A collaboration of DC Greenworks, Casey Trees, and Blake Real Estate, the 3,500 sq. ft. greenroof located 13 stories above 1425 K Street is a showcase to accelerate the adoption of greenroof technology in the Nation’s Capital. Monitoring equipment installed on the greenroof, and on an unplanted control area, is expected to document a significant reduction in storm water runoff and rooftop temperatures. DC Greenworks is the technical lead and general contractor for installation and trained a workforce team of young adults from Covenant House Washington, a nonprofit youth services agency serving at-risk youth.

The project was supported by grants from the Chesapeake Bay Small Watershed Grants Program administered by the National Fish and Wildlife Foundation, and by the Watershed Protection Division of the DC Department of Health. Training for Covenant House youth was supported by the US Environmental Protection Agency and Bridges to Friendship. This greenroof was awarded the Washington Business Journal’s “Best Real Estate Deals of 2004” winning in the category for Sustainable Growth & Environmental Impact.

Several steps were required to prepare the roof for 33,000 pounds of engineered soil and 9,730 low-growing succulent plants comprised of 11 species of sedums. Following removal of the upper layers of the previous roof, a new Barrett Ram Tough 250 waterproof membrane/root barrier was installed in conjunction with EFVM electronic leak detection system that showed the system to be waterproof prior to planting. On top of the new membrane a two-inch layer of polystyrene insulation was replaced, topped by a layer of geo-textile filter fabric, and an inch-thick JDRain greenroof drainage mat.

Greenroof media was spread three inches deep across the roof and topped with a loosely woven jute mat to hold it in place until the plants are fully established in one to two years. The plants were hand-planted in clusters to form a mosaic of variety, color, and texture. After planting was completed, the fully planted roof was again tested for leaks and passed with flying colors.The green roof growing media used for this project was supplied by Skyland USA, LLC, the creators of rooflite. Rooflite is the first and only standardized green roof growing media in North America being sold under an independent brand name. Rooflite green roof media products meet or exceed all of the current standards of both the ASTM and FLL. The components of rooflite are guaranteed to be of the highest quality while at the same time being price competitive.

Additionally, the current line of rooflite green roof media products contain HydRocks calcined clay, which is recognized as the best light weight aggregate on the market today. Lastly, the organic components of all rooflite green roof products have been tested under the United States Composting Council’s, Soil Testing Assurance (STA) program which gives you the added assurance that you are using the best product available.