army depot adopts camo roof?

From the Pocono (Pennsylvania) Record
01 October 2006

Tobyhanna Army Depot environmentalists believe they are the first to plant a garden on the roof of a Department of Defense building. Funding from the Joint Services Initiative allowed depot officials to install a vegetative green roof on one wing of the headquarters building this summer.

The Joint Services Initiative provides funding for projects that would save money, positively impact the environment and be transferable across the services. The demonstration project is part of a plan to improve the energy performance of buildings, reduce storm water runoff, extend roof life and contribute to a healthier environment.

A green roof, as the name implies, is a roof covered in plants. Workers covered the 14,141-square-foot roof space with about 1,500 pre-planted modules — recycled black plastic trays measuring 4 feet long, 2 feet wide and 4 inches deep. Sixteen plants were placed in each module at the nursery and cared for until they were shipped here.

"We asked for sedum perennials because they are drought and flood resistant, retain water, and have shallow root systems. Sedum is a low-maintenance shrub that does well in this climate," said Mike Parrent, pollution prevention program manager, Industrial Risk Management Directorate.

The green roof technology offers a flexible and modular design that can be adjusted and rearranged after installation. Modules can be moved to deal with a maintenance issue and then put back in place.

"Anytime you can save the government money and cut back on energy consumption, especially in this day and age, it's a plus," Didier said. "Research suggests we can expect up to a 30-percent reduction in energy costs down the road."

Reports also claim a green roof will extend the life of the existing rubber roof covering. Didier indicated the rubber roof is reported to last up to three times longer than the stone ballast it replaced. The stone was removed and will be used in a variety of depot projects.

"Ultraviolet rays break down the rubber and sealants on ballast-type roofs," said Don Rusnak, engineering technician for the Public Works Directorate. The green roof modules should provide better protection once the plants spread out and cover the area, he said.

Shortly after the project was completed, Didier noticed a marked difference in temperature from the green roof and the control roof. At the time, he estimated it was 80 degrees on the green roof and close to 120 on the rock ballast [control] roof.

Soil and dense vegetation cover have a great insulation value, according to the Maryland Department of Environment Web site. Working together, the two elements enhance the energy efficiency of a building and reduce noise. Department documents also noted that the vegetation cover protects the roof from direct sun exposure and prevents the roof surface from heating up.The growing media, plants and layers of trapped air in a green roof system serve as sound insulators. The modular system can be installed on any new or existing roof surface in good condition with structural capacity.

EMD personnel worked closely with the Public Works Directorate's Engineering Division, which manages all depot facilities to include one million square feet of flat roofs.