Green Roof @ Swarthmore’s Lang Performing Arts Center

Continuing our strong commitment to sustainable construction, we recently completed work on a new green roof system at the Lang Performing Arts Center at Swarthmore College in Pennsylvania. This system encompasses five different roofs of different heights and sizes across the entire building. Plant materials included rolled mats as well as plugs and cuttings.

Since 2007, we have teamed with Furbish Company of Baltimore to install over a quarter million square feet of living roof space. Over the course of these intricate projects, Alan Graham Construction Manager for the Challenge Program has developed valuable expertise in the green roof installation process. The Challenge Program trainees involved in these projects have provided critical labor while acquiring desirable green industry skills.

Below is a listing of various green roof projects we've completed in the area. They range from small applications to larger multi-roof installations and include both commercial to residential buildings.

         Barclays Bank – Wilmington, DE
   Interfaith Community Housing – Wilmington, DE
       Queens Botanical Garden – New York, NY
         PECO Building – Philadelphia, PA (maintenance only)
   Private residence – Bainbridge Street, Philadelphia, PA
           Delaware Courthouse – Rodney Square, Wilmington, DE
           Swarthmore Performing Arts Center – Swarthmore, PA

Green roofs are often installed to reduce energy and maintenance costs. The plant material acts as both insulating material and a protective cover for the waterproof roof membrane. The environmental effects of living roofs are remarkable. They reduce impervious surfaces decreasing urban runoff and improving water quality. Additionally, the heat island effect common in urban areas is significantly reduced.

The installation process is quite labor intensive, involving a layered ‘lasagna’ approach:

          Plants – specialized selections adapted to hot, dry conditions and thin soil layers
      Growing Medium – typically lightweight pumice and expanded stone and very little organic material
          Filter Fabric – barrier between growing medium and drainage layer
      Retention and Drainage Layer – holds rain water and allows any excess to drain from the building
          Protection Fabric – prevent punctures within waterproof membrane from drainage material.
      Waterproof Membrane – prevents roof leaks

Green roofs are a relatively new but growing phenomenon in the United States, but in Europe they’ve been incorporated in a wide-spread manner for much longer. From sod roofs that have been around for centuries to more modern roofs that debuted in Germany in the 1960’s they provide an impressive track record.