Green Roof Technology

Green roof applications are appropriate for residential, farm, industrial, and office buildings.  Depending on latitude, expected snow and rain load and building construction, additional reinforcement may or may not be necessary.  Typically, a green roof consists of a thin (2 – 3 inches) layer of soil and a drainage layer, applied directly to a roofing membrane.  For sloped roofs, baffles may be necessary to retain the soil.  Green roof plants are typically short perennials and succulents, including such varieties of Sedum or Delosperma.  These plants will quickly cover the soil and prevent erosion, retain rainwater, and provide insulation and respirative cooling.

Advantages of Green Roofs

According to studies conducted at Penn State University, in Europe, and elsewhere, green roofs can provide significant advantages in many applications.

• Green roofs retain rainwater, thereby reducing the requirement for drainage ponds in business parks and minimizing storm drain requirements.  Depending on the typical weather patterns, up to 90% of an area’s typical rainfall can be absorbed by a green roof.
• Green roofs can reduce the surface temperature of a roofing membrane significantly, up to 40 degrees Fahrenheit on hot sunny days.  As a result, life expectancy of the membrane can reasonably be expected to double. 
• Green roofs cool the surrounding air.  In fact, by respirating the retained water, they can cool the roof and surrounding air significantly.  This microclimate can significantly reduce adverse “urban heat island” weather patterns. 
• A green roof will provide substantial noise insulation.
• A living roof provides additional land area, allowing for more biological diversity.
• Green roofs can absorb airborne toxins and respirate oxygen into the air.

Green Roof Plant Materials

Many varieties of plants are appropriate for green roofs, depending on weather conditions, temperature ranges, and many factors relating to the structure and roof construction itself.  Popular species include Sedum, Delosperma, and varieties of grasses and mosses. 

At Green Roof Plants, we propagate many hundreds of species of plants for green roof projects in North America.  We prefer to work collaboratively with architects and designers to determine a plant list that would be optimal for each project.

Research and Development

Since a green roof is made up of many components, it’s important to consider the complete system of all the roofing components as well as environmental factors.  At Green Roof Plants, we are continuing to work with plant suppliers, roofing material manufacturers, researchers, architects, and soil & aggregate providers to ensure we can provide the ideal plant stocks for each installation.  We have test plots for assessing various plant varieties in multiple installation environments.  Click HERE to go to our R&D Pages

Emory Knoll Farms, Inc.

3410 Ady Rd.

Street MD  21154

410-452-5880