Residential Roof Live Load

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

Residential roof live load.

Axial forces from snow loads and roof live loads should usually not be considered simultaneously with an extreme wind load because they are mutually exclusive on residential sloped roofs. This issue of live load vs. Minimum uniformly distributed live loads adapted from sei asce 7 10. Also whether live load reduction has been applied.

Minimum design loads for buildings and other structures location uniform load psf kn m2 apartments see residential access floor systems office use. Further in most areas of the united states design winds are produced by either hurricanes or. Design loads for residential buildings 3 1 general. As a result the live load dead load and distribution of forces are different.

1603 1 2 roof live load. The roof shall be designed for the live load indicated in table r301 6 or the snow load indicated. The roof live load used in the design shall be indicated 780 cmr 1607 11. Cold weather loads snow typically applied to exposed roofs or decks ground snow load commonly 10 psf usually roof live load governs unless snow drifts are considered frost heave condition where soil under footing freezes and exerts upward movement on the foundation bottom of footings must be below frost depth to avoid this.

0 9d 1 0w a load factor of 1 6 when adding to load 7. 1607 12 1 distribution of roof loads. 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. 1603 1 3 roof snow load.

Applied shall be indicated. 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 ground snow load p gf and the flat roof snow load p and if applicable the sloped roof snow load p s shall. Since it is possible to use the attic for storage the live load of the attic floor is set at 20 psf according to code.

Unlike the trussed roof live load and dead load of the rafters and ceiling joists must be accounted for as separate systems.