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.

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

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. 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. Where l r shall not be less than 12 psf and not more than 20 psf. 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.

The live load on a roof is the weight of any temporary objects on the roof. 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. 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 reduction.

The commentary in asce 7 05 c4 about roof live load reductions explains the anticipated difference in use of roof areas vs. The reduction formula has two reduction terms.