Live load reduction is a reduction in live load that contributes to the actions on a member.
Live load reduction roof.
R 1 1 for a t less than or equal to 200 psf r 1 1 2 0 001 a t for between 200 psf and 600 psf.
The reduction formula has two reduction terms.
L r l o r 1 r 2.
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.
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.
The live load on a roof is the weight of any temporary objects on the roof.
One for the tributary area supported by the structural element r 1 and the other for the slope of the roof surface r 2.
Roof live load may be reduced by the following equation.
Where d is floor dead load.
The user can specify which load types are to be considered in this determination for the purpose of calculating live load reduction.
Where l r shall not be less than 12 psf and not more than 20 psf.
Roof live load reduction.
Where snow isn t a problem the live load can come from people working on the roof and any equipment they take on to the.
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.