By Jason Wedmore
The “green” movement has taken over our way of thinking. From hybrid cars traveling the streets to reusable shopping bags being offered in grocery stores, we find green initiatives everywhere we go. With the big push from various organizations and government legislation, this is a trend that we will hear about for years to come. Many cities are encouraging the installation of green roofs, an aesthetically appealing, more energy efficient and environmentally friendly alternative to tar, gravel ballast, shingles or tiles. To the people who know how to make money by being green, it’s music to their ears.
Trending toward “green”
As with many trends, Europe was the first to embrace green roofs and see a rapid increase in popularity. Thanks to government legislative and financial support, the industry is now well established, yet still experiencing growth.
In the United States, industry leaders have begun doing more consumer education, a necessity in understanding the long-term benefits and looking beyond the initial cost.
In 2000, Chicago’s City Hall exchanged its tar roof for a green one. It began as a demonstration project for the city’s Urban Heat Island Initiative.
Through the initiative, scientists have helped monitor differences experienced through the change, and one major difference was confirmed early on. At 1:45 p.m. on Aug. 9, 2001, the ambient temperature was in the 90s. When rooftop temperatures were checked, scientists found there was at least a 50-degree difference between the new green roof and a tar roof. Based on this, the city anticipated saving $3,600 per year on energy costs through an estimated annual reduction of 9,272 kilowatt hours and 7,372 therms of natural gas.
After calculating the success of this project, the city now requires new buildings receiving city financing to have green roof. It also offers grants to retrofit green roofs on existing buildings. Seattle followed suit, requiring 30 percent plant coverage on commercial developments in certain zones. Even more recently, New York City passed legislation offering a significant tax credit to buildings adding green roofs. If a building owner covers at least 50 percent of the structure with greenery, there will be a full-year property tax credit up to $100,000.
Besides showing the support that’s spreading nationwide to install green roofs, these locations also illustrate that the market for green roofs isn’t just in warmer climates. Rather, the main U.S. growth has been focused around bigger cities that have been suffering from the Urban Heat Island Effect. Climates don’t dictate feasibility, only vegetation choice and possible irrigation options. For, the “Windy City” chose drought-resistant plants to counter moisture lost due to high winds.
Moving from arduous to efficient
With the U.S. being in the infancy of this growing trend, demand for green roof contractors, landscape architects and installers can be expected to grow as well. There are several players in the green rooftop business that anticipate job growth.
When considering the application, an engineer must first determine if a building’s structure can accommodate the weight of being retrofitted with a green roof. For new buildings, architects must work the concept into the plans. Contractors choose the material and vegetation based on the customer’s needs and location, and after installing the initial waterproofing and drainage layers, they prepare and apply growing media to the roof. Later, the contractor and landscapers may return to plant vegetation.
Of these jobs, great advancements have been made in the process of applying the growing media. The old method and the one still employed by a number of contractors involves using a crane to hoist material to the roof, where a crew of workers uses wheelbarrows to haul, dump and spread it, making it as even as possible to ready it for plantings. Some roof designs are complicated, and often impossible, with this method. Let’s say the project requires going up six stories, across the roof, and then down two stories into a courtyard. A crane just won’t cut it, which leaves installers to haul the material up through an elevator and spread it by hand. By this stage of the building’s construction, transporting green roof materials through a nearly finished interior is not typically a welcome task and can actually damage the building. Even without the risk, the time involved makes the job especially prohibitive.
But there’s another way that’s much faster, easier and takes fewer personnel than traditional methods. Furthermore, it spreads material more evenly and can even handle the above courtyard scenario without giving pause. Of course, this all means it costs less too.
In this method, pneumatic blower trucks park on the ground level and deliver materials to a building’s roof through a blower hose. A work crew simply drives the truck to the building, pulls the hose up to the rooftop and applies the material -- aggregates, mulches, compost or any variety of soil blends for rooftop gardens -- by blowing it smoothly and evenly across the needed location. Grid setups for pathways are no problem with the blower hose either. Depending on the truck specifications, the material and the project conditions, the product can be delivered straight up 150 feet or more.
As an added advantage, some pneumatic blowers are capable of Terraseeding, a patented process in which the truck injects seed and fertilizer into the growing medium, combining the steps of laying dirt and planting vegetation. This enhances germination because the seed is planted rather than exposed on the surface.
Portability also makes the trucks an ideal option for installing green roof growing media. Forget cranes, wheelbarrows, loaders and man lifts, as well as the hassles they cause by obstructing roads and pedestrian areas. Don’t worry about needing a contingent of workers either. Only two people are needed to operate and install the growing media with this method -- a mere fraction of the crew needed with the traditional method. When the job is done, the crew simply breaks down the hose and continues on its way. The end result produces a smooth, even application of material in less time and with considerably less effort than traditional methods.
Think of the cost savings. Renting a crane can cost up to $1,500 per hour. Plus, an installer is paying the hourly wages for a crane operator, another couple of people on the ground to load the material and then three or more on the roof to receive and spread the material. By the time the job is done, the soil mixture has been handled several times -- it’s mixed and brought to the site, moved from the truck to the crane and lifted to the roof by a second crew, and then spread across the roof by a third crew. It’s incredibly inefficient and costly.
In contrast, pneumatic blower truck operators reduce handling to a single crew. The soil mix, mulch, compost or aggregate is loaded into the truck, which parks at the site and delivers the mix directly to the roof, where it is applied evenly without the need to spread it by hand. The truck also could be loaded with material onsite.
Green roof installers have said it takes a crew of three about 15 minutes to install a single yard of material -- so four yards per hour. Using a pneumatic blower truck, that crew drops to two people who install at a rate of 15 yards per hour -- nearly four times the work done with two-thirds the crew size. Depending on the product composition and the height of the building, material can be applied at a rate up to 35 yards per hour, which is almost nine times faster than with the traditional method.
Taking the leap
All of these calculations can easily add up to thousands of dollars in cost-savings -- more with the greater size of the project. Installers across the U.S. can offer concrete examples of these savings, yet, as a green roof contractor, subcontracting a job can be a tough decision. It’s nice to keep everything in-house, so why pay somebody else when your crew is capable of performing the work?
Subcontracting the material application saves money and time -- making more for you in the end while helping you accomplish more jobs, thus making even more money. It frees your crew to perform less tedious work as well.
On the flip side, green roof contractors hesitant to subcontract might consider purchasing a pneumatic blower truck. Some are moving this route to continue to provide an all-in-one service to their customers, but to provide it in less time and for less expense. With any investment it’s important to do a cost analysis to calculate return on investment on purchasing versus subcontracting.
For those already in the pneumatic blower truck business, adding green roof growing media installation to one’s repertoire of services is just a natural extension of what’s already being done. Blower trucks easily create green on the ground by spreading mulches, soil blends, aggregates and more for parks, green spaces and residential lawns. The increasingly popular green roof trend is just one more avenue to incorporate a truck’s services.
With a focus on the environment and conservation, along with greater knowledge of the long-term financial benefits, it’s no doubt that green roof contractors, installers and architects will see greater demand in coming years. And that pace will only increase as more cities require green roof space. Fortunately, material installation methods are advancing alongside the green revolution, making a positive impact not only to the environment, but especially to an operator’s bottom line.
Jason Wedmore is national accounts manager for Express Blower, Inc.