As the United States becomes more ecology conscious, Prospect Waterproofing Co. of Sterling, Va., is keeping up with advancements in green technology and securing its position as a leader in the installation and maintenance of vegetated roofs.

Prospect Waterproofing Co. of Sterling, Va., made green roof maintenance a priority to ensure that building owners were satisfied.


As the United States becomes more ecology conscious, Prospect Waterproofing Co. of Sterling, Va., is keeping up with advancements in green technology and securing its position as a leader in the installation and maintenance of vegetated roofs.

James N. Stamer, President of Prospect Waterproofing Company, has been a proponent of green roofs since the company was formed in 1992. With more than 350 employees and 98 percent of its work performed through contracting services, Stamer said Prospect Waterproofing is a leader when it comes to green initiatives in the roofing industry.

“Many factors are driving green,” Stamer said. “With the media and government focusing on global warming, we are looking for means and methods to improve the environment.”

With the increased number of opportunities to provide green roofs, the topic of discussion this year has focused on the maintenance of vegetative roofs.

Where Green Fits

Prospect Waterproofing performs its work mainly in the Chesapeake Bay Watershed, an area it is also helping to protect.

“Washington, D.C., has passed a law stating that private projects of more than 50,000 square feet be built to green specifications by 2012,” Stamer said. “Other local jurisdictions expedite the permit process. In order to reduce storm water runoff, green roofs are promoted and dollars can be saved in construction through the reduction or elimination of storm water management tanks.”

In many cases, said Stamer, private developers looking to lease space to the government must meet Leadership in Energy and Environmental Design (LEED) Green Building Rating System requirements.

“If green roofing covers over 50 percent of the roof area, one point can be achieved through LEED Credit 7.2, ‘Heat Island Effect Roof,’” Stamer noted. “Vegetated roofs can also contribute to storm water management points available under Credit 6.2.”

Owners and developers are also looking at green as amenity space, Stamer said. “If you are building a high-rise apartment that overlooks a three-story retail area in a mixed use project, will it be easier to rent or you can rent for more if the three story area is green as opposed to standard roof ballast, granular surfaced modified, white TPO.”

Green Roof Systems 

Stamer said Prospect Waterproofing Co. has found that the Protected Membrane Assembly is particularly suited for a green roofing application.

“As hot rubberized asphalt came from the waterproofing world, they are comfortable warranting their products in a green roofing application,” Stamer said. “Prospect Waterproofing has worked with American Hydrotech on many green roofing projects, especially on concrete structures.”

Stamer noted American Hydrotech was one of the first to introduce green roofing technology to the American marketplace in teaming with ZimCo, and it continues to offer a full product line for green roofing assemblies.

“Hydrotech has invested in the industry by placing on their staff both a soils engineer and landscape architect to assist the design community and provide tech support to approved contractors,” Stamer said. “Prospect has also installed Sarnafil green roofs, Henry, GreenGrid, and is approved to install Firestone, GAF, Live Roof, Carlisle and Barrett.”

Maintenance of Green Roofs

With the increased number of opportunities to provide green roofs, the topic of discussion this year has focused on the maintenance of vegetative roofs.

“Prospect has and continues to develop our crews’ capability for maintaining green roofing applications,” Stamer said. “More and more specifications are requiring maintenance be included for the first year or two as a condition of the contract.”

The norm, Stamer said, is to achieve 80 percent coverage within the first two years. “The key is to ensure that sedums are established within the first three months,” he said. “This may mean two to three trips a month for weeding and watering with a special emphasis on spring and fall.”

Still, Stamer said one to two trips per month for the remaining nine months to weed and water may be necessary, or approximately eight to 10 trips in the second year.

“We automatically schedule this work,” Stamer said. “Each crew reports on the progress of the roof and whether additional trips are necessary.”

Prospect Waterproofing made green roof maintenance a priority to ensure that building owners were satisfied.

“Prospect started maintaining our green roofs as it was clear that owners/developers expected that once complete they would be able to view and show off the fully grown completed roof to their clients, occupants and even competitors,” Stamer said. “We also noted that we had control over the maintenance by performing it internally. Owners spending additional funds for green roofing projects have high expectations. If no maintenance plan is called for weeds/spurge, it will begin to grow and choke off sedum promulgation.”

Staying observant of plant progress, early recognition of issues and expeditious correction of problems are keys to successfully establishing a roof garden.

Tips on Educating Building Owners

Stamer provided several keys to help educate building owners. “We have to manage an owner’s expectations,” he said. “In today’s current market with the use of sedums, owners cannot expect to see instant green. Over time with proper maintenance an owner can expect a lush vegetative roof that is visually appealing during peak bloom periods and dormant during extreme cold or hot months.

Stamer suggested that owners include one to two years of maintenance as part of the contract documents.

“Once the plants become established and dominant, minimal maintenance is required,” he said, noting that planting should be scheduled to ensure timely installation of sedums.

“Getting the plants in the growing medium quickly increases the likelihood of plant success and decreases the need for maintenance of the sedum tray,” Stamer said. “On sites where other trades may access the plant area, scheduling the installation to minimize construction traffic over completed areas will reduce plant damage.”

Stamer said inspections should begin soon after the plants are in place.

“Plant health problems, weed problems and wildlife issues are easier dealt with if recognized early,” he said.

“The frequency of the inspections is dependent on several factors; planting time relevant to the growing season, dormancy periods, likelihood of weed promulgation and weather - particularly drought conditions. Quick and appropriate action to correct problems early on will allow for optimum maturation of the plants. Staying observant to plant progress, early recognition of issues and expeditious correction of problems is the key to plant success.”

Planting the Seeds

James Stamer’s knowledge of the roofing industry did not start with Prospect Waterproofing in 1992; rather the process began when he worked with his father on a roofing crew during the summer months in the 1980s.

“My Dad was a foreman for a Baltimore company called William F. Zeller, which was purchased by Warren Ehret and Linck,” Stamer recalled. “I was then fortunate to work for two fantastic gentlemen at Prospect: John Van Wagoner and Robert Barlow in 1982.”

In retrospect, it was what he learned in the ’80s that helped paved the way for Prospect Roofing in the 1990s, and now the future looks bright.

How did James Stamer do it?

“By providing great service, exceeding expectations and surrounding myself with hardworking, smart individuals,” Stamer said. “We have built long-term relationships with our clients and our vendors and look to provide systems that perform.” CR