Above the streets of Manhattan, tourists stroll alongside New York joggers on a path flanked by abundant vegetation. There is an unobstructed view of the Hudson River to the east, while to the west you can watch the hustle and bustle of the city. The High Line Park was once a freight rail line but was abandoned in 1980 and forgotten. But thanks to an urban development competition in 2001 that called for the redesign and simultaneous preservation of New York's High Line, the heart of Manhattan has been home to the world's longest green roof of 2.3 kilometres in length for more than five years now.
"The New York High Line is a perfect example of how a concrete jungle can be transformed into a wonderful site", says Joachim Stroh, head of marketing at Nürtingen-based green roof company Zinco. Zinco provided the green roof system build-up for the project, the heart of which is made up of the drainage elements. They ensure the balance of water and ventilation and also store water or drain off any surplus water.
Zinco from Nürtingen is one of the world's leading companies for green roof systems. From ecological protective coverings in conjunction with a photovoltaic system to roof gardens and green roofing of underground car park roofs with pathways or driveways, Zinco develops customised solutions for all types of roof usage. "Our core competence involves system build-ups for classic green roof systems", says Joachim Stroh. One advantage of green roofs is that they retain rain water. In densely populated urban conurbations, they help to compensate for lost green spaces. They are beneficial for the urban microclimate and reduce the burden on overworked sewage systems.
The company began as a plumbing business founded by Walter Zink in 1957. The company founder and boss was often to be found on roofs, because in those days the roof edge trims made from sheet metal had to be adjusted individually. At some point the plumber had had enough of the sight of grey and boring roofs. "He was also inspired by the architect and artist Hundertwasser", explains Stroh. And so, a good decade later, the plumbing business was transformed into an innovation driver for sustainable construction.
Adopting the motto "From flat roof to roof garden", Zinco started in 1972 to develop green roof systems on a broader scale with the involvement of third-level institutions. Since then a string of innovations has followed, characterised chiefly by an ecological way of thinking. For example, since 1990 Zinco has been using recycled clay brick as the raw material for its roof substrate instead of lava recovered centrally in the Eifel region of Germany. "The production sites of our fifteen partners are distributed decentrally across Germany, thus reducing transportation distances", explains Stroh. Another milestone was the integration of solar technology in green roof systems. "Solar modules in conjunction with green roof systems offer higher efficiency. The ideal surrounding temperature for solar cells is around 25 degrees. Thanks to evaporation by the green roof system, this temperature is easier to achieve than with a gravel roof", says the marketing chief.
Not only does Zinco export abroad, it also has partner firms and branches around the globe. These locations also include countries with specific climatic conditions. "In Iran you simply need more irrigation. In that part of the world, solutions are required that prevent the additional water needed from just evaporating again", says Stroh. The internationalisation process is also gaining pace: "Sustainability is playing an ever-increasing role in urban planning in conurbations." From Amsterdam Airport to shopping malls in Turkey, the University Library in Warsaw, Subaru's headquarters in Singapore and the Repsol Tower in Buenos Aires - the list of international projects is indeed a very long one.