Live Load Of A Green Roof
This stems both from containment challenges but also from the extreme difficulty in managing soil moisture on a roof of such pitch.
Live load of a green roof. Both of the main international green roof organizations the german fll and north america s green roofs for healthy cities agree that green roofs should not be applied to roofs with slope of greater than 40 degrees. 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. Structural loads weight of green rooftops. The second trussed roof is designed for a dead load of 160kg m 2 and a live load of 40kg m 2.
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. Saturated with water the weight can increase by as much as 35 to around 100 to 110 pounds per cubic foot. A traditional green roof can exert a load of up to 250 kg per m2 and that inevitably means a strong building is required to support the weight. In older buildings or new build this may require costly structural reinforcement which in some cases may prove prohibitively expensive.
An analysis of tree loading sloped roofs seismic anchorage of green roofs and recommended structural design specifications and strategies will also be presented. The live load on a roof is the weight of any temporary objects on the roof. Astm e2397 is the established standard procedure for determining the dead and live loads associated with green roof systems. 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.
Live loads seismic loads wind effects load combinations serviceability concerns and astm standards is provided. The venny green roof has shallow substrates on two types of roof the first roof is on shipping containers and is designed for a dead load of 250kg m 2 and live load of 100kg m 2. Lastly strategies utilizing green roofs within the context of the. One cubic foot of dry agricultural dirt or loam typically used for a green roof weighs between 75 and 81 pounds.
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.