However the factors allowing for a lightweight roof can create a high stress environment for plant material.
Green roof growing medium.
Greater water holding capacity.
Quality control of the aggregate.
During dry spells the growing medium can shrink leaving it vulnerable to weeds.
This of course can be reflected in the cost of building materials.
Green roof growing medium is composed of mineral aggregates and only a small amount of organic material.
For the best green roof medium the growing media should contain the following.
Sarah and scott can irrigate this roof with a self coiling garden hose threaded into the second floor bathroom sink faucet.
The extensive green roof lightweight cost effective and probably the most popular of the green roofs.
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.
Types of green roofs.
Ensuring the growing medium is right for the type of.
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.
Lightweight volcanic aggregate such as pumice or lava.
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 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.
These aggregates make a good basis for a growing medium.
Green roof substrate has been researched developed blended and improved over several decades.
Green roof systems may be modular with drainage layers filter cloth growing media and plants already prepared in movable often.
Commonly referred to as growing media or soil substrates the growing medium used is an essential part of the green roof system.
Growing medium is not the same material used for a house plant or a garden.
In general the bulk of the water storage in a green roof buildup is in the growing medium.
When saturated these layers can weigh in at more than 100kg per square metre or 20lbs per square foot.
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.
Over the years the brown roof idea developed into the green roof designed for biodiversity.
Pumice is somewhat porous and is lighter than most aggregates.
Traditional soil is heavy and packs tight after repeated rains reducing water retention and aeration for plant roots.
