Green roofs typically use lightweight engineered soils with very light drainage and insulation layers.
Green roof imposed load.
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.
Photo by andrew wutke.
If a green roof is part of the initial design of the building the additional loading can be accommodated easily and for a relatively minor cost.
On roofs particularly for category h roofs imposed loads need not be applied in combination with either snow loads and or wind actions.
For example an existing roof may be designed for public occupancy 100 pounds per square foot.
One option would be to restrict access and to reallocate a portion of the design live load to the green roof.
Imposed loads may be redistributed at the architect and engineer s discretion.
Additional loading is one of the main factors in determining both the viability and the cost of a green roof installation.
Some roofs are finished with substantial.
The need for stability of the system is increased because the negative pressure forces that can develop during intensive green roofs can be safely installed on horizontal decks whereas with extensive green roofs minimum falls of 1 60 and above are preferred.
The second trussed roof is designed for a dead load of 160kg m 2 and a live load of 40kg m 2.
For dynamic loads caused by machinery see en 1991 3.
When the imposed load is considered as an accompanying action in accordance with en 1990 only one of the two factors ψ en 1990 table a1 1 and αn 6 3 1 2 11 shall be applied.
The second most common conservative assumption found in the industry is to assume that the green roof is a soil load rather than a dead load.
The minimum floor live loads shall be the greatest actual imposed loads resulting from the intended use or occupancy of the floor and shall not be less than the uniformly distributed load patterns specified in sec 2 3 4.
Floor uses and corresponding minimum imposed loads stipulated in the building construction regulations are also.
Imposed loads for design of building building works street and street works.
2 2 3 2 where a roof is to be provided with greenery the weight of soil waterproofing and drainage system and plants for greenery shall be taken.
Creating falls on a green roof.
Roofs used for roof gardens or assembly purposes.
