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Water-to-Air Ratio GreenRoofs101

Green Team at Green Roof Technology, - Tuesday, March 17, 2020

Why is AIR-to-WATER Ratio on Green Roofs so important?

The air-to-water ratio is the ratio between air and water in the pores of a media. (Download PDF: click here)

 

By Green Roof Expert Extraordinaire Jorg Breuning, March 2020

 

Introduction (Challenges)

On ground disconnected structures like roofs the available rooting space for plants is typically limited because of weight restraints. Additionally the Green Roof components and the plants are exposed to more extreme environmental impact like higher wind speeds, reflecting surfaces, higher temperatures, air pollution, artificial light at night, lower bio-diversity and more. Water to Air RatioIn such locations the Air-to-Water ratio within the Green Roof system can fluctuate much more often beyond the desired range what causes stress on the plants and stress on beneficial microbes. 

If more extremes are expected, selecting the right plants and right Green Roof system is crucial. In some cases an irrigation system (temporary or permanent) or enhanced drainage system should be considered to reduce stress conditions on the plants and to improve soil biology. However, operating an inappropriate irrigation system (like sprinklers) or drainage systems that were never engineered specifically for Green Roof applications can be counterproductive because the Air-to-Water ratio is not considered. Constant adverse Air-to-Water ratio is the problem on over 60% of the Green Roofs in North America and with changing weather patterns this problem is getting worse.

 

What is AIR-to-WATER RATIO (Introduction)

The vast majority of plants used on extensive or intensive Green Roofs thrive best within a specific Air-to-Water ratio range in the root zone of a Green Roof system. Over the course of a year and depending on weather conditions, a Green Roof system’s desirable the Air-to-Water ratio shall vary between 35/65 to 65/35 (65% water/35% air to vice versa). An Air-to-Water ratio in such a range is important for the resilience of plants, for nutrient exchange capacity, pH buffering capability, and beneficial (aerobe) microbes. Peaks in one or the other direction (adverse Air-to-Water ratio) can be tolerated by the plants if this is temporary and very limited in time.

To successfully reduce adverse Air-to-Water ratio it takes, extensive experience, profound horticultural knowledge, understanding the historic developments, seeing environmental/natural facts, and the ability to evaluate natural indicators on existing Green Roofs. 

 

Understanding Green Roof Systems 

As long as humans have cultivated plants they have learned that natural parameters in biology, physics and chemistry are given and everything has to collaborate within these nature’s laws. Although we are able to Gen-manipulate plants for better yield, more pest resistant, and for more stress resistance, but the nature’s laws won’t change.

An increasingly number of stormwater professionals recognize that Green Roofs are an excellent, the least expensive and most natural stormwater management tool with many added values for the environment we live in.  However, as often we talk about Green Roofs as often these specialized professionals forget about the Quarterbacks or key players of such systems: the plants!

It is a simple fact that the more we do for healthy plants with a natural diversity, the better a Green Roof system can retain and detain stormwater.   

Within the development of modern Green Roof technology over the last 50 years most Green Roof systems are built with different continues layers.

The basic layers are (from roofing up): Green Roof System -typical

 

  1. Protection layer to separate between roofing and green roofing trade and to protect the underlying components.
  2. Soil/Media extension layer (often described as drainage layer) to mimic natural soil profiles and avoid anaerobe conditions in rooting zone.
  3. Filter layer that avoids fine particle migration within the system.
  4. Engineered Growth Media or soil that meets parameters of FLL*.
  5. Vegetation.  

 

INFO! Trays, pre-planted containers or modular systems try to mimic the same layers within a small defined area like a plastic box, metal container or soil filled bags. These systems are solely made for easy shipping which is blink of eye in the life span of a Green Roof. These systems are not continuously installed and so these systems are considered as a temporary solution for a limited time (5-8 years).  In most cases these planters or trays are getting re-planted or removed over time, many already ended up on landfills.

 

Understanding Green Roof Plants

Because of the highly fluctuating Air-to-Water ratio, experienced Green Roof designers prefer utilizing hardy plants. Ideally plants that can cope with no irrigation, that are more resistant to drought and temporary extensive water, that are more heat and wind tolerant, and vegetation that can fast regenerate after stress.

In most cases and on shallow extensive Green Roofs succulent type of plants (like Sedums) are often the preferred and common choices.  Even so the Sedum family is very large, colorful and low growing, for enhanced resilience they also rely on competition with other plant species like mosses, perennials or grasses of comparable hardy properties. Horticultural experts call this “natural plant diversity”. Such natural plant diversity stands in a full contrast to Sedum monocultures that often come with tray (modular) systems or systems with pre-vegetated mats. Pre-cultivated systems are very popular in North America where instant gratification and more revenue play a pivot role.

The variety of different plant families or allowing a natural diversity increases root activity within the Green Roof system, creates healthy rooting space, soil structure and texture, with desired micro and macro pores for enhanced soil biology, all resulting into a more ideal Air-to-Water ratio, better water retention and increasing stormwater detention.

Understanding the Current Green Roof Industry

With the focus and current trend on stormwater management, it is “natural” that many people try to improve the stormwater managing ability of Green Roofs. In this regard the Green Roof industry is not getting tired in developing a deluge of products and components that are supposed to help with stormwater management, stormwater retention, stormwater detention, stormwater neutralization, and stormwater clarification. Unfortunately most of them are forgetting about the champions; the Plants!

Interestingly many of these innovators are often highly decorated with desirable titles, have done a lot of commercial reductionist research, micro- and selective-research over a short time with floods of data, have written a lot papers that are piling up in the cloud, and they have introduced new words or terms that sound fancy, makes them look trendy or educated.

 

Learn From Common Sense

Our ancestors preferred Green Roofs as an extension of living green and private recreational space, for growing supplemental food or for building protective purposes. Today’s trend moves away from insulating purposes (because that was wrong in the first place) to stormwater management. Environmental aspects go under in the craving for a Return-of-Investment (ROI). With an entire Armada of specialty Green Roof products, with an army of engineers, and a deluge of data people are trying to narrow-down a living machine (a.k.a. Green Roof) into a static, man-made tool by altering, avoiding or eliminating natural processes which are elementary for healthy and resilient survival of plants/vegetation. It is like feeding less to livestock to reduce Methane gas emissions.    

Some of the problematic and counterproductive specialty Green Roof products are:

  • Very thick layers of synthetic fabrics with increased retention and/or detention capacity based on internal capillarity properties or hydrophilic properties. These specialty fabrics often reverse natural capillarity of engineered soils what dries out the soils faster or when infiltrated with organics particles there is waterlogging and rotting.

  • Some Retention and Detention/Drainage Boards (mainly made from plastic) have no time-release overflow or no overflow that allows air between the water reservoirs. Not talking about polystyrene plastics that are bad for the environment in all regards.

  • Water Crystals, Hydrogels are small chunks (or crystals) of man-made, water-absorbing polymers. The chunks are like sponges – they hold a tremendous amount of water by increasing in size. The liquid is then supposed to release gradually into the soil.  These products have a limited lifespan that is generally less than 1/10 the lifetime of a Green Roof and so not worth the investment.

  • Mineral Wool is a manmade material from glass fibers either spun together or adhered together. Beside that mineral fibers are a possible human carcinogen these specialty products support an Air-to-Water ratio from 95/5 to 5/95 (95% water/5% air to vice versa) whereas the strong water holding capacity /waterlogging is much longer than in natural soil profiles and creates temporary anaerobe conditions = water stress on succulent type plants and root rot.
  • High organic content (over 50%) in growth media (soil). Decomposing of organic matter increases biology activity which is related to heat, causes unusual nutrient increase or decrease, and an increase of carbon dioxide in the soil profile. This and the additional risk of waterlogging increase the stress on plants.
  • Slow release or fast release, solid or liquid fertilizers of synthetic/chemical origin behave on extreme locations like roofs very different to on-grade applications. Especially in combination with the above specialty products there could be a serious and snowballing risk for the vegetation and the environment through run-off. It can increase salt concentrations or chemical process that cause deterioration of other components (e.g. roofing) of the Green Roof or the structure.
  • Chemical weeding Chemical weeding is a common practice mostly used in North America where environmental laws and standards are very low. Chemical on extremes locations behave very different to on-grade locations and succulent type of plants that have a slower metabolism what means they might die very slowly. What looks like chemical “resident” may be affect such plants years later, weakens them and exposes them to other diseases easier.


Conclusion

Vegetation placed on ground remote or ground disconnected location is a century-old tradition for very different and combined purposes. Optimizing only the aspect “stormwater” will ultimately affect all other natural cycles within a Green Roof system. Especially in North America these considerations for natural cycles on a Green Roof are often not known, disregarded or purposeful ignored for a desperate craving of profit and ROI.

This might looks like a society accepted approach but it can result that Green Roofs in North America might not get as popular and as accepted as in European countries where commons sense, decades of monitoring, fundamental education, and solid experience is the driver for their success. Most countries in Europe understand that healthy driven plants, plant diversities and plant communities on roofs increase the benefits as they progress, develop, and generate a natural ecosystem.

End

Mineral Wool in Green Roofs – From Zero to Hero?

Green Team at Green Roof Technology, - Saturday, April 13, 2019

 Mineral Wool in Green Roofs – From Zero to Hero?

The use of Mineral Wool in Green Roof applications is an increasing trend in North America and in countries where such industry is still young or focused on fast profits rather than on longevity.

 

One selling benefit of Green Roofs is the extended lifetime of the underlying water proofing because the Green Roof protects the roofing against the elements. Can Mineral Wool stand up to this?

Against any semi scientific promotional material from Mineral Wool applicators, the market share of mineral wool in the German Green Roof construction industry is around 0.1% or out of 100 million square foot new green roof construction every year (Germany) it is only around 100,000 sf/year.

The reasons for this marginal market share are simple:

  • Mineral Wool has shown a drastic loss in performance after 5-7 years.
  • Mineral Wool is engineered for nurseries and for only one growing cycle.
  • Mineral Wool fibers are considered “hazard” in Europe.
  • On extensive Green Roofs the water retention and water-air ratio is unsuitable for succulents.
  • Mineral Wool expands and contracts in wet-dry cycles.
  • Mineral Wool is hydrophobic and can dry out the traditional overlaying growth media faster.
  • Mineral Wool growth media boards require ballast.
  • Green Roofs with Mineral Wool are difficult to repair, replant or recover.
  • Mineral Wool interrupts natural soil profiles (unnatural soil profile).
  • Mineral Wool is an additional installation step and related to higher costs.
  • Some Mineral Wool products compress under the load of ballast (soil).
  • Some Mineral Wool products contain Phenol resin or Phenol-Urea-Formaldehyde resin as binder and these products can hardly be recycled. Ecose technology is environmentally better but it doesn’t eliminate other problems mentioned here.
  • Reuse of all types of Mineral Wool for the same purpose is only possible after a (non-existing) difficult remanufacturing process.

 

An inexperienced green roof installer might like the idea of an obvious simple installation. However, what looks nice in a brochure doesn’t necessarily reflect the reality. Ballast on the Mineral Wool boards is still required and this requires different equipment. The setup costs for additional equipment are the same whether small or larger amounts of ballast ( or ballast reduces the setup costs).

Engineers might like the tremendous amount of water retention of Mineral Wool. However, they forget that plants (vegetation) have a very specific need for a balanced air-water ratio. If engineers plan the use of succulents (like Sedums) such air-water ratio is even more important (emphasis on air). Engineers are not horticulturalists.

Mineral Wool is widely used in nurseries for one-season vegetables. After this growing season the Mineral Wool (often combined with plastic) ends up on landfills. In 2008 it was around 200,000 tons of hazard waste in Netherland alone. Further, nurseries are growing their crops under highly computer controlled conditions for nutrients and air-water ratio in green houses. Who wants to sell a nursery to a building owner with roof under the sky?

In general shouldn’t we like Mineral Wool in Green Roofs? Mineral Wool gives us lucrative additional jobs in the future for repair or replacement (job security…).

 

 Photo: Repair, Reuse - impossible

I am a lifelong green roof professional and I stand up to my principals with the promise that a green roof should last as long as the building – and that the materials can be reused for the same purpose after that and without processing (there are many fancy names in advertising for it, like cradle-to-cradle etc.).

Like me many people don’t care about fancy word creation and they stand for and what the American Green Roof industry should stand for uncompromised quality and doing things right. Quick profits, instant gratification or senseless warranties don’t promote the trade of professional Green Roofers and it is certainly not my philosophy.

Mineral Wool is: From hero to zero.

 

I appreciate reading my opinion, based on 4 decades of Green Roof experience from all Green Roof friendly places in the world.

Power Plant and Green Roof

Green Team at Green Roof Technology, - Tuesday, July 10, 2018
Green Roofs and Green Walls

Since 1991 the Waste to Energy Power Plant in Stuttgart, Germany utilizes solid "old school" living green technology that the building almost visually disappears from the street level.

Old school living green technology is rather based on the long experience of horticultural experts and professional gardeners than on innovative, complicated technology that requires more maintenance than the vegetation. This drastically lowers costs, maximized resilience and increases diversity.

Old school living green technology has very long tradition in Europe, it is inherited over generation and continuously improved with man-made materials that often come from the waste stream of urban developments. 

 

Fluent Transition from Green Roof to Green Wall

Green Team at Green Roof Technology, - Friday, April 06, 2018

Fluent Transition from Green Roof to Green Wall for 23 Years



Multimedia artist André Heller created a world of wonder to celebrate Swarovski’s hundredth anniversary in 1995. Heller’s thematic centerpiece for Swarovski Crystal Worlds was the shape of the Giant. He developed the story of a Giant who set out to experience the world and all of its treasures and wonders. With this knowledge, the Giant settled down in Wattens/Tyrol, where he has watched over his Chambers of Wonder ever since.

So far, 14 million visitors from around the world have experienced the magic!

The original principle of these Chambers of Wonder is based on the historical chamber of wonders in the castle of Ambras, which was a sixteenth-century attempt to assemble a universal collection of all knowledge known at the time. In the Chambers of Wonder at Swarovski Crystal Worlds, internationally and nationally recognized artists, designers, and architects have interpreted crystal in their own unique ways. They create concepts of space and experience from the sparkling material.

Welcome to the magical world that unfolds whenever you step through the head of the Giant into Swarovski Crystal Worlds…

Visit the worlds of wonders covered under a Green Roof and protected by the Green Giant:

The subterranean world of the Giant begins in the Blue Hall, the first Chamber of Wonder in Swarovski Kristallwelten (Swarovski Crystal Worlds). Its slanted walls, painted in the color “International Klein Blue,” a shade developed by the artist Yves Klein, suggest the inside of a cave.
#greeninfrastructure #greenroofs #greenwalls #svarovski #stormwater #oldschoolgreening #sustainable #museeum

Rooftop Vineyard

Green Team at Green Roof Technology, - Tuesday, April 03, 2018

Rooftop Vineyard

Rooftop farming for educational and recreational purposes seems a fancy trend in North America.
In 2002 Dipl.-Ing Markus Wittling was planning to elevate an entire vineyard on top of the Wine Museum in Cologne, Germany. The sloped green roof spans over the entire museum building of almost 20,000 square feet. It is likely the first vineyard on a roof and the first sloped rooftop farm in the world.

In the middle ages Cologne was the most important wine trading town north of the Alps. The "Weinmuseum Köln e.V." is honoring this fact with a museum and with astonishing and educational exhibits about wine.
The green roof displays 40 of the most important grape species from around the world situated onto 720 vine stocks.
The soil layer (growing media) including granular drainage is 27 inches deep and consists of a blend of porous volcano material like Lava rock and Pumice - materials in which grapes develop their unique taste. Over 15 years of high performance.

This rooftop vineyard is a prime example of old school green roof technology and is ideal for educational purposes. If you have a chance to visit Cologne, the Wine Museum is a must on your Green Roof Safari and your effort will be rewarded with amazing wine tasting!

#greenroofs #stormwater #vineyard

Sustainability, Resilience:

Green Team at Green Roof Technology, - Friday, February 09, 2018
Celebrating two projects with 20 years of integrated Green Infrastructure.



20 years after managing the Green Roof installation in 1997 Zeppelin-Carrée (left)
and 1999 Kronen-Carrée (right).
Both buildings are covered with over 500,000 sf of multiple types of green roofs.

It is likely the world's first Solar Garden Roof.

 

It is now on Goggle Earth.

#greenroofs #biophylilla #stormwater #greenrooftechnology #greeninfrastructure #optigreen #solargardenroof

Fireworks, Green Roofs and Happy New Year! 2018

Green Team at Green Roof Technology, - Sunday, December 31, 2017

Green Roofs and Fireworks


Practically all dry organic materials are combustible at relative low temperatures. Roof shingles or many waterproofing membranes on roofs are typically petroleum-based products (including Asphalt) and there is hardly any difference to dry organic materials. Some products are equipped with chemical fire retardants that could decrease the risk of spreading fire, unfortunately not the risk of leaks cause by heat and impact.

The living vegetation of fully functional and well-engineered green roofs contains moisture and most plants (especially succulent plants on large extensive green roofs) have a fraction of the energetic potential comparing to all other components used in a building. The green roof growing media (soil for the green roof plants) is a blend of different mineral components with an organic content of typically less that 15%. It is practically impossible to set this material on fire – even when the natural moisture content is not considered.

Fires or leaks on non-vegetated roofs caused by consumer or display fireworks could have been prevented if the building would have had a fully functional green roof without mono-culture vegetation, or if conventional roofs would be well-maintained (regular removing of organic debris from the roof and gutters).

Certainly a fire is the worst-case scenario; however in most cases smoldering firework parts (and cigarettes) are only causing leaks on unprotected roofs that are discovered much later and relate to costly repair. Roof warranties typically don't cover any sort of mechanical impact and they are -again- worthless. See blog post from 2014.
See also Fire Safety on GreenRoofs

Nature is (literally) so cool.

Happy New Year!

Best Green Roof Solution

Green Team at Green Roof Technology, - Monday, October 02, 2017

The Best Green Roof Solution… by Jörg Breuning, the Green Roof Patroller

The Best Green Roof Solution Jörg Breuning Green Roof Patroller

The Best Green Roof Solution: Education & Experience

In my opinion as the Green Roof Patroller, the best green roof solution can only come from well-educated practitioners with a very long experience in selected horticultural and landscaping fields.  Over the many decades, Green Roofs have been developed from a mixture of high performance natural materials to a combination of engineered elements with natural components.

The Best Green Roof Solution Jörg Breuning Green Roof Patroller
Case in Point: “Classic” Roof Drain Cover.

Since North America was introduced to modern Green Roof technology much later than Europe, I believe only a few people understand the real basics and the evolution of this amazing landscaping/ horticultural practice on ground-remote locations.

Trial and Error System

Without understanding the basics, the North American Green Roof market is still like a kid who learns by trial and error – on the back and costs of building owners.  One problem is that every few months “new,” “revolutionary,” and “optimized” Green Roof systems are introduced.  Made of all kinds of materials that may sound good, many hardly withstand the biological activity of plants or the harsh environment on the roof for as long as the structure lasts.

The Best Green Roof Solution Jörg Breuning Green Roof Patroller
Brilliance – we don’t know what we are doing but when we mix all kind of different materials, double up drainage, and weigh it down with pavers, there should be no problem, right?

Something that may have been tested by NASA or firefighters isn’t automatically good for the plants or the environment.  The engineers or technicians behind such reinventions of the wheel might have fancy degrees.  However, many have hardly installed their own developments with their own hands on a large scale.

Long Term Research Lacking

Additionally, they never evaluated their inventions or innovation over a long enough time (more than 5 or 10 years) before making them available for the market.  I have seen people coming into this industry with a big bang and quietly leaving after a while to move up in the hierarchy of a different industry – to do the same there?

Who You Gonna Call?

The Best Green Roof Solution Jörg Breuning Green Roof Patroller
Erosion Blanket – is eroded and takes the soil down.  Sometimes a belt, suspenders, duct tape, super glue, and a nail in the belly button don’t help to hold the pants.  Buy pants in your size!

All of a sudden, the kid falls into the water well (a/k/a the Green Roof is not performing), then the building owners call for practitioners who are supposed to fix the engineers’ problems.  Building owners don’t usually call the original engineers or technicians because they can be vain.

And, when later problems or questions arise from the building owner, the engineers behind the design of the green roof don’t necessarily feel responsible anymore.  Perhaps they don’t always know the answers without Google, and these are hardly right.  In some cases they call a practitioner later; and even then, they don’t always provide the entire picture.

The Best Green Roof Solution Jörg Breuning Green Roof Patroller
The beauty of engineering – a squared box doesn’t follow a radius.

Engineers are typically not seeking for answers that discredit their efforts.  However, they try to suck out every piece of information they can get from practitioners and simultaneously avoid valuing the source because of being afraid of scratches to their polished image.

Plants vs. the Bottom Line

An additional problem is that most engineers (even at universities) are on the payroll of large corporations that are pressured to develop profit-maximizing solutions. These solutions are typically against the needs of plants – because plants don’t care about money and the stock market.

The Best Green Roof Solution Jörg Breuning Green Roof Patroller

Plants are “only” the key player on green roofs.  No happy plants = no Green Roof = no happy client.

Underperforming Green Roofs

I estimate that around 50%-60% of all Green Roofs in North America are underperforming, failing, or have been renovated, replaced, or will be going under a major renovation soon.  For Germany I would estimate this number at around 5%.  At the same time, in Europe an extensive Green Roof costs around $5/sf and in the US closer to $20/sf.

My Concerns within the North American Green Roof Industry Besides the Odd Engineering Practices?

The Best Green Roof Solution Jörg Breuning Green Roof Patroller
Ingenuity – when polystyrene plastic materials fall apart before they are installed.

1. No solid, full time practical training over more than two years before getting a professional in this field.

2. Students are not being paid during practical education – they actually have to pay a few 1,000 bucks to get a certification, like buying a certificate or a title at Walmart.

3. No innovative and large scale research over 5-10 years.  Just baby step copies and mail stamp-size research (typical research areas in Europe are 10-50 times bigger than in the US).

4. Green Roof contracts are coupled with roofing contracts (it is like buying a dryer only in combination with a fridge).

5. Low roofing quality, materials and/or inverted roof membrane assemblies (IRMA).

6. Repurposing materials that were never engineered for green roofs (e.g., in my opinion, there is no American-made drainage board that would meet my criteria and the full needs for plants).

7. Worthless single source warranties.  If you choose your own microwave, you don’t get a warranty on the fridge.

8. Greed for quick cash and/or fame.

9. Not understanding the big difference within the horticultural trades (a carrot grower is not automatically a green roof expert and a beekeeper doesn’t understands all plants).

10. Huge deficit in experienced and reliable hands-on installers and maintenance for Green Roofs.

11. Often, hands-on installers/practitioners are treated dismissively from architects, GCs (general contractors), roofing companies, or engineers.

The Best Green Roof Solution Jörg Breuning Green Roof Patroller
This makes a worried customer and a happy landfill.

Green Collar Workers

Practitioners are not Blue Collar workers, they are not White Collar workers.  We are Green Collar workers who stand above the traditional collar thinking and who have had the patience to monitor this unique living environment for decades to learn how to go beyond what is written in books or on the internet.

All the above problems have a great potential to damage the Green Roof business in the long term.  Building owners don’t want to be ripped off and each project that causes problems will change their opinion about Green Roofs in general.  While many building owners don’t want to commit to owning up to a problem on their green roof, others will spread the word among other building owners.

The Best Green Roof Solution Jörg Breuning Green Roof Patroller
The nature of nature – growing media below a plastic box with stressed Sedums. When you hire a butcher: Edging with hardly any slots; slots are too big and too high.

Ultimately, all the nice colorful brochures and great write-ups from environmental associations won’t help to change the opinion of a dissatisfied building owner, nor will it change the quality of Green Roofs.

As a practitioner I approach things very practically:

If I want a good loaf of bread, I am simply not going to the butcher.  So why do you let the butcher engineer your Green Roof?

Jörg Breuning, the Green Roof Patroller

The Best Green Roof Solution Jörg Breuning Green Roof Patroller

An Exceptional Green Roof

Green Team at Green Roof Technology, - Monday, February 27, 2017

Sufism Reoriented Sanctuary

 

An Exceptional Green Roof

After more than half a century in temporary quarters, Sufism Reoriented now has a permanent home in Walnut Creek, California. Designed under the guidance of Murshida Carol Weyland Conner by the distinguished architectural firm of Philip Johnson Alan Ritchie, the new sanctuary is set among serene gardens on three acres of land in a suburban neighborhood about twenty-five miles east of San Francisco.

Alan Ritchie’s design perfectly realized Murshida Carol Weyland Conner's vision. Brought to fruition by the Architect of Record, Soga + Associates Architect Inc, this beautiful design is to endure for over 700 years. The building is innovative in many ways, from its curved marble cladding from Carrera, Italy, to its climate control with state-of-art air filtering systems, to its Green Roof composition with 100% recycled Foam Glass Gravel  engineered by Jorg Breuning , Owner of Green Roof Service LLC , to its storm water management with rain harvesting features to retain the entire annual rainfall, to its 33 feet tall hollow bronze sculpture with seismic base isolators and acrylic butterflies, standing inside of a 3-story tall room with curved glass guardrails.


With highly experienced architectural services and project management by Clement T. Soga, Soga + Associates Architects Inc, the Sanctuary’s construction began on May 24, 2012 and its Ribbon Cutting ceremony was held on February 24, 2017.

 

Green Roof Service LLC – Green Roof Technology worked hand in hand with Sufism Reoriented, Soga + Associates Architects Inc, and SWA Group Landscape Architecture to create a Green Roof solution that perfectly mimics the natural soil horizons with materials that will last thousands of years without compromising or limiting healthy growth of any vegetation at any time. Jensen Landscape carefully implemented the details and specifications of this new type of Green Roof under the direction of Jorg Breuning.  It is the first Green Roof in North America that utilizes Foam Glass Gravel made of 100% recycled glass on a large scale.  The ultra-lightweight material performs as a drainage and retention layer combined with outstanding structural capacities. Foam Glass Gravel is produced in the USA and in Germany according to the strict specifications of Green Roof Service LLC - Green Roof Technology.      

27th February 2017

Jorg Breuning

World’s First Modular Green Roof System

Green Team at Green Roof Technology, - Sunday, February 12, 2017

World’s First Modular Green Roof System

Modular Green Roof System

Green Roof Professionals around the globe often wonder or speculate how and when the commercial modern Green Roof industry really took off. There are many opinions and alternative facts out there but only a few really know that the hot spots with patents were in Basel Switzerland and in Stuttgart Germany for seamless or wall-to-wall Green Roof systems.

The World’s first modular (or tray) system has been developed in Stuttgart by Brecht and Hämmerle, mainly known as the Brecht System (if one doesn’t consider terracotta pots on roofs as a modular system).

The Brecht System was a basic polystyrene box with a three-layer Green Roof system. The system was available in extensive, semi- intensive and intensive planting depth. With this simple three-layer system the inventor combined many benefits in one box. All systems had a water reservoir for maximum water retention – more than any other Tray system currently on the market and more than any fabrics, foams or mineral wools, and the boxes contained standard nursery soil for a healthy fast growth and to lower costs.

There were different options for covering the less attractive boxes, with either wood or metal (aluminum). Today we call these frames around the boxes: Edging.  

Based on the polystyrene, the boxes were very lightweight and easy to install. Actually, they fitted into each other to create different heights and different planting depths. I would describe them as a Modular –LEGO-like planting system.

Unfortunately, any polystyrene as a limited lifespan when exposed to UV or biological activity and so many of these roof gardens had problems after 5-10 years. Further, many of the plants rooted out of the boxes (drainage holes) and penetrated the waterproofing.

Around 1992 the last Brecht System was removed and replaced by wall-to-wall or seamless Green Roof systems. All of these Green Roofs are still existing - if the building still exists.

The Brecht Modular Green Roofs system had also other issues that are similar to the currently existing systems. However, nowadays the tray systems use metal, other plastics, and mainly with irrigation systems. This makes them last longer, but as often only delays the point of failure. The roots of plants and the biological activity on healthy Green Roofs are often underestimated as well as the functional lifespan of foams, polystyrene drainage mats, and mineral wool products.


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