Geosynthetics raising the (green) roof

Green roofs benefit the environment by soaking up stormwater and cooling sun-baked buildings. They also add natural beauty, style and design to normally barren spaces, bringing that ineffable environmental improvement called joy to the people who use and see the building. While green roofs are popular in Europe, they are less common in the U.S. because they can be heavy and expensive, as well as technically challenging to design and maintain. With the increase in diversity and quality of geosynthetic materials, however, green roofs may become a much more practical way to manage water and energy in modern buildings.

A successful green roof design will feature several layers of geosynthetic materials, each with a specific role. These can include acting as a root barrier, drain and filter, water retention layer, slope and root stabilizer, pre-vegetated mat for easy planting, erosion control or wind blanket. Because geosynthetics offer strength under construction duress and are lightweight, they place less structural loading on the building. Geosynthetics made of recycled materials can also contribute to Leadership in Energy and Environmental Design (LEED) certification. In areas with high-density housing, a green roof may increase a property’s value or desirability. For more information on this best management practice for stormwater management and energy reduction, visit Green Roofs, a clearinghouse for green roof information.

Information in this article was taken from “Geosynthetics: The science that makes green roofs work,” written by Allan Wingfield AIA, building materials product manager, Bonar Inc.