Green Roof Growing Medium

When saturated these layers can weigh in at more than 100kg per square metre or 20lbs per square foot.

Green roof growing medium.

Lightweight volcanic aggregate such as pumice or lava. For the best green roof medium the growing media should contain the following. Commonly referred to as growing media or soil substrates the growing medium used is an essential part of the green roof system. Green roof growing medium is composed of mineral aggregates and only a small amount of organic material.

Green roofs are made up of several layers typically a waterproof root barrier layer to protect the roof a drainage layer water retention mat then the growing medium and vegetation. Growing medium is not the same material used for a house plant or a garden. Quality control of the aggregate. Greater water holding capacity.

Green roofs designed for biodiversity biodiverse green roofs green roof designed for biodiversity basel switzerland. These materials are available throughout the west coast of north america. Pumice is somewhat porous and is lighter than most aggregates. These aggregates make a good basis for a growing medium.

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. However the factors allowing for a lightweight roof can create a high stress environment for plant material. Careful consideration and planning is required during the design phase of a green roof build and a local growth expert should be consulted in order to develop the best system for your needs. A green roof system is an extension of the existing roof which involves at a minimum high quality water proofing root repellent system drainage system filter cloth a lightweight growing medium and plants.

During dry spells the growing medium can shrink leaving it vulnerable to weeds. Green roof substrate has been researched developed blended and improved over several decades. Over the years the brown roof idea developed into the green roof designed for biodiversity. Over a 100m2 green roof with 10cm depth of growing medium the weight saved by using substrate instead of soil is considerable.

Then a yearly haircut and occasional fertilizer as indicated by a soil test is all that s needed to keep the green roof fit and trim. Green roof systems may be modular with drainage layers filter cloth growing media and plants already prepared in movable often. In general the bulk of the water storage in a green roof buildup is in the growing medium. Types of green roofs.

The extensive green roof lightweight cost effective and probably the most popular of the green roofs. This of course can be reflected in the cost of building materials.