Sunday, September 21, 2014

Mineral Wool on Green Roofs

Green Roof Innovation

Green Roof Innovation?

Mineral Wool on Green Roofs – Chance or Challenge? 

Green Roof Technology Reveals Latest Study about Mineral Wool on Living Roofs

Since their first commercial production in 1871 (Georgmarienhütte, Germany), mineral wool found its way in many applications like thermal insulation andsoundproofing. Mineral wool, mineral fibers are typically referred to synthetic materials like fiber glass, ceramic fibers and stone or rock wool
Two main types of mineral wools are on the market – water repellent (Hydrophobic) and water adsorbent (Hydrophilic). For horticultural purposes, only the hydrophilic type is useful. Many patents were granted for simple Hydroponic systems or the germination of seeds with mineral wool in the early 80’s.

In modern green roof technology the first green roof systems came on the market around 1985 in Germany at a time as the German green roof industry gained tremendous momentum. As a lightweight solution with high water retention, mineral wool seemed an ideal material. The higher costs and the higher carbon footprint - comparing to lightweight aggregates – were argued with easier installation and higher water retention.

Extensive research over more than 5 years at the University of Geisenheim and on numerous buildings confirmed the high water retention properties. However, in the mid-run these tests also revealed that the performance and the health of the vegetation were far below conventional green roof systems with standardize green roof components. Mineral wool manufacturers and green roof system suppliers stepped away from the idea of using mineral wool as a growing component for green roofs.

“Today we can see a revival of mineral wools in the green roof industry,” says Jorg Breuning, CEO, Green Roof Service LLC,” in countries with hardly any green roof experience, mineral wool is getting rather popular with potentially fatal results in the mid and long-run.”

Especially in the United States, the market is growing rapidly for mineral wools on green roofs, disregarding existing studies and without extensive long-term tests. It isn’t even proven whether certain fibers can cause health problems, leach out chemicals or whether these components can be recycled when the green roof doesn’t perform anymore.

In 2012, the lack of performance of mineral wool as a vegetation carrier resulted in a major green roof restoration at Amsterdam International Airport. 90,000 square foot of green roof – built with mineral wool - had been taken off and replaced by a standardized green roof system. At this point, this was the largest green roof restoration in the history of mineral wool on green roofs. Costs that could have been avoided.

Doing it right in the first place.

Only Natives on Green Roofs?

In 1999 North America discovered that modern green roof technology is more than just an exclusive garden for a few wealthy people on top of a building. Experts understood very quickly that there are unmatched advantages of bringing back nature into locations where it was before.
With this enthusiasm, a lot of environmentalists and environmental organizations started to notice various opportunities to improve, simplify or promote themselves in many ways. Some of these ideas might sound glamorous, but the bigger picture concerning nature, is often disregarded.
In a previous blog post we reported about the ridiculous reductionist research of comparing reflective roofs with green roofs. Today we want to focus on the hype of native plants for green roofs:
Many Americans call a living organism native if these organisms have been on this continent before North America was discovered by European settlers. In their naivety, they have completely forgotten how the Natives have discovered and have lived on the land hundreds to thousands of years before.
So called Native people did the same as any organism; they expanded from their original locations to secure the species. While migrating and expanding over continents, all living organisms will change their environment accordingly. Microorganisms like bacteria or macro organisms like humans follow in the same footprints in evolution. The migration of European settlers did that as well and eventually became 'native'.
For most American people (as mentioned on Wikipedia) the opposite of native is "invasive". This discrimination is completely ignorant to the fact that something must be introduced first before it is invasive, encroaching, or just simply trespassing. 
It is even a bigger discrimination and ignorance of God's creation or evolution (whichever you prefer) when these people ( a lot of them call themselves experts) tell us that approximately 1,000 hectares of Bamboo scattered across the USA are a problem for when they call native species. However, at the same time, 1,000,000 hectares (1,000 times more) of genetically modified corn is not a problem. On top of this blatant discrimination, these 'tunnel-view' educated people (including LEED™) are pointing out that roofs are an ideal place for what they deem native plants.
Rooftops might be a stepping stone environment for plants that have been in North America for many thousands of years but when we try and set them up in a new place it is like a conversation of a narrowed down selection of species and disregarding the entire picture. It is obvious that history repeats itself - there are still existing reservations for Native Americans and we all know what effort this was, how discriminating this was and how much diversity, knowledge and inspiration we have lost. We are essentially treating native plants in the same way and that has nothing to do with environmental protection.
These so-called native plants must have a so-called native environment and require all the natural players (other living organisms) to thrive.
* Jeffersonia diphylla for example depends on ants to spread and what building owners want to have colonies of ants?
* The big family of Trifolium (stamped as a weed by nurseries) requires the stiff hair of animals to fulfill their natural calling - how many deer of bears do you want on your roof?
* Or shall we shoot all the birds that spread seeds from introduced trees?
The point of this blog is that any type of nature is better than covering the ground with impervious surface areas like asphalt, concrete of ground mounted solar factories. All our environmental issues are caused by the loss of natural environments. It is also much cheaper to protect these natural environments where they are and avoid relocation into reservations (such as rooftops). Simply by reducing footprints of man-made structures and concentrating human settlements to specific location allows these so-called natives organisms to thrive and to continue their journey of evolution.

Sunday, August 4, 2013

Fireworks and Green Roofs

Fireworks and Green Roofs

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 they is hardly a difference to dry organic materials. Some products are equipped with chemical fire retardants that could decrease the risk of spreading fire, not the risk of leaks cause by impact

The living vegetation of functional and well-engineered green roofs contain high moisture contents 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 – not even considering the natural moisture content.

Many fires or leaks on roofs caused by consumer or display fireworks could have been prevented if the building would have had a fully functional green roof or a well-maintained conventional roof (regular removing of organic debris from the roof and gutters). 

A fire is the worst-case scenario; however in most cases smoldering firework parts (and cigarettes) are causing leaks on unprotected roofs that are discovered much later. These problems are unknown on functional green roofs. When a green roof prevents a leak or even a fire it is typically not recognized but the payback is right there. 

Nature is (literally) so cool.

- Jörg Breuning welcomes people who want to learn from decadesof green roof experience -