Pumice is somewhat porous and is lighter than most aggregates.
Green roof growing medium thickness.
But remember more the.
The substrate is usually an aggregate mixed with about 20 organic material.
Green roofs on small 1 8 by 2 4 m buildings consisting of a conventional flat roof covering a root barrier a 12 mm thick enka drainage layer 89 mm of growth medium 25 mm of porous expanded.
These aggregates make a good basis for a growing medium.
About 4 inches of growing medium is the minimum requirement for both green roof and living wall.
These extensive green roofs generally have 80mm of substrate.
These materials are available throughout the west coast of north america.
Add a couple of inches for the drainage waterproofing root barrier etc.
Extensive green roofs substrate based green roofs.
To make this process work various green roof layers are created to give it the most effective and solid chance of being successful.
The basic anatomy of a green roof consists of vegetation growing medium filter membrane drainage layer waterproof root repellant layer roofing membrane support for plantings above thermal insulation vapor control layer and structural roof support.
The layers of a green roof are as follows from top to bottom.
A green roof or living roof is a roof of a building that is partially or completely covered with vegetation and a growing medium planted over a waterproofing membrane it may also include additional layers such as a root barrier and drainage and irrigation systems.
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.
The substrate sits on the green roof system filter sheet drainage layer protection layer.
Green roofs are differentiated by the depth of the growing medium as this directly relates to weight the primary structural concern.
All three types of roofs require specific layers of roofing materials not found on regular roofs.
The vegetation layer consists of sedums and wildflowers.
For the best green roof medium the growing media should contain the following.
Intensive roofs are those greater than 4 inches in thickness with some as deep as 2 feet or more making a wide variety of plants including bushes and even small trees possible.
For an extensive green roof growing substrate the infiltration rate should be 1 0 mm min or 60 l m 2 h for an intensive green roof infiltration rate s should be 0 6 mm min or 36 l m 2 h.
So about six inches of minimum provision is required.
The soil is usually not more than 5 deep and is sometimes contained by a tray system which provides a barrier to excessive growth protects the roof membrane and also interlocks the.
Container gardens on roofs where plants are maintained in pots are not generally considered to be true green roofs although.
