BC 2 Flashcards
NFPA 220
standard for types of building construction
3 digit code for each construction type
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 1- fire resistive
presence of noncombustible components that have fire resistance ratings within a specified range
ex-
bearing walls, columns and beans:2-4 hours
floors: 2-3 hours
roof deck and construction supporting roof: 1-2
interior partitions enclosing stair wells and corridors: 1-2 hours
partitions separating occupants and tenants: as specified by local code
unprotected steel
no fire resistance
combustible materials allowed in type 1 for
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 2 constructions
wider range of materials than type 1
glass and aluminum can have a limited structural role
roof can be non fire resistive more than 20 feet above the floor
type 2A construction (protected)
requires structural components to have a 1 hour fire resistance
type 2B (unprotected)
allows structural components to remain unprotected.
usually steel beams
type 3 ordinary construction
usually exterior masonry walls
interior structural components can be partially or wholly combustible including: walls, columns, beams, floors, roofs
includes drop ceilings
type 3A and NFPA type 3 2-1-1
structural components can be protected by plaster or gypsum board
type 3b NFPA 3 2-0-0
unprotected steel is sometimes used to support combustible members
type 3 construction has combustable concealed spaces created between floor ad ceiling joists and between studs in partition walls when covered with interior finish materials
must have fire stops
type 4 heavy timber or mill
exterior is normally masonry and inside is combustable
beams columns floors and roofs are made of said or laminated wood with greater dimensions than type 3
concealed spaces are not permitted between structural components
doesn’t use a and b subdivisions
uses 2HH
requires 6x10 inch floor construction
type 5 wood frame
all major structural components can be combustible
1 hour fire resistance
extensive concealed spaces
light frame construction
introduced in 1830s