Extensive Green Roof Design Soil Type

Green roofs of this type can include bushes and small trees gardens and more.

Extensive green roof design soil type.

Green roof design may be considered differently for stormwater retrofits. These systems are ideal for efficient stormwater. The hydrologic and thermal performance of six different extensive green roofs and reflective and non reflective roofs in a sub tropical climate simmons et. The shallow depth results in a lighter weight roof than a traditional intensive roof garden thus reducing the cost of the building s engineered structure.

The soil depth of this type of living rafters is calculated at 3 6 inches at an average. Al 2008 urban ecosystems vol. 8 to 20 per square foot. Green roofs are not created equal.

An intensive green roof often contains more soil for the production of large roots a wider root barrier and more. Intensive systems allow the designer to create a park like setting so they are the best option for roof gardens that will be occupied. The types of plants that can thrive on an extensive green roof include many varieties of sedum semper vivum grasses mosses alpines and even some flowering herbs. Extensive green roofs have shallow soil which usually between 50 to 150 mm depending on the type of plants that are to be grown.

Extensive roofs are designed to be self sustaining and can be established on a thin layer of soil. A 2006 study by the university of michigan comparing costs of conventional and green roofs showed that on average installing a green roof costs about 22 00 sq. This style of green roof is capable of supporting 82 150 pounds of vegetation per square foot. The purpose of this type of roof is to maximize water use and moderate temperature extremes in the building while keeping the overall weight of the roof low.

Extensive green roofs have a soil depth of approximately 1 to 6 inches and usually support 10 25 lbs of vegetation per square foot. Extensive green roofs. This green roof system is highly cost efficient particularly in the long run due to almost no need to maintain a high end maintenance system. Extensive green roof an extensive green roof system is characterized of its vegetation ranging from sedums to small grasses herbs and flowering herbaceous plants which need little maintenance and no permanent irrigation system the growing medium depth for an extensive green roof system is typically 6 inches or less.

15 to 50 per square foot. Intensive green roofs require the deepest soil and have the greatest impact on the structural design but they also accommodate all types of plantings including large shrubs and trees. This variety of extensive green roof is most ideal for areas which need year round storm water management. Successful stormwater management plans will combine appropriate materials and designs specific to each site.

The design of green roofs is not limited to the examples shown within this text which focuses primarily on extensive green roofs.