Chp. 2 Bldg Classifications & Structural Fire Resistance Flashcards
What are the five basic building classifications used to classify structures by the materials used in their construction ?
- Type I : Fire Resistive
- Type II : Noncombustible or Protected Noncombustible
- Type III : Exterior Protected (masonry)
- Type IV : Heavy Timber
- Type V : Wood Frame
Building classifications can help firefighters determine the likelihood of ______________ under fire conditions. They also indicate the degree of ______________ provided by the buildings construction.
- structural collapse
- occupant safety
The building classifications used in the building codes are based on the ______________ and the ________________ required for the structural components.
- materials used in construction
- fire resistance ratings
With the exception of ____________ the major classifications are further divided into two or three subclassifications. The highest requirements for fire resistance are for ____________ construction, with lower requirements for the other types of construction.
- Type IV, heavy timber
- Type I
In NFPA 220, each classification is designated by a three-digit number code. What does each digit represent?
- 1st digit : fire resistance rating (in hours) of exterior bearing walls.
- 2nd digit : fire resistance rating of structural frames or columns and girders that support loads of more than one floor.
- 3rd digit : fire resistance rating of the floor construction.
Type I construction is classified by the presence of ____________________ that have fire resistance ratings within a specified range.
noncombustible structural components
The addition of ____________ increases structural integrity during a fire.
fire resistance
Bearing walls, columns, and beams provide how many hours of fire resistance?
Two to four hours, as specified by the local code and the construction classification.
Floor construction provides how many hours of fire resistance?
Two OR three hours
Roof deck and construction supporting the roof provide how many hours of fire resistance?
One to two hours
Interior partitions enclosing stairwells and corridors provide how many hours of fire resistance?
As specified by the local code ; usually one OR two hours
Partitions separating occupancies or tenants provide how many hours of fire resistance?
As specified by the local code
Type I buildings are most commonly constructed using a _______________ or ________________.
- protected steel frame
- reinforced concrete
Concrete is an inherently ______________ material with good thermal insulating properties.
noncombustible
Building codes usually permit a limited use of combustible materials in Type I construction. A code may also allow the use of _________________ treated wood in roofs or interior partitions.
fire retardant
Some building codes contain a provision to omit the fire-resistive rating for a roof construction for some occupancy types when the roof is located more than how many feet above the floor?
20 feet
Type II A ______________, requires that structural components have __________ fire resistance.
- protected
- one hour
In unprotected noncombustible construction, the major structural components have _______________.
no fire resistance
The speed at which unprotected members will fail, depends on what factors?
- Ceiling height of the building
- Size of the unprotected steel members
- Intensity and duration of the exposing fire
In Type III construction, interior structural components that are permitted to be partially or wholly combustible are:
- walls
- columns
- beams
- floors
- roofs
Type III construction commonly uses what size joists for floor construction?
nominal 2 inch x 10 inch
A fundamental fire concern with Type III construction is the ________________ that are created between floor and ceiling joists and between studs in partition walls when they are covered with interior finish materials.
combustible concealed spaces
Two important distinctions between Type III and Type IV construction are :
- In Type IV construction the beams, columns, floors, and roofs are made of solid or laminated wood with dimensions greater than in Type III construction.
- Concealed spaces are not permitted between structural components in Type IV construction.
Type IV construction requires minimum nominal dimensions of ___________ for floor construction, which is thicker than needed in Types III and V construction.
6 inch x 10 inch
Many Type V structures are required to have a ____________ for structural components.
1 hour fire resistance
The fundamental problem with Type V construction is the presence of _______________.
entensive concealed voids
Classifying buildings according to ____________ facilitates the administration of a code.
occupancy
What are the ten major occupancy classifications of the International Building Code (IBC), and how many subgroups are within those classifications?
- Assembly Group A
- Business Group B
- Educational Group E
- Factories Group F
- High Hazard Group H
- Institutional Group I
- Mercantile Group M
- Residential Group R
- Storage Group S
- Utility and Miscellaneous Group U
- a total of 26 subgroups
NFPA 5000 Building Construction and Safety Code, and NFPA 101 Life Safety Code identify what 12 major classifications?
- Assembly
- Educational
- Day Care
- Health Care
- Ambulatory Health Care
- Detention and Correctional
- Residential
- Residential Board and Care
- Mercantile
- Business
- Industrial
- Storage
Required occupancy separations can range anywhere from _____________ dependent on the local building code.
one to four hours
The total quantity of combustible material in a compartment that is a critical factor when determining the fire safety requirements of a space.
Fuel load
The maximum amount of heat that can be released if all fuel is consumed.
Fire load
The fire load will vary depending on the _____________ of the fuel load.
heat of combustion
IBC defines a noncombustible material as being …
“in the form in which used and under the conditions anticipated, will not ignite, burn, support combustion or release flammable vapors, when subjected to fire or heat.”
Fire resistance describes several properties of a material , including…
- Combustibility
- Thermal conductivity
- Chemical composition
- Density
- Dimensions
The fire resistance ratings incorporated into the building codes include minimum requirements for structural components such as :
- Beams
- Columns
- Walls and partitions
- Floor and ceiling assemblies
- Roof and ceiling assemblies
The most commonly used test for determining combustibility is…
ASTME 136, Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750 degrees C.
The only standardized test method currently universally accepted by building codes that evaluates the ability of structural assemblies to carry a structural load and to act as afire barrier.
E-119
What methods are used to determine and calculate fire resistance of building materials?
- Laboratory testing
- Mathematical models
- Statistical data
The structural fire resistance of building components is determined most often thorough ______________.
laboratory testing
