Roof Live Load Reduction

Live load reduction is a reduction in live load that contributes to the actions on a member.

Roof live load reduction.

Except for uni form live loads at roofs all other minimum uniformly distrib uted live loads lo in table 1607 1 are permitted to be reduced in accordance with section 1607 10 1 or 1607 10 2. 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 commentary in asce 7 05 c4 about roof live load reductions explains the anticipated difference in use of roof areas vs. Commentary in asce 7 10 c4 8 about roof live load reductions explains the anticipated difference in use of roof areas vs.

The reduction formula has two reduction terms. 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. On a roof with a slope greater than 4 to 12 the live load limit is typically adjusted downward from 20 psf to 15 psf to allow for the relatively greater dead load on the steeper roof. One for the tributary area supported by the structural element r1 and the other for the.

Likewise roof live loads in the hong kong building regulation can be reduced as a function of the slope. The reduction formula has two reduction terms. Hence the magnitude of the roof live loads should be specified as for a flat roof and the program allowed to make the reduction based on the slope of the framing. 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.

1607 10 reduction in uniform live loads. Roof live load reduction. R1 1 for at less than or equal to 200 psf r1 1 2 0 001 at for between 200 psf and 600 psf r1 0 6 for at greater than or equal to 600 psf r2 1 for f less than or equal to 4 r2 1 2 0 01 f.