Isler roof

GRP Composite panels as large light panels by Heinz Isler

Heinz Isler (1926-2009) from Switzerland was a design engineer who had been conducting research on the basis of experiments since 1954. His first development of a glass-reinforced polyester structure took place in 1956. These skylight domes with a diameter of up to 7 m as double-walled shells, he realized for his reinforced concrete shells developed in 1955. First attempts to realise a flat support structure made of GRP were carried out on a private level in his development workshop for the concrete roof of a workshop in Atelier 5, Bern, which was planned in a 4 m x 4 m grid. In the same year, 1959, he had the opportunity to create a panel of 4. 5 m x 9 m for the weekend house Dorta in Zofingen, also for Atelier 5.

The tender for a gas station roof by Moser AG from Thun, Switzerland now demanded a larger roof area of 320 m2. Heinz Isler developed a 14. 50 m x 22 m and 50 cm high GRP sandwich, which was still translucent. In 1960 the production took place on site in a tent in order to realize a high-quality project largely independent of external influences.

He applied for a patent for this design and therefore was able to realise further projects of this kind.

On the basis of our own research in the archive, eight completed projects have been identified to date. However, only the light roofs of the Säckingen/CH Rhine power plant, the roofing of a secondary school in Geislingen/D and the skylight of the Maria Regina church in Fellbach/D are known extensively. We discovered the exhibition halls of the Comptoir Suisse in Lausanne in the course of research on the Rhine power plant and another project is possibly a ceiling for a bank counter at an unknown location.

Idea: spring 1959
Prototype: Summer 1959
Patents in Schwitzerland, Austria, Germany (FRG), Great Britain
up to date 8 realisations known through archive research
Archive: GTA, ETH Zürich, Schwitzerland