Green roofs or living roofs have become popular over the years.
Grass depth of soil green roof.
Planting areas with restricted soil depth or restricted soil volume are notoriously prone to drying out quickly but don t be fooled into thinking you don t need to address drainage.
There are two types of green roof.
When designing a green roof there are several factors to take into consideration.
Whether your planting bed is in the lawn green roof or a planter proper drainage is crucial.
Shrubs to one metre in height are best used in substrate depths of 250 mm or more.
Increasing the substrate depth and irrigation will also increase the range of plants that can be used successfully.
Rooftop lawns rooftop lawns are semi intensive green roofs with a total depth of at least 8 inches.
Small shrubs provide cover display and habitat values and often form the bulk of plantings used on green roofs with deep substrates.
It is also important to factor in the type and lifetime of the roof membranethat will be used.
This rooflite soil system supports lawn grasses that require deeper root space and thrive on a soil with plenty of finer particles and the precise amount of organic matter.
This is especially true of intensive green roofs which can have soil that is two feet deep or more.
The lite system is typically used on retrofit projects when the roof is engineered with only 15 to 17 pounds per sf for the green roof component.
An aqua drain carries away excess water.
Intensive roofs which are thicker with a minimum depth of 12 8 cm 5 1 16 in and can support a wider variety of plants but are heavier and require more maintenance and extensive roofs which are shallow ranging in depth from 2 cm 13 16 in to 12 7 cm 5 in lighter than intensive green roofs and require minimal maintenance.
This is because they provide ecological benefits aesthetic value and creative urban architecture.
400cm3 green roof substrate weighed 800g 400cm3 garden soil weighed 1020g in other words around 20 more over a 100m2 green roof with 10cm depth of growing medium the weight saved by using substrate instead of soil is considerable.
Its soil depth is a full 2 inches enough to support many low growing succulents and a limited number of accent plants.
Extensive green roofs these generally require a 5 15cm 2 6in depth of growing medium that can consist mainly of lightweight inorganic materials such as perlite leca sand rockwool and crushed tiles or concrete.
This of course can be reflected in the cost of building materials.
It is generally not recommended for hot climates.
Green roofs with turf are lush usable spaces.
The structural engineer must factor in the weight of completely saturated soil since the plantings and the soil will hold a significant amount of water.
Soil structure for green roof media.
