Green Roof Construction

From hybrid vehicles to natural cleaning products, environmentally conscious alternatives have made their way into almost every industry. But according to James Kirby, director of technical communications with the National Roofing Contractors Association, sustainable alternatives, while in the works by many manufacturers, had limited use in the roofing industry—but the market is growing.

While the actual materials roofing contractors use may not yet be sustainable per se, the types of materials a contractor uses and the way they design and even deconstruct a roofing system can ultimately affect how the project’s life cycle impacts the environment.

A greener design
“For the vast majority of buildings in the country, what you do on the roof will affect it tremendously,” says Kirby. For that reason, when roofing contractors pay special attention to certain design details, they can transform a standard roof to one that creates a more energy-efficient building.

For instance, by simply choosing light-colored or white reflective roofing materials, roofing contractors are building a “cool roof”—an ENERGY STAR approved roof that reflects more of the sun’s heat than it absorbs. This creates a more energy-efficient building as a result, in addition to preventing wear and tear on the roof and saving the occupants money, says Gene McCormick of San Diego-based Gene McCormick Construction.

And according to the Cool Roof Rating Council (CCRC) additional benefits of cool roofs extend beyond the building and its owner. Cool roofs mitigate global warming, smog and the urban heat island effect—heat generated from areas with a high population density usually resulting in increased energy cost during the summer.

Designing with rooftop gardens in mind is another way to achieve sustainable roof systems. “Putting vegetable gardens on the roof absorb the heat and help cool the ‘concrete jungle,’” adds McCormick.

Kirby also recommends roofing contractors incorporate walkways into the roofs’ design for use by maintenance professionals. This way any treading on the roof is restricted to one area, preventing damage to the roof and helping to lengthen its lifespan.

Choose the right product
While eco-friendly branded roofing materials are still in the works, roofing contractors can build roofing systems from products that are sustainable—resulting in fewer resources used in the long run—or materials that are renewable or recyclable.  

McCormick recommends using concrete or clay tiles so when damaged tiles need to be replaced they can be ground up to make new tiles. McCormick also favors shingles with a 50-year lifespan versus more common and less expensive shingles with a 20-year life span.

“It’s easier for the client because they only have to pay for a roof once, and you only have to throw away a roof every 50 years instead of every 20,” he says.

McCormick also strongly recommends the use of fire resistant underlayments, especially in arid regions where fire storms are more common. He says using a granulated underlayment that is fire-rated can save the structure of a building during a fire, and ultimately ensure a long roof life.

Finish the job right
When constructing a roof, certain elements need to be in place to ensure a long, durable life span. Kirby insists contractors install two layers of insulation as well as stagger the joints to prevent air movement and reduce thermal value. Kirby also encourages contractors to use extra thick membranes to increase a roof’s durability.

At a job’s end, the easiest way to ensure a green project is to have responsible dumping practices. After a roof deconstruction, McCormick encourages contractors to separate the wood from the asphalt. Most of the asphalt can be recycled and used for road pavement, while the wood can be turned into mulch.

Offer incentives
One of the key parts of a durable and sustainable roof life is good solid maintenance, says Kirby. Roofing contractors should instruct their clients to check the roof for debris and clean it off periodically. Kirby recommends contractors offer check-ups twice a year, and even set maintenance service plans.

“If a little bit of money every single year can make a roof last years longer, it is money well spent,” he says.

And to encourage more environmentally sound roofing projects, Kirby says roofing contractors should inform building owners of any tax incentives put in place by local or federal governments.

In the end, when it comes to greener roof construction, all it takes is a little extra planning and wiser product selection.

“It’s how the system is installed and the characteristics of particular roofing materials that make a roofing system sustainable or not,” says Kirby.