Green Roofs are Sprouting Up All Over Despite a Weighty Problem

While the history of green roofing may still be somewhat controversial – some writers point to sod roofs of Iceland and Ireland, some to the Hanging Gardens of Babylon, and others to pit houses among the First Peoples of the Southwest United States – even so, statistics show that contemporary green roof use enjoys consistent and global growth today.
What is a green roof?
At a very basic level, green roofs are similar to container gardening. Only, these containers are on top of your house instead of in your backyard – and instead of barrels, lightweight plastic mats are used. The lowest layer is the man-made roofing material itself, then a waterproof barrier, then a layer of insulation and a drainage system are installed on top of that. Finally a system of mats filled with growing medium and plants is fitted together and installed on top. Up there, access to plenty of sunlight and rain water encourages the vigorous and healthy growth of the plants.
Green roofs come in three flavors:
Extensive green roofs: in which less than 6 inches of growing medium is used;
Intensive green roofs: in which more than 6 inches of growing medium is used;
Hybrid roofs: which include elements of both of the above and can accommodate plants of varying sizes.
But how “green” is it?

On the surface, business seems a far cry from nature. But as the old song lyric goes, “That ain’t necessarily so”. The late Ray Anderson who founded Interface Carpet used a discarded mountain of ripped out carpet as his inspiration and gave birth to the recycled carpet industry by seeking a better way. He believed there was a way to make business thrive on this planet without the ecological and social impacts that make our current “take-make-waste” system obsolete.





