Lastly strategies utilizing green roofs within the context of the.
Gree roof live load.
Developed by fm approvals llc fm standard 4477 is the approval standard for vegetative roof systems.
Where snow isn t a problem the live load can come from people working on the roof and any equipment they.
Structural loads weight of green rooftops.
Arch 331 note set 13 1 s2014abn 2.
Astm e2397 is the established standard procedure for determining the dead and live loads associated with green roof systems.
It evaluates green roof performance related to fire foot traffic resistance and water leakage.
Live loads seismic loads wind effects load combinations serviceability concerns and astm standards is provided.
The second trussed roof is designed for a dead load of 160kg m 2 and a live load of 40kg m 2.
The dead load of a green roof assembly should be determined on a project specific basis because growth medium composition varies from job to job.
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 see section 1607 13 2 for reductions in minimum roof.
Saturated with water the weight can increase by as much as 35 to around 100 to 110 pounds per cubic foot.
In july 2011 the liveroof hybrid green roof system became the first to be fm approved according the fm standard 4477.
Building codes may vary so it is important to determine the local requirement for live loads and dead loads and to understand how the green roof being built relates to weight requirement.
One cubic foot of dry agricultural dirt or loam typically used for a green roof weighs between 75 and 81 pounds.
The entire green roof assembly including plants and the water required to saturate the growth media is considered part of the dead load of the structure.
The live load on a roof is the weight of any temporary objects on the roof.