There are two types of green roof.
Graass depth of soil green roof.
Rake it until level and smooth.
Extensive green roofs are generally made up of a very thin layer of soil or other planting medium with shallow root plants like sedum mosses and grasses.
Soil structure for green roof media.
These need 10 20cm 4 8in depth of growing medium enough to support perennials but not shrubs and trees.
Roll out the moisture blanket keeping a 6 8 space around all of the edges i have read you can use old towels cloths sacks to achieve the same effect basically this is to get damp and stay damp 2.
Put 1 inch of soil or a compost soil mix on top of the underlayment system.
On smaller scale green roofs species with excessive vigour such as couch grass cynodon dactylon and kikuyu pennisetum clandestinum should be avoided.
When designing a green roof there are several factors to take into consideration.
This of course can be reflected in the cost of building materials.
Rooftop lawns are semi intensive green roofs with a total depth of at least 8 inches.
It will include a type of moisture barrier layers of insulation filter fabric and drainage protection.
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.
Green roof substrate has been researched developed blended and improved over several decades.
Shrubs to one metre in height are best used in substrate depths of 250 mm or more.
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.
Over a 100m2 green roof with 10cm depth of growing medium the weight saved by using substrate instead of soil is considerable.
Purchase an underlayment system from a green roof dealer.
Put large gravel or pebbles around the edge of the roof in the space you ve left this is.
Follow the manufacturer s instructions and install it on your roof top.
Green roofs with turf are lush usable spaces.
Put another layer of small stones over the moisture blanket 3.
Now onto the soil and compost goodness.
Green roofs or living roofs have become popular over the years.
Green roof growing media is an integral part of a functioning.
Small shrubs provide cover display and habitat values and often form the bulk of plantings used on green roofs with deep substrates.
Take a look at our pick of the best plants to grow on green roofs with a soil depth of 150mm or 15cm.
Their rhizomes can be invasive and may damage waterproofing membranes.
