Roof Live Load Reduction Example

The requirement is presented in asce 7 05 4 9.

Roof live load reduction example.

If your structure has a sloped or flat roof you still need to calculate the flat roof snow load. 0 9d 1 0w a load factor of 1 6 when adding to load 7. 1 2d 1 0e l 0 2s when h loads are present they shall have 6. Loads should be determined in accordance with this chapter.

The balanced snow load is applied everywhere where the roof structure is located. L r l o r 1 r 2. Building live load reduction recognizing that the probability of supporting a large fully loaded tributary area is small. However if the attic is intended for storage the attic live load or some portion should also be considered for the design of.

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. Where snow isn t a problem the live load can come from people working on the roof and any equipment they. Where l r shall not be less than 12 psf and not more than 20 psf. Roof live load reduction.

0 9d 1 0e effect or 0 9 when resisting the load when permanent. Roof live load reduction. Minimum uniformly distributed live loads adapted from sei asce 7 10. Roof live load may be reduced by the following equation.

After you obtain the roof slope factor from those sections in asce 7 10 the balanced design snow load for the sloped roof can easily be calculated using equation 7 4 1. The live load on a roof is the weight of any temporary objects on the roof. Where d is floor dead load. 2attic loads may be included in the floor live load but a 10 psf attic load is typically used only to size ceiling joists adequately for access purposes.

The nature of roof live load is different from that of floor live load so the approach to reducing roof live load is different from that used for floor live load. 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 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.