- Expanded Slate
- Expanded Shale
- Expanded Clay
- Volcanic Pumice
- Synthetic Fibers
- Fly Ash
- Rubber Foam
- Tire Crumbs
Hopefully we can learn from the Galapagos' near environmental tragedy.
Importantly, other green roof leaders from around the world are also looking to use of alternative materials for soils components.
Drainage is an important function expanded mined earth products help facilitate.
A recent project on the south coast of France is utilizing hard native reeds for the drainage components.
The native reeds are used locally for roofing materials and have been proven to last thirty years or longer, about the normal life of a typical roof.
Granted, thirty years life span is not the millennia expanded shale will last, but rather than a strip-mine approach or petro-fired kiln approach, the reeds represent sustainability.
And sustainability is what green roofs are really supposed to be about - creation of habitat for wildlife in the urban core, cleaning of stormwater, sequestering of carbon (instead of creating huge carbon footprints), and offering a sense of place for inhabitants.
Big industry can afford a powerful counter argument as to why strip mined and kiln fired products are really eco-friendly. But I am not big industry, nor am I an industry organization who is influenced by big industry advertising money.
I can and I will say that green roofs should be based on sustainable practices, using rapidly renewable materials, native plants and ultimately helping the world we live in rather than contributing to a Galapagos like tragedy.
Otherwise, lets just use TPO white roofing to cure heat island effect. TPO is a whole lot more cost-effective.