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Fact or Fiction: Green Roofs
by Staff
Are green roofs easy or hard to maintain? Do they cost a lot? How much energy do they save, anyway? Test your knowledge in this "cool" quiz.

On a hot summer day, the surface of a traditional roof can be as much as 90 degrees Fahrenheit hotter than the surrounding air.

  • Fact
  • Fiction

Green roofs, also called "rooftop gardens," can only be installed on perfectly flat rooftops.

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It costs more than twice as much to build a "cool" roof than to build a standard roof.

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An "intensive" rooftop garden, with deep soil and complex plantings, can absorb more than half of the rain that falls on its surface.

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The surface of a green roof can actually be cooler than the surrounding air temperature.

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A roof mist cooling system uses high-pressure hoses to spray a steady stream of water across a rooftop.

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Once installed, a green roof requires no maintenance.

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A ballasted roofing system uses rocks to keep the waterproof surface of the roof in place.

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A 10-inch tubular skylight can be installed in an afternoon and illuminate about 100 square feet of living space.

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A cool roof can remain 50 to 60 degrees Fahrenheit cooler than a standard roof on a sunny day.

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Since green roofs are such a new concept, little is known about their sustainability or longevity.

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There is only one type of roofing product that meets Energy Star qualifications for cool roofs.

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Metal is not an acceptable cool roofing material because it traps so much heat.

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White rooftops are generally the coolest and most reflective, but almost any color roof can be a cool roof.

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Rooftop gardens help to reduce greenhouse gas emissions.

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Generally speaking, a green roof costs more to install than a cool roof.

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Urban Heat Island is the name of a new reality show where contestants test their endurance by performing feats of strength on a hot rooftop.

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A green roof can help to reduce both cooling and heating bills.

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The rooftop garden on Chicago's City Hall covers 20,300 square feet (nearly an entire city block!) and features more than 20,000 plants.

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Over its lifetime, a green roof may actually be less expensive than a conventional roof.

  • Fact
  • Fiction