Go Go Green Roofs Jul16

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Go Go Green Roofs

Chicago’s Millennium Park is one.
Detroit’s Ford Rouge Factory is another.
So is Nintendo’s American HQ in Redmond, Washington.

We’re talking about green roofs, a remarkable way to help conserve energy, lower roof temperatures, clean the air, reduce noise inside the building, create mini-habitats for wildlife, manage stormwater, and extend the life of the roof itself.

A green roof in Singapore - the Sky Garden House by Guz Architects.A green roof in Singapore – the Sky Garden House by Guz Architects

Green roofs are definitely worth the effort. But you can’t just chuck a few bags of dirt and grass seed on a roof and call it a day. This endeavor calls for quite a bit of planning, and consideration of local weather and environmental conditions.

The window of opportunity to “plant” a green roof is a more narrow one in Northern climates than in, say, California or Singapore. But it’s still a possibility in a wide range of places.

“In terms of the technical aspect, there’s a bit of a fallacy about not being able to have a green roof in colder climates,” explains Steven Peck, Founder and President of Toronto, Ontario’s GRHC (Green Roofs for Healthy Cities) organization.

“I don’t think anything about the north poses any significant challenge to having a green roof. Yukon, Alaska is quite far north, and there are green roofs there. There are some great environmental things happening everywhere.”

Peck points out that there’s vegetation growing everywhere in the world.

“You just have to choose plants that can survive frost/freeze cycles,” he says, “we collect info on green roofs from Hawaii to Alaska.”

Sod or moss roofs are perhaps a couple of the simplest forms of green roofs, while others are called “intensive” or “extensive,” depending on the depth of soil needed, the complexity of the plants, and the amount of maintenance required.

“Intensive” green roofs often resemble parks, and can include things as tiny as cooking herbs and as large as small trees, while “extensive” green roofs aren’t generally walked upon, and only require minimal maintenance and fertilizing.

So where do you start?

Well, as mentioned above, a green roof may appear to be merely a layer of soil with greenery planted in it – simple on the surface. But an actual healthy, safe, useable green roof takes specialized planning, structural considerations, and of course careful plant selection, as well. There are a number of resources online that offer kits, explanations, and how-tos, but Peck suggests that, in the long run, it might be something best done with professional help.

“Green roofs really aren’t a DIY technology,” he points out. “You have to have professionals working on green roof projects. There are a lot of structural things that need to be taken care of, or you can cause serious damage to your home or building.”

The basics are – well, basic. You start with a waterproof membrane (most green roofs’ failures are said to involve water damage) and add a root barrier, such as concrete.

Next, you add a drainage layer like gravel to carry excess water to gutters and off of your roof. A filter fabric will help to hold your next step – your growing medium (soil mixtures) – in place. And an irrigation system will keep your plants healthy without wasting water.

Then, it’s all about the plants.

The possibilities are many when deciding what plants to include on your green roof. Depending on the size of the roof and the foundation, you may even be able to include small trees, a light gazebo, or benches as part of your venture.

Common plants included in green roofs, in addition to mosses and grasses, can be herbs such as chives, oregano, or thyme; flowers such as black-eyed Susans, phlox, dwarf balloon flowers, bellflowers, or asters; and other plants such as sedge, oatgrass, or the many varieties of stonecrop. Your green roof might even be able to support multicolored flowers, making it even more of a standout.

And if it snows? Then what?

“Snow is not an issue for green roofs at all,” Peck reassures, “that’s just something you take into consideration when you’re calculating the roof’s structural loading capacity – snow is already part of that consideration.”

Peck says that in 2010, the green roofs industry grew by 28.5 percent, a great indication that people are becoming more and more interested in integrating green roofs into their homes and businesses.

“One of the reasons green roofs are growing so rapidly is that there are a number of public and private benefits available for them,” he explains, “there are incentives and regulations to support the building of them, which is helping the whole green roof industry.”

Get more info on green roofs via Peck’s company’s website, www.greenroofs.org.