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Please read about The Barrett Company in The Greenroof Directory here.

The Crystal Rock project is believed to be the first green roof successfully installed in Northern Montgomery County, MD on an office building. The project was driven by Therrien Waddell Construction Group (TW) with prime consideration given to the economics of building ?green?. According to the President, Jerry Therrien, the ?greening? allowed a premium to be charged on the leased office space, offsetting much of the initial extra cost of the green roof.

According Mr. Therrien, ?green roof construction in the United States is relatively new. In order to engineer this phase of the building TW contacted and arranged to meet with Manufacturer?s Representatives and Contractors experienced in green roof system construction. It was an education from the ground up.?Before the installation of the Greenroof-Roofscapes? components, the waterproofing assembly was applied to the structural deck. The ?Ram Tough 250?, 215 mils thick rubberized asphalt membrane, polyester reinforcement and SBS protection course was supplied by GRHC Corporate Member, Barrett Company. After the waterproofing was applied, the membrane system was tested by Dave Honza of The Honza Group Incorporated, utilizing an Electric Field Vector Mapping (EFVM) test method. A watertight membrane was confirmed and the approval to proceed with the Greenroof-Roofscapes? system installation was given two thumbs up! The green roof horticultural elements were applied atop the fully warranted Ram Tough waterproofing system.

Engineered soil media consisting of a blended mix of mineral, organic, synthetic and fertile topsoil to sustain and nurture the plants was installed on top of the Greenroof-Roofscapes? drainage/retention mat. Sedums were obtained locally by Davey Tree, who used a grid planting method to ensure each plant had the recommended space around it to thrive. Today, the green roof captures the eye with a sea of reds and greens with a forest of green tree tops backing up the scenery on the horizon – – a picturesque guise for an upscale office building.The 8-12 inch sedum plants that now blanket the 28,600 square feet of roof )as of February, 2009) display a solid mass of succulent plants with a random pattern of color and height. The vegetation chosen is expected to require an inch of water a week in summer and require relatively little maintenance. During its first year, the Crystal Rock green roof lost less than 5% of its plants to birds looking for nesting materials. With such a low plant loss, it was not necessary to replant, it being thought that the existing plants will continue to thrive and the roof will be completely blanketed with sedums. They provide natural storm water management helping to reduce run-off and the amount of water that flows into the city?s storm water system. The green roof is reducing the building?s heating and cooling costs, improving the neighborhood air quality and providing a natural habitat for the local and transient winged commuters.The growing medium consisted of six inch layer of Silas Stone and Organic Mix, six varieties of sedum plant seedlings planted a foot apart. The seedlings are expected to grow to Crystal Rock Drive roof, providing natural storm water management, reducing the building?s heating and cooling costs, improve the neighborhood air quality and provide ?heat island? reduction in the surrounding community. 15,000 mixed Sedums in 72 cells were planted on July 24, 2007. Montgomery County?s new ?Green Building Law? was passed November 28, 2006 and bacome mandatory by September 1, 2008. It requires non-residential buildings over 10,000 square feet to achieve a LEED (Leadership in Energy and Environment Design) silver rating, a national benchmark for the design, construction and operation of high-performance green buildings. The Greenroof-Roofscape? can provide valuable points necessary to meet LEED requirements.


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