Pointers Before Installing a Green Roof

Sourced from The Villager

It’s hard to miss the soaring 3-acre meadow that graces the top of Barclays Center in Downtown Brooklyn. But green roofs — or living roofs, as they are also known — are also branching into residential neighborhoods, where homeowners with sturdy-enough roofs can enjoy their environmental and financial benefits.

“Not only are green roofs really beautiful, nice places to hang out and good for the environment, but they save the building on energy costs and make it a lot cooler,” said Inger Yancey of Brooklyn Green Roof. “The top floor will be 5 to 7 degrees cooler than outside, if it has a green roof. It also cuts down on sound, and in winter it keeps more of the heat inside.”

Green roofs can also extend the life of a roof by 50 years or more by adding a layer of protection from the sun and other elements.

If you’re considering a green roof on your brownstone rooftop, here’s what you need to know:

“The place to start is with the structural integrity of the roof,” said Eric Dalski of Highview Creations.

A structural engineer can provide an assessment by reviewing architectural drawings or drilling into the ceiling to see the joists.

“What is a problem is when the weight is too much and you can have cracking,” Dalski said. “I recommend a leak-detection test or new roof that is certified by a roofer, so it’s good to go.”

Though steel joists are preferable to support the weight of a green roof, most brownstones and row houses have wood ceiling beams.

“But the narrow span means wood is usually not a problem,” said Gwen Schantz of Brooklyn Grange. “Most brownstones you can generally put a shallow green roof with 4 to 5 inches of soil. Or you can put in a smaller green roof, too, and just cover part of the roof.”

The design of the green roof will depend on the strength of the roof: A stronger roof will allow for deeper soil and more diverse plantings, such as wildflowers and vegetables.

Read the full article