Window installation at dizzying heights

08/11/2022 | Print view

Window installation at 2,244 metres also places particularly high demands on the products. Several superlatives apply to the mountain station of the Karwendel cable car, and the window installation was also particularly challenging - but with illbruck sealing components, the elements could be installed quickly.

At the edge of the Karwendel mountains lies the western Karwendelspitze, a 2,385 metre high mountain on the border between Bavaria in Germany and Tyrol in Austria. Visitors reach the top with the Karwendelbahn, Germany's second-highest cable car.

The mountain station houses a restaurant, an event hall and, incidentally, the giant telescope, which towers far above the cliff edge and informs visitors about the high-altitude habitat with various displays. Another attraction is the highest brewery and distillery in Germany.

In three construction phases, the breathtaking view will be enormously enhanced by installing floor-to-ceiling all-glass window systems. The entire building is being renovated with high-quality aluminium window and door elements by the company MarStein GmbH from Leutasch/Austria.

Even the construction site logistics were challenging. The windows were transported to 2,234 metres by helicopter and the remaining materials by gondola.

The airtight building envelope was a compulsory exercise. Due to the sometimes extreme weather conditions to which Germany's second highest mountain station is regularly exposed, the demands on the systems used with regard to driving rain and air tightness were correspondingly high. Not only the windows themselves, but also their professional installation, including sealing, play a special role. This is because connection joints between walls and windows can quickly become weak points. The three sealing levels are decisive in this context: To the outside, the joints must be driving rain-proof and open to vapour diffusion, in the middle area they must be heat and sound insulating and to the inside they must be airtight.

Together with the illbruck technician, Martin Steinkasserer, one of the two managing directors of MarStein, decided on the multi-functional tape illbruck TP654 illmod TRIO 1050 from the illbruck i3 window sealing system. It covers all three sealing levels at the same time and ensures a high level of air tightness, 100% better than required by the standard, and driving rain tightness up to 1,050 Pa.

It thus exceeds the requirements of DIN 18542-MF1. The strength of the tape is due to its unique geometry (patent pending). The required continuous airtight layer is ensured by TP654 illmod TRIO 1050 on the one hand by the membrane within the tape, and on the other hand by the two grey layers, which ensure continuous contact with the wall and the building element.

The required continuous airtight layer is ensured by TP654 on the one hand by the membrane inside the tape, and on the other hand by the two grey layers, which ensure continuous contact with the wall and the building element.

Windows delivered by helicopter

The implementation of the renovation was very challenging. It started with the construction site logistics. For example, the windows were delivered to the site by helicopter and the rest of the materials were transported to 2,234 metres by gondola. Due to the orientation of the mountain restaurant, it was not only a matter of professional installation, but also of securing the players correctly. This is because some of the windows had to be installed at dizzying heights above a rock face. In addition, work had to be done quickly in the wintry conditions in November.

See also: An alpine hut like a pinnacle

The multifunctional tape illbruck TP654 illmod TRIO 1050 was also convincing in this case. This is because the tape can be installed quickly and independently of the weather, as the outer, middle and inner seal is realised in just one work step. In addition, thanks to the special surface structure of TP654, the window can be easily inserted into the reveal. Another processing advantage is the possibility of using the tape on both sides, which eliminates the possibility of confusion (inner and outer side) during installation. Due to the wide range of applications, logistics are also simplified and fewer products have to be transported to the construction site. A real advantage for a construction site at an altitude of over 2,244 metres.

The unique - patent pending - geometry with 100% airtight membrane inside and 100% airtight grey foam on the outside.

For the connections under the window sill - the water-bearing level - the installation professionals from MarStein relied on the ME501 TwinAktiv HI window and façade film in combination with the universal hybrid adhesive SP036 and the FM210 window and façade foam from illbruck. The film is particularly tear-resistant, waterproof, airtight and resistant to free weathering for 12 months. Due to its variable sd value, it can be used indoors and outdoors and fulfils the recommendations of the RAL Quality Association for Windows and Front Doors.

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With the completion of the window renovation, Germany's second highest mountain station with its attractions is fit for the requirements at over 2000 m and offers visitors a generous view of the surrounding high mountains.