Truck Flashcards
(53 cards)
Ventilation definition:
“systematic” removal of heat, smoke, and fire gases from a structure, replacing it with cooler, clean, fresh air
Effective ventilation will accomplish four main objectives:
- save lives
- assist in firefighter access
- control the horizontal spread of fire
- reduce the possibility of flashover/backdraft
Two methods of horizontal ventilation:
- natural
- positive pressure
What is the key to effective roof ventilation?
knowledge of rafter type and rafter direction
When operating on a lightweight truss roof, or suspected lightweight truss roof, the ventilation team shall never:
conduct ventilation directly over the fire
Two types of ventilation holes:
- heat hole (offensive)
- strip (defensive)
What must occur with strip ventilation? (Trench)
A heat hole
Heat hole must be cut first to slow the horizontal spread of the fire
A head cut must be performed on roofs covered with?
plywood and diagonal sheathing
Kerf cut definition:
single cut made through the roof decking, the same width as the saw blade. Not as effective but can be used as an alternative to using a smoke indicator hole
Plug cut definition:
triangular piece of roof comp removed to expose the sheathing, used to determine sheathing type and roof composition thickness
Skim cut definition:
Used when?
light cut through covering and plywood sheathing, skim the top of the rafters, used on panelized roofs when you louver off a purlin
Smoke indicator hole definition:
triangle cut through sheathing and roof material, indicator smoke/fire conditions, should be placed along the path of access/egress every few yards
45 degree inspection cut definition:
used to determine rafter type/direction, will also tell you sheathing type, thickness of roof comp, and act as smoke indicator
Saw operator should cut a min of ___ dice cuts prior to the puller removing sheathing
3
Always leave a min of ___ un pulled section between the cutter and the puller? (when dicing)
1
Panelized roof cutting techniques and mode of operation:
- drop method (offensive)
- pull back method (offensive)
- offensive louver (offensive)
- louver off lam/main beam (defensive)
- louver off purlin (defensive)
Book 29-
size up consists of 3 operations:
- analyze situation
- decide on plan (strategy)
- put plan into operation (tactics)
Conducting a building size up, focus on:
- construction style
- roof style
- construction method
- age of building
Ability to accurately estimate the amount of time that a structure can be considered structurally strong is dependent on:
- type of construction
- how long the fire has been building
- fire intensity
Gable roof, strength/hazards:
strengths: ridge and exterior walls
haz: trusses w/ metal gusset plates = short burn time and potential failure/collapse
T/F
Plywood will burn/fail at a faster rate than sheathing
True, plywood offers minimal resistance to fire
Hip roof, strengths/hazards:
strengths: ridge, valley, hip, and exterior walls are areas of strength
haz: if covered w/ tile, will need to be removed prior to cutting
Bridge truss, strengths/hazards:
strengths: well constructed, easily identifiable by its sloping ends
haz: strength is dependent on size of lumber and span of trusses. underside is usually common to interior of commercial warehouse
Bridge truss roofs usually found on:
commercial buildings constructed between 30s-40s. usually heavy grade construction
