Green roofing is relatively new to the U.S. although the concept is older than the Hanging Gardens of Babylon, and hadn’t been perfected until Advanced Green Architecture (AGA) rose from the graduate research of Erik Cronk and Jeremiah Johnson.
While attending an American Society of Landscape Architects (ASLA) conference in San Francisco in 2007, a seed was planted in Cronk and Johnson’s brains during a green roofing seminar. While their contemporaries at Michigan State University’s Landscape Architecture program concentrated on finding jobs, Cronk and Johnson decided to forego the workforce for advanced degrees.
“Right after we graduated with our undergraduate degrees we had an idea that green roofs would be a product we’d like to develop. We were undergrad colleagues that became friends and we were the only two kids in our class that wanted to pursue [an advanced] degree at that time,” states Johnson.
As the only graduate students in MSU’s Landscape Architecture program, the pair focused their research on sloped roofs and storm water management, cognizant both factors were absent from existing studies; most were based upon German practices stemming from the 1960s.
“We looked into sloped science, temperature and moisture correlations… temperatures can vary dramatically in summer due to solar insolence. This leads to problems with south-facing slopes that wouldn’t thrive due to dramatic temperature and moisture variations. Our research demonstrated that if you want a sloped green roof system to thrive, you need irrigation, and you will want subsurface irrigation,” says Cronk.
The Advanced Green Roof (AGR) is a modular system of plastic trays made from 100 percent recycled high-density polyethylene with built-in irrigation channels. Biodegradable walls made from 100 percent recycled pulp sit upon a drainage layer with built-in irrigation channels. Filled with soil and re-grown with the proper mixture of plants, the modular widgets are inlaid with a capillary mat, which acts as a sponge, soaking the roots. Waterproof membranes and a protective mat lay beneath the widgets. The modularity allows for easy access beneath the roof. Although the initial cost may seem expensive, the AGR may theoretically last for the life of the structure.
“With a mix of science, function and design, we developed a product that functions properly and grants designers the ability to integrate both form and function into their green roof designs,” Johnson says. “We saw a need and looked at the best way to meet that need. Designers should have came out with this prior to us.”
Yet, the AGR lacked a solid entry into the marketplace. Enter Jim Bush of Weather Shield Roofing Systems, a repeated member of the “Top 100 Contractors in the USA” according to Roofing, Siding, and Insulation Magazine. Bush met Johnson through a mutual friend, quickly acting as an advisor. A 32-year veteran of the roofing industry, his insight was just what AGA needed. Bush became a partner in early 2012.
“A green roof is first and foremost, a roof,” Bush explains. “It has to keep the water out, it has to do its job of protecting the building. What I realized is that the people in this [business] are either growers selling plants or manufacturers that sell plastic trays. In both cases, they know virtually nothing about roof design or landscaping… each [of us] has a unique area of expertise that wasn’t readily available in the marketplace. There are a lot of people that can grow plants -- that isn’t where the magic is. It’s how these come together to make a reliable, waterproof roof that is also aesthetically pleasing.”
Benefits include another layer of insulation lessening heat loss in winter and gain in summer, storm water runoff reduction, and less carbon dioxide output. Economic benefits include thermal insulation reducing heating and cooling costs. Cities also increase these benefits; Milwaukee, Philadelphia and Toronto are leaders in this area. Other cities, like Ann Arbor, tax impervious surfaces or storm water runoff, which the AGR helps reduce.
“When we completely protect a roof so UV doesn’t touch it, thaw is minimized, there is no roof traffic -- people aren’t dropping tools on it, hail never hits it, ice and snow aren’t abrading it. You eliminate all of that, you’ve buried it. I personally believe 100 years is an easy estimate as to how long the underlying roof waterproofing should last,” claims Bush.
A local representation is the idyllic Christian Reformed Church of North America at 2850 Kalamazoo Ave. SE. Others can be found in Grand Rapids, Caledonia and Traverse City; California, Alabama and Chicago, Ill. with distribution as distant as South Africa.
For more in-depth information on Advanced Green Architecture’s patent-pending creations, including an extended listing of benefits, visit agrgreen.com
Matt Simpson Siegel is a Michigan-based writer whose most recent work includes the soon to be released Michael Maltese-inspired sock puppet short film, “Close Encounters of the Fanged Kind.” He would also like you to invite him to your rooftop golf course once it’s completed.
Photography by Adam Bird