Creating a garden on your roof that saves energy, minimizes stormwater runoff, helps cool the city and offers a bit of green calm must be complicated.
Paul Weaver has good news for you.
“It’s a very simple process,” says Weaver, construction branch manager at Level Green Landscaping. “We can install a green roof for just about anybody.”
Level Green was recently certified as an installer by LiveRoof, a leading manufacturer of green roof systems.
That means Level Green crews were trained by a specialist at LiveRoof, learning how to install the product according to the manufacturer's instructions.
There are only a few such certified installers in the Washington D.C. metro area.
Why install a green roof? How to install a green roof? Will a green roof work for you?
Weaver has all the answers.
Why Install A Green Roof?
Lots of reasons:
Noise Reduction
Plants, soil, and air trapped in the soil are great acoustic insulators. Tests show that green roofs can reduce indoor sound by as much as 40 decibels — a great perk for city dwellers bombarded by noise from airports, industry, trains and traffic.
Tax Credits
Building owners can take advantage of tax credits for installing green roofs, Weaver says.
Cost Savings
“It cuts down on your utility bills by providing more insulation, so you’re not losing heat through the roof,” he says.
Reduction Of Stormwater Runoff
The soil in green roof systems acts like a sponge and absorbs excess rain water, and the plants naturally filter pollution out before returning it to the groundwater system.
Winged Creatures Love Them
Rooftop plants create helpful habitat for butterflies, insects and songbirds.
They’re cool. Literally.
“In cities like DC, it’s a great option,” Weaver says. “It’s always 10 degrees hotter in the city. There’s no plant material around to help cool things down.”
He’s talking about ”urban heat island effect,” the temperature difference between urban areas and their rural surroundings. Green roof plants help by cooling the air, slowing air movement and filtering pollution.
They’re Pretty
Who wouldn’t rather look out onto an oasis of green plants than a sea of hot shingles or asphalt?
Preparing For Green Roof Installation
Step One: Waterproof the Roof
First, roofers come in to waterproof the roof, if it isn’t already suitable. They do a flood test, Weaver says, flooding the roof and letting the water stand for a few days to see if there are any leaks.
And they check to see if the roof can bear the extra weight of a rooftop garden.
“Weight can be an issue,” he says. But green roof systems are available with lighter soil if needed.
Step Two: Installation
“First, we lay down a slip sheet,” Weaver says. “Then, we bring the trays of plants up to the roof.”
The plants come in pre-planted modules containing everything they need, from soil, drainage layer and fertilizer. Modules are available in 2-1/2”, 4-1/4”, 6” and 8” soil depths, to support a broad range of plants and roof loading conditions.
They’re designed to connect together. Crews of six work together to connect them, Weaver says, with each person handling a specific task.
“Once we get all the plants on the roof, either by using a crane or by our guys carrying them up stairs — and we get them all in place, we always say, ‘Wow,’” Weaver says. “It’s suddenly beautiful and green. We always take pictures.”
Step Three: Maintenance
Because rooftop plants are sturdy by design, they need very little maintenance, Weaver says.
Plants should be checked once a month for watering, weeding and fertilizing, he says, and crews can replace any plants that have died.
Irrigation systems are made specifically for green roofs, if you choose that option. Or arrange for maintenance visits once or twice a month.
“That’s all they really need,” he says. “They’re not like your garden out front.”
How Much Does A Green Roof Cost?
“It’s roughly the same cost as any other roof,” Weaver says.
The average green roof costs about $14 per square foot, he says.
“If you’re putting a shingle roof on, you might as well do this.”
Green roofs are often cheaper for building owners in the long run — the roofs don’t need replacing as often as traditional roofs. Plus, they save on utility costs by helping buildings stay warmer in winter and cooler in summer.
Will A Green Roof Work For You?
Probably.
“You can put one on any roof, flat or not,” Weaver says, although most of the roofs they install are flat.
“It’s easier to do on new construction, but we can do them on existing construction, too,” he says.
Weaver has installed green roofs on public schools, apartment buildings, hotels and office buildings.
“We’re installing one at an apartment complex later this year that will include a patch of green roof on the deck of each apartment,” he says. “It’ll be like having your own bit of lawn.”
It’s a great way to attract tenants, he adds.
What Kind Of Plants Can You Grow On A Green Roof?
There are lots of options, Weaver says, but the most common green roof plant is sedum, a drought-resistant ground cover with water-absorbing leaves.
“They’re indestructible,” he says, ”even on a 100- degree roof. They take the sun well and they don’t need much water.”
But customers can order the pre-planted trays with whatever they like, Weaver says. Native plants are common, as they require little care. Some customers want flowering perennials or hardy herbs.
“They’re not designer plants,” Weaver says. “They do need to be sturdy.”
Once you place your plant order, it takes six to eight weeks to grow the plants.
How To Install A Green Roof? Call Level Green
If you’re pondering installing a green roof on your building, join the club.
“This year we’ll triple the number we’ve done in the past,” Weaver says. All the obvious benefits, plus new tax credits means green roofs are more popular than ever.
“If you want one, too, give us a call,” Weaver says.
If you’re not already a Level Green Landscaping client, we’d love to add you to our growing list of happy customers.
Our focus is on commercial properties like offices, mixed-use sites, HOAs, municipalities and institutions in Maryland, Washington DC and parts of Virginia.
Contact us at 202-544-0968. You can also request a free consultation online to meet with us one-on-one.
We’d love to hear from you.
Image Source: LiveRoof Global, LLC
