Stormwater Systems Benefit from Green Roofs

Publish Date: July 16, 2016
Publisher Credit: Forester Daily News

(July 16, 2016) Excerpt from an article in Forester Daily News

Green roofs – also known as vegetated or garden roofs – are key green infrastructure elements and are being increasingly recognized for their “valuable ability to absorb, reduce, and delay stormwater from reaching sewers or other grey infrastructure systems,” says Richard Hayden, garden roof product manager with Chicago-based American Hydrotech.

Green roofs work by storing rainwater in several areas of a layered assembly: in open pore spaces of the growing media and within the drainage and water retention system that underlies the growing media and plantings.

The rainwater is retained until the assembly is completely saturated, and excess water is slowly released from the roof into the site’s stormwater system. Stormwater runoff volume also is reduced because of evapotranspiration, which cools the surrounding air.

What started off as an effort to add green space on buildings for purely aesthetic purposes has morphed in a very important BMP option for handling rainwater at the point where it lands on the roof, Hayden points out.

American Hydrotech manufactures and supplies waterproofing and roofing components for projects worldwide. Its flagship product is the original hot, fluid-applied rubberized asphalt, Monolithic Membrane 6125. Originally developed in the 1960s as a waterproofing element for bridge structures in Canada, MM6125 is now used for creating green roofs.

Its seamless application makes it impervious to the effects of the wet conditions that are typical of green roofs, says Hayden. In 1996, Hydrotech introduced the Garden Roof Assembly and has since supplied waterproofing, drainage materials, lightweight growing media, and plants for more than 2,000 projects in the US and Canada.

“There are many municipalities like New York; Chicago; Philadelphia; Washington DC; and Portland, Oregon, where green roofs are being encouraged through incentives of various types,” says Hayden. “These cities are part of a significant and growing group seeking out innovative ways to minimize or slow down stormwater from reaching already overtaxed sewers.”

Recent Press

  • October 18, 2018
    American Hydrotech, a recognized leader in the vegetative roofing market, today announced the availability of the Fourth Edition of the company’s widely acclaimed Garden Roof® Planning Guide. For the last five years, updated print, online and app...
  • May 21, 2018
    American Hydrotech, a recognized leader in the development and distribution of premium waterproofing and roofing assemblies, today announced the availability of their Protected Membrane Roof (PMR) Planning Guide , a unique, new resource representing...
  • August 28, 2018
    Over the last two decades, the roofing industry has undergone some major changes, one of which is a growing recognition of the value of roof space other than keeping occupants warm and dry. Two veteran roofing professionals share their thoughts on...
  • February 1, 2018
    CHICAGO, ILLINOIS (February 1, 2018) The Chicago Blackhawks have captured the hearts of the city of Chicago along with three Stanley Cups in the last decade. The Blackhawks routinely lead the league in attendance at the United Center, and fans were...
  • October 18, 2017
    CHICAGO, ILLINOIS (October 11, 2017) American Hydrotech – a market leader in the development and distribution of premium waterproofing and roofing products and assemblies, today announced the introduction of the InstaGreen® GT-4 pre-vegetated tray,...
  • April 3, 2017
    Wind data is a critical issue to consider when building a new structure. An increase in the number of green roofs on buildings has driven a need for new wind design standards to be written for vegetative roofing assemblies. Richard Hayden discusses...