SilverJet Katschberg: a green roof with regional plants

Roofing for mountainside facilities is among the most challenging for two important reasons:  the design of the roof and the logistics that will characterise the development of the project itself.

As far as design is concerned, roofing systems in mountain areas require more attention than those designed for commercial buildings in urban areas, such as shopping centres, shops and hotels. Extreme weather conditions must be taken into account when choosing roofs for ski resorts on high mountains.

Since temperatures fluctuate greatly even within a few hours, it is important to assess the thermal context during the definition phase of a pitched or flat roofing system. This makes it necessary to assess the roofing components properly in order to calculate the right composition of the roof in terms of insulation and covering. The choice of a flat roof may also suggest exploiting the roof space to create functional spaces for other activities: gardens and terraces or systems for recovering the water that may be generated during the different cycles of the day. 

In the case of SilverJet Katschberg, focus was on the choice of vegetation, which had to be the same as that existing on site. In order to meet these requirements, work was therefore done to ensure that the green roof chosen would help to make the building less intrusive.  When choosing a roofing system at a high altitude, another important point is the logistics and supply of materials for its construction and maintenance. Having chosen a green roof has in fact allowed the ski resort to reduce the impact of management and upkeep of the roof over time, ensuring safe operation of the resort and isolation of the gondola lift machinery.

The 8-person Silverjet gondola lift has set another milestone in this ski resort.  The station at the bottom is characterised by a particularly ecological feature.
The facts relating to the new cableway from St. Margarethen in the Lungau region to the Aineck speak for themselves:  The journey time to the summit has been reduced from 15 to 7 minutes. A total of 2,600 passengers are transported per hour – at a speed of 6 metres per second. The gondola lift also makes transporting children and foot passengers easier.

A special feature of the Silverjet project, that cost 12 million Euros, is the extensively planted roof of the station at the bottom. Only plants from the region were planted, as Christian Schlick, CEO of Lungaudach roofing and tinsmithing company, reports: “We were given the seeds by Tamsweg District Administration. Everything was organised by the Society for Nature Conservation, and is a truly great idea.”

Work on the gradient insulation underneath and the corresponding drainage outlets were not quite as easy as planting the roof. “We had to install 9 gullies to guarantee efficient drainage. That was tough and complicated because the building has a futuristic design, with all its curves, wall projections and holes”, explains Schlick. The fact that the bottom station laying work turned out perfectly can be seen in the pictures – and nature is happy, too, of course.

Client | building contractor: Katschbergbahnen GmbH 
Site supervision: Thomas Bogensperger
Roofing technology: Lungaudach GmbH, Mariapfarr
Location: 5582 St. Margarethen, Silverjet 1 bottom station
Year of construction | completion: May to November 2018 Sealed area: 2,265 m²
BMI Villas products | systems employed: Pormex-Rapid, Hydrostop Multi 5, Villasub EKV-15 NSK, Elastovill E-KV-4, Elastovill E-KV-5, Villaverde E-KV-4 wf, Villaverde E-KV-5 wf, Elastovill E-KV-5 S, Villaself E-4 SK-SI