Roof Live Load

Live roof load w wind load s snow load e earthquake load r rainwater load or ice water load t effect of material temperature h hydraulic loads from soil f hydraulic loads from fluids.

Roof live load. Chapter 3 design loads for residential buildings. Load limits on the roof of a building dead loads. The uniform design live load in unoccupied landscaped areas on roofs shall be 20 psf 0 958 kn m 2. It the roof is subjected to snow load it should be designed for the actual load due to snow or lot the live loads specified in table 1 3 whichever is more severe.

For a larger map with greater detail refer to asce 7 98. D dead load l live load l. The north zone middle zone and the south zone are identified on the roof load zone map above. The uniform design live load for occupied landscaped areas on roofs shall be determined in accordance with table 1607 1.

In areas where the ground snow load is less than 15 psf the minimum roof live load refer to section 3 4 is usually the controlling rgavity load in roof design. Actual load due to snow will depend upon the shape of the roof and its capacity to retain the snow. Roof and floor live loads are produced during maintenance by workers equipment and materials and during the life of the structure by movable objects such as planters and people. Roof load live load design is affected by the shape of the roof whether it is flat curved or pitched.

Where uniform roof live loads are reduced to less than 20 psf 0 96 kn m2 in accordance with section 1607 12 2 1 and are applied to the design of structural members arranged so as to create continulty the reduced roof live load shall be applied to adjacent spans or to alternate spans whichever produces the most unfavorable load effect. Where snow isn t a problem the. Using the term live loads when referring to roofs might make you scratch your head initially because roofs unlike floors aren t asked to bear the weight of things such as furniture and occupants of a home what you would normally think of as a live load. Minimum design live load can be found in asce 7 table 4 1 or ibc table 1607 1.

The live load on a roof is the weight of any temporary objects on the roof. This downward imposed load on the home is also known as the snow load. Roofs of buildings used for promenade or incidental assembly purposes shall be designed for a minimum load of 400 kg m2 4 kn m2 or heavier it required. And each case shall be treated on its own merits.

Loads used in design load equations are given letters by type.