Live Load Reduction Roof

For uses other than storage where approved additional live load reductions shall be permitted where shown by the registered design professional that a rational approach has been used and that such reductions are warranted.

Live load reduction roof.

The user can specify which load types are to be considered in this determination for the purpose of calculating live load reduction. The live loads for members supporting two or more floors are permitted to be reduced by a maximum of 20 percent but the live load shall not be less than l as calculated in section 1607 10 1. Where l r shall not be less than 12 psf and not more than 20 psf. Roof live load may be reduced by the following equation.

If the roof design load is 20psf and you are considering the compression in a web member that is located near the mid span than i would not use live load reduction for the compression in that member. One for the tributary area supported by the structural element r 1 and the other for the slope of the roof surface r 2. The live load on a roof is the weight of any temporary objects on the roof. Where uniform roof live loads are reduced to less than 20 psf 0 96 kn m 2 in accordance with section 1607 13 2 1 and are applied to the design of structural members arranged so as to create continuity the reduced roof live load shall be applied to adjacent spans or to alternate spans whichever produces the most unfavorable load effect.

Roof live load reduction. In some building codes the live load reduction is a function of the number of stories carried by a member or is dependent on whether the load is coming from a single level or from more than one level. Where d is floor dead load. The reduction formula has two reduction terms.

Live load reduction is a reduction in live load that contributes to the actions on a member. L r l o r 1 r 2.