In 2004, Ford Motor Company integrated cutting-edge environmental design into its manufacturing facility with the construction of the Ford Dearborn Truck Assembly Building. The 1.15 million-square-foot facility was constructed at the Ford Motor Company Rouge River Industrial Complex in Dearborn, Mich. An environmentally friendly design was an integral part of the project from the outset. Ford Motor Land engaged renowned environmental architect William McDonough to serve as the consulting architect with the project architects ARCADIS Giffels. The plan was to design a building that would allow the automobile manufacturer to produce vehicles efficiently and profitably in an environmentally friendly, modern and versatile manufacturing facility.
The resulting design not only succeeded in achieving the initial objectives, but it has become a template for future Ford Manufacturing facilities. The design allowed the building to achieve LEED status through the use of structural steel, natural lighting and the green roof assembly. Structural steel contributes to buildings’ sustainability because it is nearly 100 percent recyclable. Steel is one material that can be recycled repeatedly without losing quality. The structure was erected using nearly 8,500 tons of structural steel.
Natural lighting was also implemented in the design to reduce large-scale energy usage. To help provide natural lighting into the interior areas, a total of 36 gabled skylights (each 12 feet 6 inches by 25 feet) were installed in the roof of the manufacturing area. Ten monitors measuring 33 feet 4 inches by 100 feet were installed over the employee mezzanine. These installations bring natural light into the building and reduce the need for artificial light during the daylight hours. Photo sensors were installed in the artificial lighting to brighten or darken the lights as needed. This allows for an even distribution of light throughout the facility when the sun is in the clouds. To further enhance the natural lighting, all of the exposed steel was painted a bright white to provide reflectance and to lighten the spaces.
When the Ford Dearborn Truck Assembly Building opened in 2004, it had the distinction of housing the largest garden roof assembly in North America - and perhaps the world. The 454,000-square-foot (about 10.5 acres) living roof area was designed to control the water runoff from the roof area to the aging underground infrastructure. The actual roof construction was completed in 2002. As the roof enters its sixth year, we thought it would be a good idea to find out how the industry’s most famous vegetative roof has performed to this point.
The roof construction was completed by applying a conventional roof system over the structural metal deck. The roof construction consisted of a modified bitumen roof membrane set over rigid insulation. The SBS modified membrane consisted of a base ply and cap sheet set in hot asphalt. Isocyanurate insulation was fastened through the galvanized metal deck and cover board insulation was set in hot asphalt over the Isocyanurate layer.
The garden roof assembly consisted of protection board and a thin, four-layer growth media/drainage mat system. A low-maintenance perennial ground cover called sedum was placed over the membrane. Members of the design team traveled to Germany prior to the roof design to inspect garden roofs completed using systems designed by Xero Flor, an international firm specializing in green roofs and other related systems that were used on this project.
The primary intent of the living roof application was to filter storm water and minimize the storm water runoff. The total building size is 1.15 million square feet, and it was determined that the capacity of the runoff would exceed the capabilities of the complex’s aging sewer system, which was built in the early 1900s. The cost of a new sewer system would have been prohibitive and could have jeopardized the entire project.
Announcement of Green Roof Study
Roger Gaudette, the Director of Asset Management for Ford Land Corporation, has assembled a team of initial project participants to conduct a post-construction study of the roof’s performance to this point. Gaudette served as Ford Land’s point man and liaison between the designers and contractors during the facility’s development and construction phases. He was involved with the living roof from the project’s outset in 1999 and had input in materials and application methods applied in final construction.
Due to the overwhelming number of requests for information and data on the sustainable aspects of the living roof assembly, Ford has decided to conduct this study to provide the industry with a review of the roof system’s performance. There has also been some misinformation presented in some construction industry journals, which claimed the roof system has had numerous problems; this information was not substantiated by building occupants.
Gaudette chaired the first meeting in December 2008, with a follow-up meeting scheduled for March 2009. The goal of the study is to provide information on the roof’s performance from a waterproofing and living roof perspective.
Xero Flor, the manufacturer of the applied green roof system, has agreed to work with Michigan State University to develop testing and review criteria to determine the current diversity of the plant life and what level of irrigation is required. The group will also determine if the original sedum depth was sufficient and if there are any signs of shrinkage to the green system from the aluminum membrane strips. Maintenance and long-term care methods will also be determined.
Paragon Roofing Technology, the project quality assurance roofing consultants, will conduct a study of the membrane roof system to determine existing roof service life and compare roof performance in covered and uncovered areas. Testing will be conducted in accordance with ASTM standards for modified bitumen roof systems. The test cores will be extracted and repaired by Christen Detroit, the original roof applicator.
Ford’s environmental department will work with Giffels to develop a storm water study to determine water runoff levels. Giffels will also assist Ford’s Energy department with a study of the systems energy savings.
The testing will begin in the spring of 2009. Ford plans to publish the results of the study as a way to provide sustainable data to the construction industry. Stay tuned to Roofing Contractor for the study’s results.