Section 1607

Live loads are those loads defined in Chapter 2 of this code.

For occupancies or uses not designated in Section 1607, the live load shall be determined in accordance with a method approved by the building official.

The live loads used in the design of buildings and other structures shall be the maximum loads expected by the intended use or occupancy but shall not be less than the minimum uniformly distributed live loads given in Table 1607.1.

Floors, roofs and other similar surfaces shall be designed to support the uniformly distributed live loads prescribed in Section 1607.3 or the concentrated live loads, given in Table 1607.1, whichever produces the greater load effects. Unless otherwise specified, the indicated concentration shall be assumed to be uniformly distributed over an area of 2 ¹ /2 feet by 2 ¹ /2 feet (762 mm by 762 mm) and shall be located so as to produce the maximum load effects in the structural members.

In office buildings and in other buildings where partition locations are subject to change, provisions for partition weight shall be made, whether or not partitions are shown on the construction documents, unless the specified live load is 80 psf (3.83 kN/m ² ) or greater. The partition load shall be not less than a uniformly distributed live load of 15 psf (0.72 kN/m ² ).

following combinations. Where using these alternative allowable stress load combinations that include wind or seismic loads, allowable stresses are permitted to be increased or load combinations reduced where permitted by the material chapter of this code or the referenced standards. For load combinations that include the counteracting effects of dead and wind loads, only two-thirds of the minimum dead load likely to be in place during a design wind event shall be used. Where using these alternative load combinations to evaluate sliding, overturning and soil bearing at the soil-structure interface, the reduction of foundation overturning from Section 12.13.4 in ASCE 7 shall not be used. Where using these alternative basic load combinations for proportioning foundations for loadings, which include seismic loads, the vertical seismic load effect, Ev, in Equation 12.4-4 of ASCE 7 is permitted to be taken equal to zero. Where required by ASCE 7, Chapters 12, 13 and 15, the load combinations including overstrength of ASCE 7, Section 2.3.6 shall be used. [OSHPD 1R, 2B & 5] Each load combination shall be investigated with one or more of the variable loads set to zero.

D + L + ( Lr or S or R ) (Equation 16- 1 )

D + L + 0.6 W (Equation 16- 2 )

D + L + 0.6 W + S /2 (Equation 16- 3 )

D + L + S + 0.6 W /2 (Equation 16- 4 )

D + L + S + E /1.4 (Equation 16- 5 )

0.9 D + E /1.4 (Equation 16- 6 )

Exceptions:

1. Crane hook loads need not be combined with roof live loads or with more than three-fourths of the snow load or one-half of the wind load.

2. Flat roof snow loads of 30 pounds per square foot (1.44 kN/m ² ) or less and roof live loads of 30 pounds per square foot (1.44 kN/m ² ) or less need not be combined with seismic loads. Where flat roof snow loads exceed 30 pounds per square foot (1.44 kN/m ² ), 20 percent shall be combined with seismic loads.