03 Building Construction: Firefighting Problems and Structural Hazards Flashcards
Five Standard Types of Building Construction
Fire-resistive
Noncombustible/Limited combustible
Ordinary (brick-and-wood-joist)
Heavy timber
Wood Frame
What is the major fire problem in a fire-resistive building?
The central air-conditioning system
In a low-rise building smoke spreads by four means. A high-rise adds another means of spreading.
Heat
Convection currents
Fire Pressure
Wind
High-Rise: HVAC System
3/4 of all fire deaths are caused by what?
Smoke, not fire.
Experience has shown that FFs operating hoselines cannot extinguish fires in floor areas over what?
5,000 sq. ft.
What is the major fire problem in noncombustible/limited combustible buildings?
The flat, combustible asphalt roof deck covering that can ignite during a fire.
What is the major fire problem in ordinary buildings?
Fire and smoke spread throughout concealed spaces.
The largest and most serious concealed space is the _______________________.
Common roof space or cockloft (the space above the ceiling but below the roof)
What is the major fire problem in heavy timber buildings?
The large wooden interior timber framework.
To qualify as a heavy timber construction, a wood column cannot be less than ________ thick in any dimension and a wood girder cannot be less than ________ thick.
8in / 6in
What is the major fire problem in wood-frame buildings?
The combustible exterior walls.
Why could a floor collapse before it’s fire-rated time?
- The actual fire may be more intense than the test fire
- A small-scale sample of a floor cannot predict the way a full-scale floor will be affected by fire
- The bearing wall, column, or girder supporting the floor may collapse, cause the floor to fail.
- The fire may burn undetected for longer than thought
- The workmanship and materials of the actual building floor may be inferior to the test floor
What are the two types of fire-resistive construction?
Reinforced Concrete
Structural Steel
Concrete ceiling collapse in a reinforced concrete fire resistive building is caused by spalling. What is spalling?
Spalling is the rapid expansion of heated moisture inside the concrete.
In a steel skeleton construction, the under side of each floor is not concrete; each floor consists of a light-guage steel sheet, called a __________________, which supports several inches of concrete flooring above it.
Fluted metal deck
What is becoming the nation’s most widely used construction type?
Noncombustible/limited combustible
The three basic types of noncombustible buildings:
- The “steel building” metal-frame structure
- The metal-frame structure, enclosed by concrete block, nonbearing exterior walls
- The concrete block bearing walls supporting a metal roof structure
The collapse danger of a noncombustible building is…
- Roof cave-in
- the collapsing material
- the unprotected steel open-web bar joist.
Main advantage and disadvantage of the open-web bar joist:
Advantage: does not add fuel to fire
Disadvantage: It’s susceptibility to damage by fire
What is the main structural hazard of noncombustible construction.
The open-web bar joist
The structural hazard of ordinary constructed buildings is…
The parapet wall
What is the structural hazards of heavy timber construction?
Falling masonry walls that crash to the ground and spray bouncing chunks of bricks and mortar
The structural hazard of a wood-frame building is what?
The combustible bearing walls constructed of 2x4 wood studs.
Which walls are usually the bearing walls in a wood-frame building?
The two side walls. Usually the front and rear are nonbearing walls.
