be sure corners overlap by ___: More if ___ is thicker:
2 – 3”
| more if tar paper is thicker
234
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #237)
Old Style Roof Const: Triangular examination cut → This type of cut improves visibility to the sides, and the hole may be used to ___, to knock down fire if handlines are unavailable for advance:
Inserting a nozzle or pipe, such as a Bresnan distributor
235
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #238)
Old Style Roof Const: Once chosen proper site, plan the cut & make all M’s in vicinity aware of the operation. ___ of any type are deadly weapons under wrong conditions:
Power saws
236
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #239)
Old Style Roof Const: Once chosen proper site, plan the cut & make all M’s in vicinity aware of the operation. The 1st item to consider is:
Means of escape from the roof - if things go badly.
237
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #240)
Old Style Roof Const: Once chosen proper site, plan the cut & make all M’s in vicinity aware of the operation. The 1st item to consider is means of escape from the roof, if things go badly. Make the cut so as not to be between:
The members & their means of escape, especially on smaller roofs.
238
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #241)
Fig. 9-23: Never make roof ventilation holes where they will cut off your means of escape. Always have a:
2nd way off of a roof
239
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #242)
Old Style Roof Const: Fire venting out of a hole can seal off a relatively large path. Be sure you have at least 2 ways off each roof. If there’s only one, make sure somebody:
Arranges another ladder placed where members can use it – if 1st route gets cut off by fire.
240
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #243)
Old Style Roof Const: The 2nd consideration when positioning for a cut on the roof is:
* Wind direction
| * (1st – egress)
241
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #244)
Old Style Roof Const: 2nd concern when positioning the cut is wind direction. This may be the 1st concern in some cases, since the wind might be:
Blowing the fire or smoke in a way that would cut off your retreat.
242
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #245)
Old Style Roof Const: Roof Team; Locate the cut so that if the fire vents out, it won’t endanger:
Nearby exposures
243
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #246)
Old Style Roof Const: In case further expansion of the hole is necessary to relieve conditions below, make initial cut so that it won’t unduly:
Hinder further cutting.
244
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #247)
Old Style Roof Const: Roof Tm; Sequence of cuts need to produce an 8’ x 8’ opening must be logically planned so that members making the later parts of the hole won’t be:
* Downwind from earlier segments, where →
| * Heat, smoke, fire may prevent from completion of task.
245
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #248)
Old Style Roof Const: Roof Team; The cut should never be laid out so that a member, in doing further work, must step on:
A portion of the roof that has already been compromised
246
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #249)
Old Style Roof Const: Roof Tm; The actual mechanics of making the proper sequence of cuts requires saw operators to be capable of:
* Cutting both left/right handed.
| * So as to ensure they are standing on solid roofing at all times
247
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #250)
Old Style Roof Const: Roof Tm; Locate the supporting roof joists by:
Sounding them with an axe or other tool
248
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #251)
Old Style Roof Const: Locate supporting roof joists by sounding them w/ an axe or tool. Strike the surface of the roof w/ blunt end of tool held tightly in your hand. When tool lands in the space between the joist, (what will happen):
Tool will have a slight bounce to it
249
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #252)
(CFPC) Old Style Roof Const: Roof Tm; When tool lands above the joists, it will:
Strike solidly, with little or no bounce
250
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #253)
Old Style Roof Const: Roof Cut; The cut should be close to the (inside or outside) ___ of selected joists:
The inside of selected joists
251
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #254)
Old Style Roof Const: Roof Cut; Make as close to the inside of selected joists – this accomplishes 2 things:
* Provides as large opening as poss. &
| * Those who are pulling roofing will have to pull against as few nails as poss.
252
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #255)
Old Style Roof Const: Roof Cut; Saw operator needs to keep in mind the process of ___ while making the incisions:
Pulling the cut open
253
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #256)
Old Style Roof Const: Roof Cut; Saw operator – keep in mind process of pulling the cut open while making the incisions. The hole should be subdivided into pieces of a manageable size, generally ___.
* 4 x 4-ft.
| * Since it’s virtually impossible to pull up an 8x8-ft piece of roofing.
254
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #257)
Old Style Roof Const: Roof Cut; Saw operator should also make sufficient knockout holes which are:
* Triangular openings at corners of each section.
* Designed to fall or be pushed down.
* Similar to inspection holes.
* Allow ff’s to insert hooks below the roofline for pulling or prying - Nearly impossible to get a purchase on roof w/out them.
255
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #258)
Fig. 9-24: Plan the sequence of roof cuts, taking (3) into account:
* Escape routes
* Wind
* Fire location
256
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #259)
Fig. 9-24 (cont): A standard 4’ x 4’ roof can be extended to produce an 8’ x 8’ opening, if planned properly. Order of cuts for 4’ x 4’ hole.
(Drawn from page 261)
257
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #260)
Fig. 9-24 (cont): A standard 4’ x 4’ roof can be extended to produce an 8’ x 8’ opening, if planned properly. Order of cuts for 8’ x 8’ hole.
(Drawn from page 261)
258
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #261)
Old Style Roof Const: Roof Cut; Saw operator – takes seconds to make knockout holes, procedure is:
* Insert blade over interior angles of the longer cuts.
| * Make holes in several locations.
259
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #262)
Old Style Roof Const: Roof Cut; Knockout cuts are extremely valuable when:
Wind shifts cause the members on the roof to change their positions.
260
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #263)
Old Style Roof Const: Roof Cut; Members can begin opening hole when ___ outline is cut. Normally not a good idea to start pulling 1 cut section before remainder of the cut has been completed.
8’ x 8’
261
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #264)
Old Style Roof Const: If you only have 1 saw, the ___ (#) linear feet of cutting to make an 8x8 hole may take so complete that the interior forces may be driven out of the bldg:
55
262
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #265)
Old Style Roof Const: Roof Cut; Not good idea to start pulling 1 cut section before remainder of cut is completed, but may be necessary. 1 saw – may take too long & attack team is driven out. If 1st ¼ is pulled after making the initial ___ (#) cuts, attack team may be granted relief to remain in the area:
7
263
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #266)
Fig. 9-25: Removing a cut section of roof covering requires:
26: M’s pulling cut sections need to get a bite on the roof boards. ___ is the answer:
* Teamwork.
| * Providing plenty of knockouts
264
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #267)
Old Style Roof Const: Roof Cut; If a 2nd saw is available, usually best to complete all cuts before pulling 1st section of roof. Once again, the key factor is:
Direction of the wind
265
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #268)
(CFPC) If wind remains steady:
If wind is shifting:
* Steady - chances are won’t have problems cutting & pulling original hole – then original hole can be expanded to the full 8x8.
* Shifting – best to complete all cuts before you pull the hole, so you won’t be driven off by smoke & heat.
266
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #269)
Old Style Roof Const: Roof Cut; Occasionally may find that even with a good sized hole over the fire, conditions require further expansion to vent. Is it better to cut a new hole or extend existing cut?
Better to extend existing cut.
267
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #270)
Old Style Roof Const: Roof Cut; Reasons for why it is better to extend an existing cut rather than cutting a new hole:
* 1st reason - you’re certain you are in right location
| * 2nd reason - It takes less cutting since existing hole acts as 1 side of the extension.
268
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #271)
Old Style Roof Const: Roof Cut; Extending an existing cut – Cut to vent as many additional bays between ___ as possible, rather than ___:
* Joists as possible,
| * Rather than extending the channel between bays.
269
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #272)
Old Style Roof Const: Roof Cut; Joists act as ___, the more bays that are open, the faster things clear up. Keep wind at your back.
Draft curtains
270
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #273)
Old Style Roof Const: Roof Cut; At times, its not just smoke blowing out of the hole that drives you away, if might be heat from venting fire. Even if the wind is blowing fire away from you, ___ may make the approach impossible:
Radiant heat
271
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #274)
(CFPC) – You can beat this temporarily by using a ___ as shield, buying you time to complete a few more cuts or to start pulling the next section of the hole.
Cut section of roof
272
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #275)
Fig. 9-27: Use a cut section of roofing as a shield if fire prevents:
Close approach while extending the cut
273
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #276)
Old Style Roof Const: Many of the waterproofing materials used on roof decks are very:
Combustible
274
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #277)
Old Style Roof Const: Many of the waterproofing materials used on roof decks are very combustible. Older tar paper & newer rubber roofing, both burn with large quantities of (3):
* Black smoke,
* High heat.
* Lots of flame.
275
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #278)
Old Style Roof Const: Newer roofing materials often melt upon being heated & turn into a ___ when roof opening is pulled:
Flammable liquid pool
| having a hoseline in on the roof to control such fire from spreading across entire roof surface is recommended
276
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #279)
Old Style Roof Const: Operating a ___ into any ventilation opening is strictly forbidden:
Why?
• Hoseline
* Hole is there to let bad stuff out, a hose stream from the top simply blows it back towards the troops below.
* Won’t cool burning material under the roof – so it can’t put out the cockloft fire.
277
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #280)
Old Style Roof Const: Working closely over the seat of the fire demands continually evaluating:
The stability of the roof.
278
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #281)
Old Style Roof Const: Working closely over the seat of the fire demands continually evaluating the stability of the roof. If it is a standard roof, it is highly unlikely that the supports will weaken before the ___ have failed:
* Roof boards
* (On this style of roof – by time failure occurs, fire forces will have been driven back by fire venting out through the boards)
279
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #282)
The Inverted Roof: It is similar to the standard flat roof in that is constructed with a:
Cockloft – with 1 surface separated from the main roof joists by a light wooden framework.
280
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #283)
With an Inverted Roof, instead of ceiling being suspended below the joists by the framework, the roof boards are:
Raised above the joists on a framework of 2x4s
281
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #284)
The Inverted Roof – this style of roof was very common on many large-area flat roof built from the ___ to the ___ (years):
1920’s – 1960’s
282
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #285)
The Inverted Roof: Flat roofs aren’t usually truly flat. Some pitch must be built to allow for:
Drainage
283
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #286)
The Inverted Roof: Flat roofs - not usually flat. Have pitch for draining. Particularly where the roof beams are supported on ___, it becomes complex to arrange 2x12 or 3x12 joists at precisely the right angle to crease the desired runoff across a 150x200 H shaped bldg:
Bearing walls of masonry
284
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #287)
Fig. 9-28: (Inverted roof picture) The main roof joists are the level of ___:
And the roof itself is raised ___ above on 2x4s:
* The ceiling.
| * 4 feet.
285
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #288)
The Inverted Roof: When these bldgs were built, a simple means was to set al of the large timbers at a flat, level height & create a pitch by means of:
Upright posts at different lengths
286
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #289)
The Inverted Roof: These support a roof frame made of 2x4 uprights that can be cut into varying lengths (this technique was popular b4 power tools were common). By starting at 1 edge of the roof & cutting each successive row of supports ___, you can easily provide the desired pitch to a roof:
½” shorter than the last
287
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #290)
The Inverted Roof: A plate is nailed at the top of each row of uprights, to which the ___ are in turn nailed:
Roof boards
288
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #291)
The Inverted Roof: Typically each row of uprights consists of posts how far apart, with rows spaced how far:
* Posts – 2’ on center
| * Rows – 4’ on center
289
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #292)
The Inverted Roof: The lightweight construction don’t feel solid compared to standard roof (with its roof boards nailed directly to 3x12 joists) Inverted roof feel is:
* Very springy (this in normal).
| * Not to be taken as sign of impending failure.
290
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #293)
The Inverted Roof is relatively stable under fire conditions, for while its supported on lightweight frame work (2x4s), the frame is designed so that each portion rests directly on:
A support leading to the main joist at ceiling level
291
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #294)
The Inverted Roof: Modern lightweight wood trusses use 2x4s held together with:
A gusset plates or pins
292
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #295)
Unlike modern lightweight wood trusses (2x4s held together by w/ pins or gusset plate), the inverted roof doesn’t depend on a fastener to hold it in place. ___ does the job of that:
Gravity does the job of that – pulling each piece down onto the piece directly below.
293
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #296)
The Inverted Roof: Gravity holds in place – even when the 2x4’s burn through, roof will only drop (how far):
A ft or 2 - to the level of the main joists.
294
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #297)
Fig. 9-30: The ___ of the inverted roof are the last things to burn through:
As long as the deck cannot be punched through with a tool, there is little danger of:
* Main roof supports
| * Collapse
295
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #298)
The Inverted Roof: The main joists, being (located where), aren’t subject to the highest temperatures for some time & will remain in place to support the framework above:
Bottom of the cockloft
| This is indirect contrast to newer lightweight trusses – continued on next card
296
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #299)
The Inverted Roof: Newer lightweight trusses lose their entire strength when:
Often resulting in:
* Once a portion of the truss burns through (1 truss fails → all trusses failed)
* Often results in - Total collapse
297
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #300)
Cutting an inverted roof – proceed in same way as cutting a standard roof. Use extra caution to avoid making too deep a cut – which severs:
Parts of the 2x4 framework
298
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #301)
The Inverted Roof: Which 2 elements will allow members on the roof to evaluate more realistically just how bad conditions are (pertaining to an inverted roof fire):
* Early recognition of presence of an inverted roof &
| * An understanding of how an inverted roof behaves under fire conditions.
299
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #302)
The preferred way to recognize an inverted roof is during:
If not possible, then:
Prefire inspections
If not possible – inspect the supports when you make your 1st hole in the roof. If see 2x4s – caution flag! (cont. on next card)
300
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #303)
Inverted Roof - If prefire inspections not possible – inspect the supports when you make your 1st hole on roof. If see 2x4s – caution. Examine further to see if roof is of truss or inverted construction. Truss roof if see:
* Gusset plates or connectors are visible, or if;
* 2x4s join the top plate at other than right angles.
* (truss roof – make appropriate cut)
301
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #304)
Inverted Roof - If cut holes on roof & ID 2x4’s – examine for truss or inverted construction. Inverted roof if:
2x4s nailed directly atop the lower supports
302
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #305)
The Rain Roof can be encountered at any type of roof – flat, curved or peaked, of ___ or ___ construction:
Standard or truss
303
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #306)
The Rain Roof is built over a roof that has become so ___, that it no longer keeps the rain out:
Porous – that it no longer keeps the rain out
304
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #307)
The Rain Roof – The cheap way out of a porous roof is to leave the existing roof in place is to and:
Build a whole new one on a raised framework above the original.
305
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #308)
Dangers of adding a rain roof: (3)
1. The added weight was never designed into the original roof supports – which may be approaching point of failure.
2. The 2 layers can delay or prevent venting.
3. Multiple layers create multiple void spaces where fire can hide – can lead to conflicting estimates of a fire’s intensity.
306
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #309)
Fig. 9-31: A rain roof is similar to and more dangerous than which roof:
Inverted roof
307
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #310)
Fig. 9-31 (cont): Inverted roof – similar to inverted roof, but has added danger of (2):
* Extra weight
| * 2nd concealed void.
308
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #311)
Fig. 9-31 (cont): To detect a rain roof, do what:
Poke down with a hook or pike pole after making an inspection hole.
If hit solid roofing – alert IC.
309
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #312)
Rain Roof – If fire has entered 2nd cockloft, between rain roof & original cockloft, it’s virtually impossible to reach from below. The only approach is from:
Above
310
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #313)
Rain Roof fire will be a tremendously smoky fire because of ___ are left in place when the rain roof is put on.
Large parts of the original’s roof tar paper covering are left in place
311
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #314)
Rain Roof fire will be smoky. The original roof covering can blaze away in a concealed space, creating an extremely ___ smoke:
Dense, black smoke
312
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #315)
Rain Roof fire - A quick way to get water into this space is to use:
A cellar nozzle or distributor
313
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #316)
Rain Roof fire – the key to success for the entire operation depends on the roof team recognizing the presence of the rain roof early enough to permit:
Quick deployment of a hose stream to the area.
314
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #317)
Rain Roof – If fire mostly confined to the rain roofs 2md cockloft, the fire can be contained with minimal damage to the area below. The rain roof is supported by:
A raised wooden framework of 2x4s – that rest directly on the deck of the roof below.
315
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #318)
Rain Roof – Safe to work under circumstances (indicated on previous card). Like the ___ roof, there is not likely to be any large-scale collapse.
Inverted roof
316
Ch. 9: Norman – Ventilation
Section: Venting Flat Roofs (NC #319)
On a Rain Roof it is safe to work directly over the fire as long as:
The original roof joists below the rain roof are not heavily involved.
317
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #320)
New type of roof construction is appearing that has similar potential to a metal deck roof for raining ___ on materials below while impending access for hose streams:
Flaming droplets (Insulspan panel roof)
318
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #321)
The Insulspan panel is made out of:
Styrofoam insulation
319
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #322)
The Styrofoam insulation panels are sandwiched between 2 layers of?
Sandwiched together between 2 layers of OSB (oriented strand board)
(this creates very effective insulating material)
320
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #323)
Insulspan panels typically come in ___ widths & are up to ___ in length:
8’ W & 24’ L
321
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #324)
The Styrofoam & OSB are bonded together in such a way that the pieces act as a ___ unit:
Monolithic unit
322
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #325)
The insulspan panels require very little support, spanning an area as large as ___ without joists, creating cathedral ceilings:
24’
323
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #326)
The spanning of 24’ w/ out joists creates what type of ceiling:
Cathedral
324
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #327)
This type of roof (insulspan panels) is being installed on ___ & ___ developments around the US:
* New garden level apartment &
| * Townhouse (developments)
325
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #328)
Fig. 9-33: Insulspan panels extend from the ___ to the ___. No joists are required as the panel is self supporting:
From the ridgepole to the outer walls
326
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #329)
Difficulties created for FF’s – 1st is: nature of product; Styrofoam insulation is highly combustible (produces lg amount of toxic smoke & intense flame). OSB is also combustible (adds to fire load). The product is supposed to be installed with a ___ separating the panel from the occupancy?
* Gypsum ceiling
* (There is potential for fire venting out a window to ignite the edges of the roofing & spreading into the interior of the panels)
327
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #330)
If fire – stability of the roof under such conditions is questionable. Recommended to cut insulspan panel roofs only from (if possible)
The basket of an elevating platform
328
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #331)
2nd problem with insulspan panels is their thickness (1st was nature of product – combustible). Units installed in Brooklyn, NY are as much as ___ thick.
8½”
329
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #332)
The typical 12” circular saw has a depth of ___:
4”
| typical ventilation techniques impossible on insulspan panels due to thickness
330
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #333)
Insulspan panels are readily cut with a chain saw that has at least a ___ depth of cut.
Many fire service chain saws have ___ that does not allow such a deep cut:
* 9”
| * Chain guards
331
Ch. 9: Norman – Ventilation
Section: Insulspan Panels (NC #334)
The good news in this style of development (insulspan panels) is that with cathedral ceilings on the top floors, there is no ___ extending down the row to further the spread of fire:
No common cockloft
332
Ch. 9: Norman – Ventilation
(NC #335)
The ___ cut is a specialized type of cut used to create a fire break along the surface of the roof:
The trench cut
333
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #336)
In NYC, multi-winged apartment buildings are called ___, due to their general shape as seen from above:
* H-type bldgs
| * (Depending on layout – may be H, E or O shaped)
334
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #337)
The primary factor found in all of the bldgs (multi-winged) is a ___ over all of the wings:
Common cockloft over all of the wings
335
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #338)
Multi-winged bldgs – The adjacent sections of large areas are joined by a fairly narrow connecting section called:
The throat
336
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #339)
Many serious multiple alarms occur when fire is encountered in cockloft space. Once there, fire has full access to rest of bldg, often burning off the entire ___:
Roof & top floor
337
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #340)
FFs who are faced with a large body of fire in 1 wing of (of a multi-winged bldg) often have little choice but to:
Retreat & try to stop the fire from spreading to other wings.
338
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #341)
Fig. 9-35: Trench cuts work extremely well on bldgs that broken up into several wings that are connected by relatively ___ areas:
Throat areas
339
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #342)
Fig. 9-35 (cont): A properly located, cut & pulled trench in conjunction with ___ & ___ can stop the fire from extending from 1 wing to another:
* Hoseline support &
| * A main ventilation hole.
340
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #343)
The most logical place to cut an extending fire off is in the throat area, where the narrowness of the opening allows a limited number of personnel to:
Fight a holding action w/ out being outflanked by fire. (Cont on next card).
341
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #344)
(CFPC) The ___ on the sides of the throat assures that the fire cannot get behind you:
The open courtyard
342
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #345)
Members cutting vent holes on the roof realized it was possible to cut 2 parallel cuts from wall to wall faster than it was to cut several smaller vent holes, if the cuts were made in the ___ parts of the bldg:
The narrowest part of the bldg
| Thus was born the trench cut
343
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #346)
The trench cut is sometimes referred to as:
Strip ventilation
344
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #347)
The term ‘Trench Cut’ is preferred over ‘strip ventilation’ by Norman for 2 reasons:
* Trench should be used only as a defensive tactic - to imply that it is part of an acceptable routine offensive ventilation will result in using trenches at wrong times & places
* 2nd reason is strictly semantic – the word trench implies to a deep opening that is crucial to its effectiveness
345
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #348)
For trench cuts to be most successful, the ceiling below the roof opening must be pushed down (how far):
* The entire length & width of the cut
* (Removing as much fuel in the fire’s path as possible)
* (This exposes the fire to attack by hoselines on the top floor & improves conditions under which hoselines crews are working)
346
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #349)
Fig. 9-36: A trench cut is a defensive measure to ensure:
That a fire cannot extend past it, into another section of the bldg.
347
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #350)
Fig. 9-36 (cont): To make a trench work, the ceiling below must be completely removed, and hoselines should be positioned on the safe side of the trench. Trenches should be at least ___ wide:
3’ wide
348
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #351)
As its become better known, a major problem, has began to develop with the trench cut, in that it is often:
Used improperly
349
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #352)
Trench cut is a defensive tactic and it won’t replace a properly located ventilation hole. If trench cut is made before the primary hole is completed, the result is that:
The fire is rapidly drawn across the cockloft (sometimes past) the trench and into the next wing before the trench can be completely pulled.
350
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #353)
Cutting the trench – Making the trench is actually a process that should be divided into several steps as follows:
1. Locating the trench.
2. Cutting the inspection holes.
3. Cutting the trench.
4. Pulling the trench.
351
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #354)
Cutting the trench – The operation of cutting a trench cannot begin until:
The main ventilation hole has been completed
352
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #355)
Cutting the trench – The operation of cutting a trench cannot begin until the main ventilation hole has been completed. An exception might exist in larger depts where:
4 or more saws are immediately available
353
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #356)
Cutting the trench - Exception to trench operation being halted until main vent hole is completed is if 4+ saws are readily available. Operation of saws is used in which manner?
* 2 saws begin cutting trench.
* While remaining are committed to other roof vent functions – vent over stairs, shafts, top floors, windows, cutting main 8x8 vent hole.
* (other sequences of cutting/venting risks pulling fire faster than can control)
354
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #357)
Cutting the trench – Several considerations go into choosing the right location for the trench. 1st → the location must be close enough to the fire to limit ___. At the same time, it must be far enough away that you will:
Unnecessary extension.
Have enough time to complete cutting & pulling, as well as pushing ceiling down before the fire passes it.
355
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #358)
Considerations of choosing right location for trench: Close enough to limit unnecessary extension & far enough to allow time to complete cutting, pulling & pushing ceiling down b4 fire passes. Assuming main fire is below main vent hole & not closer to trench, right distance is?
About 20 – 25’ from the main vent hole
356
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #359)
Cutting the trench - 2nd concern of choosing right location for trench cut (1st is distance) is to locate it by taking advantage of the bldg’s construction to reduce as much as possible the amount of ___ required.
Cutting
357
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #360)
Cutting the trench - 2nd concern of choosing right location for trench cut (1st is distance) is to locate it by taking advantage of the bldg’s construction to reduce as much as possible of cutting required. This is done by?
* Making cut at narrowest point
| * (Take advantage of skylights or stair bulkheads that penetrate roof & act as fire barriers)
358
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #375)
Cutting the trench - Cuts must be parallel, as close to outer walls as possible, & then towards the center so that the trench is divided into a series of ___ (length) sections, with knockouts at each section.
3 or 4 feet long
359
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #361)
Fig. 9-38: When making trench cuts, the side which is being preserved is the safe side, which is also known as?
The foreground
360
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #362)
Cutting the trench – In some cases fire partitions (not true fire walls, but gypsum barriers that cannot be defended) don’t extend all the way through the roof, but stop at:
* The underside of the roof boards
* (Personnel pulling ceilings on the top floor may find these, usually at the wall between 2 apts).
* (These are good place to make a stand as bulk of fire will be slowed by the barrier)
361
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #363)
Cutting the trench: The less ___ & ___ required, the faster a cut can be made, and the greater the likelihood that trench will successfully stop extension.
Cutting & pulling
362
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #364)
Cutting the trench – The final consideration of choosing the right location for the trench is the likely direction of ___: (review all 3):
* Fire spread (3rd consideration)
* Close enough to fire to limit unnecessary extension & far enough to allow for completion of cutting & pulling as well as pushing ceiling down – 25’ (1st)
* Take advantage of bldgs construction to limit amount of cutting required (2nd)
363
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #365)
Cutting the trench - Final consideration is the likely direction of fire spread. If faced with situation where fire may spread in more than 1 direction & only have enough ff’s to cut 1 hole – estimate what?
* The most likely path & the area of greatest value.
* (Then use trench and hoselines at that point)
* (Other direction will have to do with hoselines alone until reinforcements arrive)
364
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #366)
Cutting the trench - The most likely direction of fire travel is usually the ___ side:
Downwind side
365
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #367)
Cutting the trench - The most likely direction of fire travel is usually downwind side. If there’s little/no wind, what factor comes into play:
* The pitch of the roof
| * (Fire spreads fastest from low to high points – position trench to block its access to the high points of roof)
366
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #368)
Cutting the trench – After choosing right location for cut, next step is to:
Make examination holes
367
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #369)
Cutting the trench - After determine proper location for cut, next step is to make examination holes: Positioning of exam holes is:
* On fire the side,
| * 5 or 6’ in front of the intended edge of cut.
368
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #370)
Cutting the trench – Purpose of examination holes is twofold. Reasons are:
1. Ensure that:
2. Serve as indicators as to when to:
1. Ensure that fire hasn’t yet passed the trench area (so time is not wasted).
2. Begin pulling the trench.
369
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #371)
Cutting the trench – In addition, more examination holes should be made on the safe side of the trench, just to be sure that:
No fire will get past.
370
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #372)
Cutting the trench - If no fire is found at the inspection holes, you can begin cutting the trench. Make 2 parallel cuts how far apart from outer wall to outer wall of bldg?
3’ apart from outer wall to outer wall of the bldg
371
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #373)
Cutting the trench – Trench should be narrower than 3’ because:
Making the trench much wider isn’t recommended since:
* Fire may jump past it.
* You may have to step over it to get back to the fire side once fire is brought under control. And wider cuts take longer to complete & pull – more cutting required & more nails to pull.
372
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #374)
Cutting the trench - With 2 parallel cuts made, next operation involves slicing the length of the trench into shorter sections & creating knockouts on the ___ side, where tools can grab roofing:
Fire side
373
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #376)
Cutting the trench – All personnel on fire side of the trench must have at least 2 ways off of the roof, not counting:
Crossing the trench
374
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #377)
Cutting the trench - Once trench is in 3 - 4’ sections, have 2 means of egress, not counting crossing trench. One or more hoselines should be positioned where:
On the top floor, on the safe side of the trench.
| Continued on next card
375
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #378)
Cutting the trench - One or more hoselines should be positioned on the top floor, on the safe side of the trench – and the ceilings in this area should be pulled or pushed down from the roof. Which is more effective and why:
* Pushing down is more effective.
* Bc members on the roof are in exactly the right location, while members on top floor don’t know exactly where the trench is located, how it runs, etc.
376
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #379)
Cutting the trench – Additional hoselines should also be positioned on the roof, also on the safe side of trench:
* Allow 1 - 1¾” per ___ below trench:
* And 1 – 1¾” for every ___ of trench on the roof:
* 1 – 1¾” per room below the trench.
* 1 – 1¾” for every 15 – 20’ of trench on the roof.
377
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #380)
Cutting the trench – Remember, this is a defensive strategy. Hoselines (on roof) should be committed early & be separate from the ___ lines:
Attack
378
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #381)
Cutting the trench – Once the trench has been cut, roof team must avoid the temptation to ___, lest they unnecessarily draw fire toward the fresh air:
Pull it open immediately
379
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #382)
Cutting the trench – Once trench has been cut, (roof team) must have patience to wait until ___. At this point, the entire trench should be pulled:
Wait until fire shows at exam holes on side of trench.
(Take care to remove all material below that the fire could travel along. If ceiling below hasn’t been completely pulled, roof Ms assist by pushing down)
380
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #383)
Cutting the trench – Keep any eye on the inspection holes made on safe side to ensure you aren’t being:
Outflanked
(by this point, all interior forces on the fire side of the trench should have been withdrawn, that area has been surrendered)
381
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #384)
Cutting the trench – After trench is pulled, interior crews on fire side of trench should be withdrawn as that area has been surrendered. Objective now is to be certain:
That the remainder of the structure is saved
382
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #385)
Fig. 9-39: Trench cut – need to push ceilings down below the trench to allow ___ access:
Stream
383
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #386)
Fig. 9-39 (cont): Hose stream from roof only used if ___ have been removed:
Hose stream from below used to:
* Interior forces have been removed.
| * Prevent extension.
384
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #387)
Fig. 9-37: 1 handline for every ___ of trench should be positioned on roof on safe side of the trench. These are last-ditch insurance policy to make certain fire does not get past the trench:
15 – 20’
385
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #388)
Cutting the trench – The use of hoselines into roof ventilation openings should be strictly forbidden. A trench cut is not an offensive ventilation hole, but rather a defensive home built fire stop. As such, using hoselines through this type of opening is acceptable. This is 1 reason for calling it a trench, rather than:
Strip ventilation – since we don’t operate hoselines into ventilation strips.
386
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #389)
Trench cuts are particularly suited for use in the ___ type bldg:
H-type bldg – where narrow areas form choke points between larger sections.
387
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #390)
Long, relatively narrow, garden-type apartment complexes may be candidates for trench cuts. Lg area structures (supermarkets & taxpayers) having a sizeable body of fire in the cockloft don’t generally benefit from trench cuts since:
Length of cut needed to go from wall to wall is impractical
388
Ch. 9: Norman – Ventilation
Section: Trench Cuts (NC #391)
(CFPC) - Cutting the trench – A 75’ deep store would require -
* Size of cuts & cross cuts:
* Total linear feet of cutting:
* 2 – 75’ parallel cuts &
* 20 – 25’ 3’ft long crosscuts (to subdivide trench into manageable pieces)
* More than 225 linear ft of cutting.
* (such bldgs → better to make multiple large vent holes over the fire)
389
Ch. 9: Norman – Ventilation
Section: Additional Considerations When Venting (NC #392)
Never ventilate where you will create a ___ problem:
Exposure
390
Ch. 9: Norman – Ventilation
Section: Additional Considerations When Venting (NC #393)
Horizontal & vertical ventilation can both be problems is fire venting from the opening exposes nearby:
People or bldgs
391
Ch. 9: Norman – Ventilation
Section: Additional Considerations When Venting (NC #394)
Example → If you will expose people on the fire escape above by breaking a fire escape window into a fire apartment, you must:
Withhold ventilation until those people have been removed or protected.
392
Ch. 9: Norman – Ventilation
Section: Additional Considerations When Venting (NC #395)
Fig. 9-41: When fire has gained a strong hold on a bldg & will likely vent through the roof, lines must be positioned to:
Protect taller, nearby structures
393
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #396)
Roof ops present unique hazards & difficulties. Some problems remedied by simple changes in actions or policies, while others require massive engineering & construction activities to resolve. In all cases, ___ the key is to initiating protective action since you must recognize that a problem exists before you can solve it.
Awareness
394
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #397)
Probably the greatest danger to FFs engaged in roof ventilation is the:
* Fellow FF - particularly M handling the power saw.
| * (can also be the M w/ the axe, hook, or any moving object in condition of poor visibility)
395
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #398)
In almost all cases (injuries are to someone other than saw operator). And in most cases, saw operators must hold the greatest responsibility for the injury if they fail to perform the most important job on the roof, which is:
To stop the saw from spinning whenever its raised from a cut
396
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #399)
Gunning the engine (on a power saw), engages an ___, which is present on all power saws and sets the blade or chain spinning:
Automatic clutch
(it takes several seconds for the blade to stop – during this time, it can cut through clothing, flesh, bones and just about anything else)
397
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #400)
(The way to stop such danger is) train all FFs never to allow a spinning blade or chain to get more than ___ off of the roof:
6”
(don’t begin to gun engine until you’re just about to penetrate roof – after hole is cut, lift saw just clear of the hole & then immediately set it back on the roof to stop the blade)
398
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #401)
If necessary to gun a bulky saw to keep it running, you must clear all personnel out of the area. Cut entire hole & shut down the saw as you make the last cut. A better move would be to:
Get another saw up to the roof
399
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #402)
The danger from live saws spinning is greatest when ___ is poor:
Visibility
400
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #403)
Danger from live saws spinning is greatest when visibility is poor. Under these conditions, however, the hazard to FFs isn’t just from the saw, but from ___ as well:
Their own movements
401
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #404)
FFs moving around in smoke & darkness must be absolutely certain of what is front of them before they commit any ___ to an area:
Weight
| they can only do this by probing in front of them with a tool
402
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #405)
Probing in front is easier said than done. (Saw operator may only have saw & no tool. In this case the saw operator should ___ before stepping as to avoid falling through:
Roll saw along the roof in front of him or her & gingerly test each footing before stepping
(CONC)
403
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #406)
(CFPC) - When visibility is completely obscured, saw operator should stop all movement, which may not be possible due to heat & fire being driven towards ff’s. In such case, M’s should -
Drop and crawl toward safety
404
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #407)
Another concern for all members (not just the roof team), involves ___ added to roofs as a security measure, a n increasingly common situation as crime rates go up:
Steel plating
405
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #408)
Steel plating added to roofs as a security measure is typically encountered in ___ occupancies, such as:
High value occupancies.
Such as jewelry & appliance stores, gun shops (and especially in high crime neighborhoods)
406
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #409)
Steel plating added as a security measure is:
* Size of sheets of steel:
* Thickness:
* Laid on how:
* 4x8 ft sheets of steel
* From 1/8” to ¼” thick
* Laid on entire roof surface & welded together.
407
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #410)
Steel plating on roof – makes ventilation impossible using conventional methods. Installation of a ___ system should be mandatory, but this takes time to complete:
Sprinkler
408
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #411)
Steel plating added to roofs → sprinkler system should be mandatory, but takes time to complete. In the mean time, warning signs should be posted, visible to FFs both on where:
Roof & those entering at the street level
409
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #412)
Steel plating added to roofs → Since roof ventilation won’t be possible, FFs will have to alter their usual tactics. In the event of a serious fire, ___ is likely:
Early collapse due to extra weight
410
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #413)
Steel plating added to roofs → On a 20x50 roof, how much weight does steel plating add:
8000 lbs
411
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #414)
Steel plating added to roofs → The presence of extra weight on a roof should also be highlighted in a departments (2):
* Surveys &
| * CADS reports (computer aided dispatching system)
412
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #415)
1 dangerous wt (on roofs) that can’t be planned or regulated is the accumulation of:
Snow and water
413
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #416)
The Roof Team’s Observations: Since roof personnel are often operating without direct supervision of a chief officer, they must know the ___ of the possible operations they may be called upon to carry out:
Strategic importance
414
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #417)
The Roof Team’s Observations: Even if the roof will not be cut, the roof team performs another, equally important task, they must be the:
Eyes & ears of the IC
(it is incumbent on them to recognize & report any dangerous conditions immediately – failure to do so may result in injury or death to civilians &/or FFs)
415
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #418)
Fig. 9-43: Reports from the roof level are critical to the IC’s strategy. Information that can be provided from Roof Team members includes:
* Bldg width & depth,
* Location of parapet wall,
* Exposures,
* Roof conditions,
* Weights on the roof, etc.
416
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #419)
The Roof Team’s Observations: A parapet usually does not indicate a ___, but it is a possible defendable fire barrier:
Fire wall
417
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #420)
Fig. 9-44: Critical items for the IC that are not visible from the street include:
* Any life hazard,
* Size of the bldg,
* Location of parapet wall,
* Location of the fire,
* Presence of heavy weights on the roof,
* Condition of the roof,
* Fire threatening exposures – esp. taller bldgs, wooden bldgs or 1 w/ windows overlooking roof.
418
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #421)
The Roof Team’s Observations: Metal deck roofs are dangerous to operate on over a fire, especially with the concentrated load of the air conditioners. They will fail with as little as ___ of fire exposure:
5 minutes
419
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #422)
The roof team can make or break the fight. Even if you elect to not cut a particular roof, someone needs to be sent early to this location (roof) at structures larger than ___, and they must be prepared to act as the eyes & ears of the IC:
Private dwellings
(roof team/person needs to be able to quickly & concisely paint a mental picture of all the critical factors that they can see & the IC cant)
420
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #423)
Critical items for the roof team to report to the IC → 1 - 3:
1. Any visible life hazard
2. Size/shape of bldg – particularly the depth.
3. Construction - paying particular attn to trusses)
421
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #424)
Critical items for the roof team to report to the IC → 4 & 5:
4. Condition of roof (saggy, spongy, etc)
5. Fire showing through roof – report whether it is burning through the roof or if it coming through preexisting openings (skylights, ventilators, etc)
422
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #425)
Critical items for the roof team to report to the IC → 6 & 7:
6. Threatened exposures, especially, taller bldgs downwind & wood-frame bldgs.
7. Weights resting on roof (AC’s, etc)
423
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #426)
Critical items for the roof team to report to the IC → 8 & 9:
8. Location of Parapet walls.
| 9. Shafts w/in bldg that may allow rapid vertical extension or extension to exposures.
424
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #427)
Critical items for the roof team to report to the IC → 10:
10. Setbacks or extensions from the rear or side of a bldg that aren’t visible from the street.
425
Ch. 9: Norman – Ventilation
Section: Roof Venting Hazards (NC #428)
Critical items for the roof team to report to the IC → List all 10:
1. Visible life hazard.
2. Size & shape of bldg.
3. Construction of roof.
4. Condition of roof.
5. Fire showing through roof.
6. Threatened exposures.
7. Weight resting on roof
8. Location of parapet walls
9. Shifts within bldg
10. Setbacks or extensions.
