Book 29: Ventilation Techniques Flashcards
What is ventilation?
Ventilation is the “systematic” removal of heat, smoke, and fire gases from a structure, and replacing it with cooler, clean, fresh air.
Effective ventilation will accomplish what 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
_____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
According to book 29, how many firefighter deaths are attributed to flashover?
100 deaths on average 85 due to flashover
In a confined area, if the structure’s contents reach their ignition temperature and there is not sufficient oxygen to support combustion; all that is needed is an air (oxygen) supply to explosively change the superheated area into an instant inferno. This condition is best known as ______
Backdraft
What are the two types of ventilation
Horizontal and vertical ventilation
____ _____is the systematic removal of heat, smoke, and fire gases through wall openings such as doors and windows.
Horizontal ventilation
What two methods are performed with horizontal ventilation?
Natural and positive pressure ventilation.
_____ _____is easily done by opening doors and windows and allowing the wind to ventilate the building.
Natural ventilation
_____ ______ ______is a method of forcing clean, fresh, pressurized air into a structure with blowers. By systematically opening doors and windows to channel the pressurized clean air, you can effectively ventilate smoke out of a structure.
Positive pressure ventilation
______ ______is the opening of the roof or existing roof openings (skylights, hatch covers, etc.) for the purpose of allowing heat, smoke, and fire gases to escape from the structure into the atmosphere.
Verticals ventilation
What are the 2 types of ventilation holes?
Heat Hole (Offensive) Strip Ventilation (Defensive).
A ____ _____ is a hole placed directly over the fire or as close to the fire as safety will allow.
Heat hole
When cutting on a lightweight roof should employ what practice?
“trading space for time”
____ _____helps to stop the horizontal spread of fire. must be done in conjunction with a heat hole.
Strip ventilation
_____ _____ ___is a technique used when cutting plywood sheathing (4 cuts). Center rafter provides the largest hole possible with the ______amount of cuts.
Center rafter cut
Minimum
_____is the material used to comprise the base and exterior covering for the roof. The base material can consist of solid wood sheathing, plywood-type materials, corrugated metal, and other materials
Decking
Plywood sheathing is installed so that the __’ dimension of the plywood crosses the rafters or joists and the __’ dimension parallels the rafters or joists. The sheets of plywood are then staggered much like a brick or block wall. This is called
8’
4’
Diaphragm nailing
____ ____ are made parallel to ____with no concern to locating rafters.
Dice cuts
Rafters
___ _____ are metal clips used to hold the butted ends of plywood together. They are common on _____roofs.
“H” clips
Pitched
____ __ ____is a cut made through the roof decking that is made perpendicular to rafters. This cut is used to locate _____This cut involves ______ rafters. must be done on roofs covered with ______ and _______ _______. This cut is usually the first cut made on a _____ _____ ____.
A head cut
Rafter
Rolling
Plywood and diagonal sheathing
Center rafter cut
____ _____ _____motion brings the pulling tool under and up to the decking in a smooth, forceful motion that will separate the decking materials from the rafters.
The “J” hook
____ _____ ____ is a single cut made through the roof decking, the same width as the ____ ____ ____. Although not as effective, the kerf cut can be used as an alternative to using the _____ _____ _____.
A kerf cut
Chain saw lade
Smoke indicator hole
Where should ground ladders be thrown?
Uninvolved corners of the structure.
A minimum of _ ladders should be thrown to an involved structure
2
Once all 4 cuts are complete, use a rubbish hook and push down on the ____ side (the side closest to your _____and pull on the far side. This method is used with the center rafter louver technique. This is?
Near side
Ladder
Louver
_____ _____ are usually made from a 2” x 4” laid flat between rafters to provide a nailing surface for the edge of the plywood sheathing. Since the plywood normally used is _’ x _’ in size, a nailing block will usually be found every __feet.
Nailing blocks
4’x8’
4 feet
A cut through the roof decking made parallel to the roof rafters.
Parallel cut
A door leading from the interior stairwell to the roof.
Penthouse door
____ ____is a small triangular piece of roof covering (composition), which is removed from the roof to expose the roof sheathing.
A plug cut
Rolling rafters is used to make___?
A head cut
_____ _____ ___is a light cut of the roof covering, usually composition only. This cut is used to facilitate the removal of multiple layers of ______ ______(______).
A score cut
Roofing material (composition)
___ ____ ____is a light cut made with the chain saw, cutting through the roof covering and plywood sheathing. The saw is not inserted deep enough to cut through the ______. You “___” over the top of the rafters.
A skim cut
Rafters
Skim
_____ ____ when used in conjunction with an offensive ventilation hole (heat hole), can help stop the horizontal spread of fire.
Strip ventilation
With conventional construction, if time and safety permits, the roof team “___” cut the heat hole directly ____ ___ ____
Will
Over the fire
When operating on a ____ ____ ___roof (or suspected lightweight truss), the ventilation team shall never conduct ventilation operations directly over the fire.
Lightweight truss roof
On a lightweight truss roof, 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.
Trading space for time
On roofs sheathed with plywood, the “Head Cut” is made _______ to rafters. You need to know ____ ______ in order to accomplish any Heat Hole or Strip Ventilation Hole.
Perpendicular
Rafter direction
A properly placed heat hole saves lives and will allow firefighter access by reducing____, _____, and ____ ____inside the structure.
Heat smoke and fire gases