CH 2 Flashcards
(36 cards)
Building Classifications
(5)
pg 44
Type I - fire resistive
Type II - noncombustible/ protected noncombustible
Type III - Exterior protected (masonry)
Type IV - Heavy timber
Type V - Wood frame
NFPA 220
pg 44
Standards on Types of Building Construction
details requirements for each of the classifications and sub classifications with a 3 digit code
Meaning of digits in NFPA 220
pg 44
First- fire resistance rating in hours of exterior bearing walls
Second- Fire resistance rating of structural frames or columns and girders that support loads of more than one floor
Third- Fire resistance rating of floor construction
Type I construction definition
pg 46
presence of non combustible structural components that have fire resistance ratings within a specified range
commonly constructed using protected steel frame or reinforced concrete
Variation in fire resistance by application (type I)
(5)
pg 44
-bearing walls, columns beams: 2-4 hours as specified by local code and construction classification
-floor construction: 2-3 hours
-roof deck and construction supporting the roof: 1-2 hours
-interior partitions enclosing stairwells and corridors: as specified by local code, usually 1-2 hours
-partitions separating occupancies or tenants: as specified by local code
Type 1 construction use of combustible materials
(9)
pg 47
fire retardant wood can be used in roofs and interior partitions according to code
*roof coverings
*interior floor finishes
*interior wall finishes and trims
*doors and door frames
*window sashes and frames
*platforms
*nailing and furring strips
*light transmitting plastics
*foam plastics subject to restrictions
Type II constructions specifications
pg 47
steel and concrete block as well as glass and aluminum can be used with limited structural role
omission of fire resistive rating in type II roof construction if:
pg 47
roof is located more than 20 feet above the floor
Type II-A construction:
pg 47
Type II-A (protected) requires that structural components have one-hour fire resistance
Type II-B construction:
pg 48
Type II-B allows structural components to remain unprotected
unprotected non combustable most common is steel
Speed at which unprotected members will fail depends on:
(3)
pg 48
ceiling heights of the building
size of the unprotected steel members
intensity and duration of the exposing fire
Type III commonly referred to as:
pg 48
ordinary construction
Structural specifications for type III construction
pg 48
exterior walls of masonry most frequently but any noncombustible material with required fire resistance can be used for exterior walls
Type III interior structural components that are permitted to be partially or wholly combustible:
(5)
pg 48
walls
columns
beams
floors
roofs
Subclassifications of type III characteristics
pg 48
IBC type IIIA and NFPA type III 2-1-1: structural components are required to have a fire rating. Can be protected by plaster or gypsum
IBC type IIIB and NFPA type III 2-0-0: unprotected steel is sometimes used to support combustible members
Typical floor joist material in type III
pg 48
nominal 2X10 inch
fundamental fire concerns with type III
pg 49
combustible concealed spaces
between floor and ceiling joists and studs in partition walls that are covered by interior finishes
must have fire stops
type III can include this kind of ceiling
pg 49
drop ceilings
type IV construction commonly known as
pg 49
heavy timber
exterior is masonry
interior structural components are combustible
two differences between type III and type IV
pg 49
in type IV beams, columns, floors and roofs are made of solid or laminated wood with dimensions greater than type III
concealed spaces are not permitted between structural components of type IV
type IV is the only type that does not have:
pg 49
A and B subdivisions
2HH is used instead
Minimum nominal dimensions for floor construction in type IV
pg 50
6x10 inch
type V construction
pg 50
all major structural components are permitted to be combustible
many are required to have 1 hour fire rating for structural components
fundamental problem with type V
pg 50
presence of extensive concealed voids and inherent combustibility it can become totally involved and completely destroyed by fire
