Greenroofs.com Project of the Week: 4/25/11
U.S. Tax Court
Washington, DC, USA
5,500 sf. Greenroof

Year: 2008
Owner: U.S. General Services Administration
Location: Washington, DC, USA
Building Type: Municipal/Government
Type:  Extensive
System: Single Source Provider
Size: 5,500 sq.ft.  
Slope: 1%
Access: Inaccessible, Private

Project Description & Details

The United States Tax Court, one of a number of notable General Services Administration’s greening projects, was recently reroofed with a Barrett Company extensive assembly, adding to the growing federal green roof inventory within the Capitol District.  The green roof initiative is reducing the storm water runoff volume while providing the many other environmental contributions that green roofs are known to provide including increased roofing longevity, carbon dioxide-oxygen exchange, reduced interior noise pollution and reduction of the urban heat-island effect.

The project actually has two wings with three green roofs totaling 5,500 sf of vegetated area: two green roofs on the north wing and one on the south wing.  Two succulent plugs per sf were planted including Sedum album; Sedum spurium ‘Fuldaglut’; Sedum kamtschaticum; Sedum sexangulare; Sedum reflexum ‘Blue Spruce’; Delosperma nubigenum, and Sedum rupestre “˜Angelina’.  An erosion control mat was placed on top of the extensive growing media.  Not publicly accessible, the U.S. Tax Court’s Greenroof-Roofscapes ® provides a visual delight to its high-rise neighbors.

Designers/Manufacturers of Record

Waterproofing & Greenroof System: Barrett Ram-Tough 250DM -“Greenroof-Roofscape ®” Extensive Green Roof
Architect: MTFA Architecture, Inc.
Waterproofing & Greenroof-Roofscape ® Installer: Cole Roofing Company, Inc.
Greenroof Installation Management & Maintenance: Greg Long, Capitol Greenroofs

Although the square footage for the vegetated area is 5,500 sf, Barrett Company provided a total area of 21,300 for the hot fluid applied roofing area.  Cole Roofing was brought in as Barrett Company’s Greenroof-Roofscape ® Installer.

Here are some photos of the December, 2008 installation:

As you can see from these photos a gravel bucket was hoisted to the roof and fall protection fencing was set up around the receiving area.  The growing medium was compacted using a 200 lbs. rolling drum, and 2″x10″ boards were used to screed it to ensure proper depth.  Then the growing medium was saturated and compacted to reduce wind erosion.  And finally, an erosion control mat completed the plantings.

Here’s what the roof looked like right after, in December 2008 and then the following season in late April and May, 2009:

Remember that planning in a busy downtown district can be tricky, but extremely important for all of the material material providers on a project.  Greg Long, seen below, says:

“Staging the materials is often the most difficult part of the project and minimizing the amount of times that you move material often determines whether a project will be profitable. “

It sounds like everyone is pleased with the way the project has fared.  Referring to Tim Barrett and Greg Long of Capitol Greenroofs, Bill Cole of Cole Roofing says:

“Greg and Tim have been great.  We hired Greg to oversee our men during the installation and then continue the maintenance.  He has done an excellent job.”

Did we miss something?  We’d love to hear from you!  Click  here to see more information about this project in  The International Greenroof & Greenwall Projects Database.  See how you can submit yours  here.

Love the Earth, Plant a Roof!

~ Linda V.