Ground snow load might seem somewhat confusing until you read the basic premise that is identified in irc section r301 6 which states.
Live loads of a sedum roof.
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.
The roof shall be designed for the live load indicated in table r301 6 or the snow load indicated.
This lightness means most buildings have a comfortable load bearing capacity that is sufficient and architects can even plan green roofs where it had not been possible before such as on lightweight metal constructions.
As noted in the draft astm standard standard guide for selection of roofing waterproofing membrane systems for vegetative green roof systems the introduction of a vegetative roof system to a new or existing structure has an effect on both the live and dead loads.
The live load on a roof is the weight of any temporary objects on the roof.
It has areas of deep and shallow substrate and is designed for a dead load of 300kg m 2 and a live load of 300kg m 2 on the decking and walkway mesh areas and 150kg m 2 on the planting area.
This issue of live load vs.
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.
An extensive green roof or sedum roof is a roof with vegetation that is more or less self perpetuating and that can further develop and maintain itself.
Roughly speaking extensive green roofs have a substrate thickness of between 4 and 15 cm and a weight of 30 to 220 kilo per m2.