The 2010 Greenbuild International Conference and Expo, held November 16-18 in Chicago, drew steady crowds looking for the latest in 'green' technology, 'green' ideas and just cool 'green' stuff. And there was plenty to see, as more than 1,000 exhibitors displayed their newest and most innovative, sustainable products and services. Aegis Metal Framing was no exception, as we proudly displayed a new "twist" on an accepted technology, to rave reviews of attendees.

Vegetative roof

The concept of vegetative roofs has been around for centuries. In many Scandinavian countries, the use of sod or turf roofs on dwellings dates back to the middle-ages. During the 19th century, the United States saw extensive use of earthen materials for house and roof construction by pioneers migrating westward. More recently, vegetative roofs have been used in metropolitan areas, like Chicago, as a way to help increase green space within a city while fully utilizing the valuable real estate underneath.

Modern vegetative roofs, or Green Roofs as they are commonly known, use a specialized, lightweight growth medium designed to help native plants thrive on the rooftop of large commercial and institutional structures. These modern green roofs help reduce rain water runoff, greatly reducing strain on overworked storm water sewer systems. Green roofs also have excellent energy and sound insulation properties and as such can offer attractive energy savings.

The United States Green Building Council offers the following LEED credits specific to storm water design and vegetative roofs.

  • LEED® Storm water Design: Quantity Control (SS Credit 6.1), 1 point
  • LEED® Storm water Design: Quality Control (SS Credit 6.2), 1 point
  • LEED® Landscape & Exterior Design to Reduce Heat Islands, Roof Surfaces(SS Credit 7.2), 1 point.

Additional points may be awarded for use of recycled materials, innovation in design, reuse of gray water for irrigation, proximity of material manufacturing, proximity of raw materials and energy efficiency.

Given this long history and level of recognition for vegetative roofs within the green building community, you might be asking, "what is this great 'new twist' to which you are referring?" Well, think of all those wonderful benefits of a vegetative roof, on a 5/12 pitch! That's right, whereas historically green roofs have been mostly flat or only gently sloped, now a vegetative roof can be sloped, thanks to Ultra-Span cold formed steel trusses.

One of the primary functions of a roof is to keep the contents of the structure dry. The most reliable method to keep water from leaking into the roof is to drain it off quickly. And the preferred method to create a 100% non-combustible sloped roof is with cold-formed steel trusses.

High recycled content (in excess of 60%) Ultra-Span trusses continue to gain popularity within the sustainable construction community. These building components are assembled in a factory environment, eliminating jobsite waste and improving overall construction efficiency. Quick installation of light weight cold-formed steel components allows a faster "close in" of the structure, compared to more traditional construction methods like masonry or structural "red iron".

To learn more about, sloped, vegetative roofs, feel free to contact Aegis Metal Framing or our vegetative roofing partner, Tremco,