BOOK 29 Truck Operations Manual- VENTILATION Flashcards
Ventilation is the ______ removal of ______ , ______ , and ______ from a structure, and replacing it with cooler, clean, fresh air.
“Systematic”
Heat, smoke, and fire gasses
Effective ventilation will accomplish four main objectives.
- Save lives.
- Assist in firefighter access.
- Control the horizontal spread of fire.
- Reduce the possibility of flashover and backdraft.
If the heat, smoke, and fire gases are not released, they will accumulate at the highest point of the structure and begin to bank down and spread laterally. This process is generally known as?
Mushrooming
Strip ventilation, when used in conjunction with an offensive ventilation hole (heat hole), can help stop the horizontal spread of fire.
REDUCES THE POSSIBILITY OF?
FLASHOVER AND BACKDRAFT
__________ is a condition where all of the contents of a room are heated to their ignition temperature. Once their ignition temperature is reached, the entire room will quickly be involved in flames.
FLASHOVER
In a confined area, if the structure’s contents reach their ignition temperature and there is not sufficient oxygen to support combustion, a very dangerous condition exists. Once oxygen is re introduced THIS may occur
BACKDRAFT
____________ is the systematic removal of heat, smoke, and fire gases through wall openings such as doors and windows.
HORIZONTAL VENTILATION
With are the two methods to perform horizontal ventilation?
Natural and positive pressure
What are the 2 types of ventilation holes?
- Heat hole (offensive)
2. Strip ventilation (defensive)
On a conventional roof, where WILL a heat hole be placed?
Directly over the fire or as close to the fire as safety will allow.
When operating on any lightweight roof, or suspected lightweight roof (panelized or lightweight truss), the ventilation team shall ______ conduct ventilation operations directly over the fire. Members should employ the practice of “_______________” so that they may complete their roof-cutting operation prior to the fire impinging on a given ventilation hole.
NEVER
“Trading space for time”
A ___________ hole should be placed well ahead of the fire, and should extend the entire width of the building, creating a firebreak.
Strip ventilation
Technique used to cut 1” x 4” or 1” x 6” solid, spaced, or diagonally sheathed roofs. These cuts are made parallel to rafters with no concern to locating rafters.
DICING
Metal clips used to hold the butted ends of plywood together and are common on pitched roofs.
“H” clips
Material used to comprise the base and exterior covering for the roof. The base is the material attached to the roof rafters. The base material can consist of solid wood sheathing, plywood-type materials, corrugated metal, and other materials.
DECKING
A _________ is a cut made through the roof decking that is made perpendicular to rafters and also used to locate rafters.
Head cut
The removal of sheathing is enhanced by a __________ motion with an appropriate tool (pick head axe).
“J” hook
A _______ cut is a single cut made through the roof decking, the same width as the chain saw blade.
KERF
For roof ventilation, a “MINIMUM” of _____ ladders should be thrown to the involved structure.
TWO
Nailing blocks are usually made from a ______ laid flat between ________ to provide a nailing surface for the edge of the plywood sheathing.
2x4
RAFTERS
Nailing blocks are typically found every __ feet.
4
A small triangular piece of roof covering (composition), which is removed from the roof to expose the roof sheathing.
Plug cut
A PLUG CUT is used to identify what two features?
Sheathing type and roof comp thickness
A ______ cut is a light cut of the roof covering, usually composition only.
SCORE
A SCORE cut is used to facilitate the removal of what?
Multiple layers of roofing material (composition)
A ______ cut is a light cut made with the chain saw, cutting through the roof covering and plywood sheathing.
SKIM
The skim cut is used on a panelized roof when you are performing the cutting technique known as “_______________.”
“Louvre off a purlin”
A ________________ is a small triangular hole cut through the roof decking (sheathing and roofing material) made with the chain saw or an axe.
Smoke indicator hole
A smoke indicator hole is used to indicate what?
Smoke and fire conditions directly below the indicator hole.
Because of its weight and reach, a ____________is superior to, and recommended over, a pick-head axe as a sounding tool.
A long-handled rubbish hook
___________ is a long, narrow section of roofing material that has been removed well ahead of the fire and acts as a firebreak.
Strip ventilation
A turbine-style ventilator is about _____ more effective when the turbine is spinning.
30%
A _______ cut is a series of two cuts used to identify rafter direction “ONLY.”
45-degree
a 45-degree “inspection”cut will tell you what 4 things?
1) rafter type and rafter direction
2) the sheathing type
3) the thickness of roof composition
4) it can act as a smoke indicator hole.
When making a 45-degree inspection cut, the saw makes contact with the rafter, roll the rafter, and continue to cut for approximately _______ inches.
6-10
How many dices should the chainsaw operator cut before the puller starts removing the sheathing?
3
On a panelized roof, cut __ - __ inches inside of the purlins to avoid hitting metal hangers.
4-6
To louver off of a lam-beam, reach out approximately ___ feet, and make first cut parallel to rafters from purlin to purlin.
3 1/2’
When performing louver off a purlin, perform a “________” over the rafters lam beam to lam beam.
“Skim cut”
