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Irrigation on Extensive Green Roofs

Green Team at Green Roof Technology, - Thursday, May 02, 2013

By: Jörg Breuning

The main purpose of an extensive green roof is stormwater retention and delaying stormwater runoff amongst many other added values.
 
Above: An Irrigated Green Roof 

In the last decade, I've seen many green roofs where the intended plants never really flourished. I estimate that in the US at least 50% of the green roofs are not performing to their fullest potential. This can be observed by simply looking at the most obvious of indicators, the plants themselves, regardless if they were planted on purpose or somehow found the space to take root.  Most of these less healthy extensive green roofs are pre-planted boxes, or commonly known as modular systems. Not only are these systems much more costly, the mid to long term results are often far below systems that are assembled in place and at the time of installation.

I know that the transition from being a common nursery-grown plant (including pre-planted boxes) to the extreme environment of a rooftop poses severe challenges. Green roof plant nurseries typically have "great" advice and recommend the installation of temporary or more permanent irrigation systems. This advice is defeating the purpose of an extensive green roof and shows that asking self-appointed experts can cause a spiral of failures. Since many green roof installers lack the proper horticultural knowledge, they may not be able to identify problems by simply looking at the indicators (the plants). This could cause the problem to gain momentum. In addition, the false conclusion that technology (Google search, Apps, synthetic growth media or sophisticated soil moisture control devices) can fix the problem supports my theory of less experienced or misinformed green roof professionals. They rely heavily on technology to fix any issue and miss the big picture. Nature has the ability to take care of itself, as long as the appropriate design, materials and plants are used in addition to being familiar with the immediate climate.

Green roof designers and green roof professionals must understand that less is often more when it comes to extensive green roofs. No building owner wants to irrigate their roof in short, mid or long terms. There is no need to make a green roof more complicated by using multiple synthetic or plastic layers. LEED™ certification supports using gray (recycled) water for green roof irrigation; but what is the point of watering an extensive system when it's main purpose is to retain stormwater? Common sense and experience are the only two things that will aid in planning the perfect green roof.


Above: An Unirrigated Green Roof

Implementing irrigation on an extensive green roof is a clear sign of not understanding the basic principles of horticultural techniques or the laws of nature. Irrigation reduces the water retention, increases the nutrient pollution in runoff and requires higher fertilization application. Irrigated extensive green roofs are not environmentally friendly, not economically feasible and have hardly any payback for the building owner.

I tell my clients if they have an offer or design for an extensive green roof that includes irrigation - be cautious!

 

Green Roof Technology Partners with Anacostia Watershed Society

Green Team at Green Roof Technology, - Friday, April 19, 2013

By: Samantha Yurek


Photo Credit: Anacostia Watershed Society

Green Roof Technology has recently partnered with the Anacostia Watershed Society; an organization dedicated to keeping the Anacostia River clean and healthy. Through our partnership we hope to achieve a common goal to increase green spaces and to protect our Anacostia River watershed which runs through our nation's capital and into Maryland. Since 1989, the Anacostia Watershed Society has been the first organization dedicated to protecting the Anacostia River.

ThAnacostia Watershed Society had recently put forth a Green Roof Rebate Program, aimed to encourage residents and building owners to reduce their stormwater runoff on-site and decrease the burden on the District's Combined Sewer Overflow. Available for residential, commercial and institutional properties, this rebate program will reimburse you with $5 per square foot of green space implemented on the property.For most commercial green roofs, that rebate can reduce your overall costs dramatically.

The District Government's Green Roof Rebate Program is administered by the Anacostia Watershed Society and encourages to contact us to see if they are eligible. Feel free to check out the Anacostia Watershed Society homepage here.


Photo Credit: Anacostia Watershed Society

Stormwater Fee Looming Overhead

Green Team at Green Roof Technology, - Thursday, April 11, 2013

 By: Samantha Yurek


Photo Credit: The United States Geological Survey

The Chesapeake Bay is the heart of Maryland. Not only does it fuel our economy and recreational activities, with over 64,000 square miles it is home to over 2,700 different species of flora and fauna. It is an important resource that should be cared for adequately.

Excessive runoff is a huge culprit of transporting trash, chemicals, nutrients, along with other things that end up polluting the bay. With storm season lurking around the corner, Maryland is trying to prevent these mini flood events from polluting the Bay even more.  To mitigate for these rushing stormwater events, stormwater fees  will soon be added to everyone's quarterly water bill. There is no avoiding this fee that will essentially be paying for the impervious surface area one has on their property. Residential properties won't have such a heavy fine, but businesses may have to start paying a pretty penny. For example, take a look at any mall, the entire property is a combination of roof and blacktop.

The stormwater fee may be something you worry about, but there are ways to reduce the fees.  Planting trees, implementing rain gardens, and most importantly, adding vegetation to your rooftop are all proven ways to earn credits toward reducing the cost of the fees. Let's strive to keep Maryland beautiful; the Chesapeake Bay thanks you.


Photo Credit: Green Roof Technology

First International Bird Airport on Intensive Green Roof

Green Team at Green Roof Technology, - Monday, February 18, 2013

 Ornithoport in Bonn

Picture: Bundeskunsthalle

Airports are plentiful in our world, but a unique concept involves creating airports specifically for birds.  An exhibition on the roof of the Art and Exhibition Hall over the summer of 2012, highlights this common area as a destination point for birds.  To aid this bird airport (ornithoport), nesting boxes and feeders were installed, as well as approach and departure structures, complete with flashing airport signals and safety announcements.  All together this presentation is not only an awesome art piece, but probably the best landing facility for birds from all around the world.  The curator of this project, Professor Res Ingold explains, "In our case, it is an artistic project with scientific backing."

Founded in 1992, the Art and Exhibition Hall of the Federal Republic of Germany has played an important role in the community of Bonn, Germany.  Designed by the architect, Gustar Peichl, the building displays various exhibitions in fields of art, archeology, cultural history, science, and technology.  Aside from exhibitions, the community center frequently hosts symposiums, conferences, performances and concerts.  One of the more attractive aspects of the building is the intensive rooftop garden, which is often site for sculpture displays.  This vegetated rooftop is a nice addition for relaxing with a fantastic view of the surrounding city.  In the summer refreshments are served at the beer garden, wildflowers brighten the landscape and the air is busy with buzzing honeybees.  Multiple honey bee colonies call this rooftop garden home.  In 2012 these little magnificent creatures produced 1,200 pounds of honey!  Accurate daily monitoring of the productivity of the honey bees is accessible online in German, French and English. 

Green Roof on Floating Home "Siberfisch"

Green Team at Green Roof Technology, - Monday, January 21, 2013

First Sustainable Home on the Water with a Green Roof

 

With the cost of living in large cities constantly rising, the search for viable alternatives is constant.

Flo Florian and Sascha Akkermann of design firm Confused-Direction and the project-developer Bernhard Urich had urban affordability in mind when they designed the Silberfisch houseboat.

The house is a thoroughly modern floating home that, instead of occupying a valuable plot of land, is anchored in a body of water. In theory, the Silberfisch would allow residents to remain in a location indefinitely or relocate on a whim. It’s an interesting concept whose acceptance by the general public might be debatable.

However, the eco-friendly principles underlying the house are universally appealing. Two of the primary “green” methods used in the house’s construction are a green roof planted with vegetation and the use of reclaimed wood wherever possible. The toilet is an Eco-Toilet which saves water recources. Additionally, the house produces zero emissions. As home prices and eco-friendliness become increasingly critical issues, Confused-Direction’s Silberfisch houseboat may become a realistic option.

 

 

 

 

 

 

 

 

 

Silberfisch houseboat is a floating home by Bernhard Urich and the guys from the design firm Confused-Direction Flo Florian and Sascha Akkermann. This eco-friendly project, with zero emissions, represents a balanced mix of design and maritime romance. It has been designed for the areas with big water surfaces or in cities where property costs are high house boats offer an alternative.

Visit also their home page:  www.schwimmhausboot.de/

 

Sun-Root System unfazed by Superstorm Sandy

Green Team at Green Roof Technology, - Tuesday, December 04, 2012

by Ryan Miller

In April of 2012, Green Roof Technology introduced the first Sun-Root solar green roof system to the United States when we installed a 1 kW system (4 Sun-Root Modules) atop the New York Parks & Rec. office on Randall’s Island in New York City. The rooftop, which is eye-level with commuters on the Triboro bridge, creates and stores enough power during the day to power a series of rooftop LED lights throughout the night.  New York City Parks & Rec was drawn to this technology as a means of adding solar power without the need to drill into the membrane to harness the solar array.

Although controlled wind studies have already proven the strength of this system, we are now able to report some real-life wind tests.  Recent Superstorm Sandy made landfall late October, only 6 months after installation, and left without moving the Sun-Root System an inch.  New York City reported maximum sustained winds at 85 mph with some gusts reaching 92 mph .  Upon visiting the site a week after the storm made landfall we found that our original placements of the Sun-Root withstood the winds without a shift.   Jorg could not be happier.


Revolutionary Philadelphia Green Roof

Green Team at Green Roof Technology, - Thursday, June 21, 2012

By Kat Harrold

 

Image by Realen Properties

Philadelphia has one of the most progressive green roof programs in the country.  Their support for green roofs in based on an aggressive stormwater management plan to hold all run off on site.  Beginning late this fall, The Philadelphia Convention Center Parking Facility will open utilizing an architectural marvel featuring a combined blue roof and green roof system designed by Green Roof Technology and Realen Properties.

Green roofs and blue roofs are both great for capturing stormwater onsite.  Green roofs retain water by acting like a giant sponge while blue roofs hold the water on the roof similar to a rooftop swimming pool.  Blue roofs may hold more water than green roofs during intense storm events, however the standing water can create stress on the building and breed mosquitoes and bacteria.  The revolutionary green roof on The Convention Center Parking Facility combines only the best of both these technologies.  The green roof has an extra deep profile affording higher water storage capacity.  In addition to the added growing media, a specially designed insert for the roof drains holds water up to a couple of inches within the lower layers of the growing media.  When a 100 year storm event occurs this insert has an overflow mechanism allowing the roof to drain freely once the max saturation level has been reached.      

Beauty and intelligence are key to the success of this project.  Not only is the function of the green roof innovative and practical, the aesthetic will be just as exquisite.  The green roof will be visible from the Philadelphia Convention Center and accordingly will feature an eye catching seasonal display of color through a mixture of native ever greens, grasses, and perennials.  Crocus, and daffodils burst with color in the spring providing seasonal interest.  In the fall and winter months scarlet mahonia and evergreen ferns add to the festive decor.



Good News for EPDM Roofs!

Green Team at Green Roof Technology, - Thursday, May 03, 2012

By Kat Harrold

Photo courtesy of rv-roof-top.com

Good News!  EPDM (ethylene propylene diene monomer) is a synthetic rubber waterproofing commonly used on roofs.  Once thought to be incompatible with (electric field vector mapping system), due to too much black carbon interference, now has compatible grey and white versions!  

What does this mean?  It means that if you want to use EPDM waterproofing under your green roof you can also have the piece of mind by having one of the most accurate leak detection systems installed as well!  In many cases the leak detection system is cheaper than the waterproofing warranty as well.




Run-Off Quality - Extensive Green Roofs

Green Team at Green Roof Technology, - Saturday, October 22, 2011

Green roofs are vegetated soil filter where the naturally loosened root zone creates an enhanced degradation and retention of pollutants. The older the green roof the better the performance - considering the green roof was designed, constructed and maintained according the worldwide accepted FLL Guideline. Based on higher temperatures in summer the release of nutrients can be higher but will be still far below the strictest German drinking water ordinance as different studies showed in long term studies between 1999 and 2003 in Germany (W. Kolb, G. Mann, M. Köhler). However most run-off is more or less stained by humic substances that are typically caused by organic matter including releasing substances of the plants.

Since this is just a visual issue (no overall quality problem) the run-off water can be easily stored in cisterns. The water can be used for toilet flushing, irrigation, car washing and other purposes. Colored water is not recommended for doing the laundry, it might stain white fabrics. Research from Köhler (1993) and Liesecke & Borgwardt (1995) also showed that green roof have the ability to filter airborne pollutants efficiently, like lead, copper, zinc and formaldehyde.

To minimize run-off water coloration the initial organic content of the growing media can be reduced. Ideal are green roof layers with high mineral content (drainage and green roof soil). Within the FLL guideline Green Roof Technology is able to enhance the removal of pollutants and run-off coloration at the same time. Specially engineered green roof growing media will perfectly customize for our clients need and based on leading research performed in Germany over the last 15 years. 

Since extensive monolithic green roofs retain as an average 50-75% the storage of the run-off (cistern size) has to be adjusted accordingly and is typical larger than without green roof.

Data from any Run-Off Quality research done in the United States or Canada can be just used as a rough speculation. We don't know any research performed with standardized components (e.g. growing media) and further more there is no uniform standard for compost or organic ingredients going into the growing media. Without uniform and standardize research all results are only speculation. Independent research (not sponsored by manufacturers) in Germany did consider these important facts and therefore the results are useful and easy to implement on real projects.

Any kind of plastics (drainage boards, chemical substances or modular systems) doesn’t support the cleaning power as much as perfectly engineered wall-to-wall green roof systems. More and more experts starting researching on how much chemicals are released by plastic components and water proofing materials since it well know that plastic components affect sea life  - where all run-off ends up.

On request Green Roof Technology will translate any information about leading green roof research done in Germany over the last 25 years. 


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