International Building Code 1602.1
Definitions. The following words and terms shall, for
the purposes of this chapter, have the meanings shown herein.
ALLOWABLE STRESS DESIGN. A method of proportioning
structural members, such that elastically computed stresses
produced in the members by nominal loads do not exceed specified
allowable stresses (also called “working stress design”).
BALCONY, EXTERIOR. An exterior floor projecting from
and supported by a structure without additional independent
DEAD LOADS. The weight of materials of construction
incorporated into the building, including but not limited to
walls, floors, roofs, ceilings, stairways, built-in partitions, finishes,
cladding and other similarly incorporated architectural
and structural items, and the weight of fixed service equipment,
such as cranes, plumbing stacks and risers, electrical feeders,
heating, ventilating and air-conditioning systems and fire
DECK. An exterior floor supported on at least two opposing
sides by an adjacent structure, and/or posts, piers or other independent
DESIGN STRENGTH. The product of the nominal strength
and a resistance factor (or strength reduction factor).
DIAPHRAGM. A horizontal or sloped system acting to transmit
lateral forces to the vertical-resisting elements. When the
term “diaphragm” is used, it shall include horizontal bracing
Diaphragm, blocked. In light-frame construction, a diaphragm
in which all sheathing edges not occurring on a
framing member are supported on and fastened to blocking.
Diaphragm boundary. In light-frame construction, a location
where shear is transferred into or out of the diaphragm
sheathing. Transfer is either to a boundary element or to
another force-resisting element.
Diaphragm chord. A diaphragm boundary element perpendicular
to the applied load that is assumed to take axial
stresses due to the diaphragm moment.
Diaphragm flexible. A diaphragm is flexible for the purpose
of distribution of story shear and torsional moment
where so indicated in Section 12.3.1 ofASCE7, as modified
in Section 1613.6.1.
Diaphragm, rigid. A diaphragm is rigid for the purpose of
distribution of story shear and torsional moment when the
lateral deformation of the diaphragm is less than or equal to
two times the average story drift.
DURATION OF LOAD. The period of continuous application
of a given load, or the aggregate of periods of intermittent
applications of the same load.
ESSENTIAL FACILITIES. Buildings and other structures
that are intended to remain operational in the event of extreme
environmental loading from flood, wind, snowor earthquakes.
FABRIC PARTITIONS. A partition consisting of a finished
surface made of fabric, without a continuous rigid backing, that
is directly attached to a framing system in which the vertical
framing members are spaced greater than 4 feet (1219 mm) on
FACTOREDLOAD. The product of a nominal load and a load
GUARD. See Section 1002.1.
IMPACT LOAD. The load resulting from moving machinery,
elevators, craneways, vehicles and other similar forces and
kinetic loads, pressure and possible surcharge from fixed or
LIMIT STATE. A condition beyond which a structure or
member becomes unfit for service and is judged to be no longer
useful for its intended function (serviceability limit state) or to
be unsafe (strength limit state).
LIVE LOADS. Those loads produced by the use and occupancy
of the building or other structure and do not include construction
or environmental loads such as wind load, snow load,
rain load, earthquake load, flood load or dead load.
LIVE LOADS (ROOF). Those loads produced (1) during
maintenance by workers, equipment and materials; and (2)
during the life of the structure by movable objects such as
planters and by people.
method of proportioning structural members and their connections
using load and resistance factors such that no applicable
limit state is reached when the structure is subjected to appropriate
load combinations. The term “LRFD” is used in the
design of steel and wood structures.
LOAD EFFECTS. Forces and deformations produced in
structural members by the applied loads.
LOAD FACTOR. A factor that accounts for deviations of the
actual load from the nominal load, for uncertainties in the analysis
that transforms the load into a load effect, and for the probability
that more than one extreme load will occur
LOADS. Forces or other actions that result from the weight of
building materials, occupants and their possessions, environ-
2006 INTERNATIONAL BUILDING CODE 277
mental effects, differential movement and restrained dimensional
changes. Permanent loads are those loads in which
variations over time are rare or of small magnitude, such as
dead loads. All other loads are variable loads (see also “Nominal
NOMINALLOADS. The magnitudes of the loads specified in
this chapter (dead, live, soil, wind, snow, rain, flood and earthquake).
OCCUPANCY CATEGORY. A category used to determine
structural requirements based on occupancy.
OTHER STRUCTURES. Structures, other than buildings,
for which loads are specified in this chapter.
PANEL (PARTOF A STRUCTURE). The section of a floor,
wall or roof comprised between the supporting frame of two
adjacent rows of columns and girders or column bands of floor
or roof construction.
RESISTANCE FACTOR. A factor that accounts for deviations
of the actual strength from the nominal strength and the
manner and consequences of failure (also called “strength
STRENGTH, NOMINAL. The capacity of a structure or
member to resist the effects of loads, as determined by computations
using specified material strengths and dimensions and
equations derived from accepted principles of structural
mechanics or by field tests or laboratory tests of scaled models,
allowing for modeling effects and differences between laboratory
and field conditions.
STRENGTH, REQUIRED. Strength of a member, cross section
or connection required to resist factored loads or related
internal moments and forces in such combinations as stipulated
by these provisions.
STRENGTH DESIGN. A method of proportioning structural
members such that the computed forces produced in the members
by factored loads do not exceed the member design
strength [also called “load and resistance factor design”
(LRFD)]. The term “strength design” is used in the design of
concrete and masonry structural elements.
VEHICLE BARRIER SYSTEM. A system of building components
near open sides of a garage floor or ramp or building
walls that act as restraints for vehicles.
D = Dead load.
E = Combined effect of horizontal and vertical earthquake
induced forces as defined in Section 12.4.2 of
Em = Maximum seismic load effect of horizontal and vertical
seismic forces as set forth in Section 12.4.3 of
F = Load due to fluids with well-defined pressures and
Fa = Flood load.
H = Load due to lateral earth pressures, ground water
pressure or pressure of bulk materials.
L = Live load, except roof live load, including any permitted
live load reduction.
Lr = Roof live load including any permitted live load
R = Rain load.
S = Snow load.
T = Self-straining force arising from contraction or
expansion resulting from temperature change,
shrinkage, moisture change, creep in component
materials, movement due to differential settlement
or combinations thereof.
W = Load due to wind pressure.