Dalles de verre – analysis and conservation

The dalle de verre technique was particularly important in post-war architecture because it was closely linked to the development of concrete architecture. It was considered to be an alternative to leaded lights and a means to transcend traditional stained glass techniques. In Switzerland, the pioneer Alexandre Cingria was one of the first of several stained glass artists to create windows using the dalle de verre technique. The heyday of this monumental art form was between the 1950s and 1980s, but earlier approaches to the technique, such the Steinsprossenfenster (stained glass windows with window bars made of reinforced cement) by Richard Nüscheler, also deserve attention.

However, after around 50 years many of these windows are in a very poor condition. Physical and chemical interactions between reinforced concrete and glass and the often exposed architectural setting pose a special challenge for the conservation of dalle de verre windows and make specific approaches to their preservation necessary. Structural-physical factors also play an important role. In selected case studies, we investigate preservation conditions and causes of deterioration and develop appropriate conservation concepts.

Project duration: 2019 – 2021

Lead
Dr. Sophie Wolf, Vitrocentre Romont

Parnters
Prof. Felix Wenk und Dr. Johannes Hugenschmidt, Fachstelle Bauwerkserhaltung & zerstörungsfreie Prüfung, Hochschule für Technik Rapperswil
Dr. Christophe Gosselin, Géotest SA, Le Mont-sur-Lausanne

Financial support
Office fédéral de la culture, Patrimoine culturel et monuments historiques
Fondation Sophie et Karl Binding
Fondation UBS pour la culture

Final report of the project (in French)
download report, annexe 1 and annexe 2

Publication
Wolf, S., Hugenschmidt, J.,  Gosselin, C. (2022). La dalle de verre: évaluation de méthodes non invasives pour le diagnostic des oeuvres menacées, in: Proceedings of the 11th Forum for the Conservation and Technology of Historic Stained Glass – 2022, 144–150 (download PDF)

Hugenschmidt, J.; Wolf, S.; Gosselin, C. Non-Destructive Testing of Dalle de Verre Windows by Fernand Léger and Alexandre Cingria in Switzerland. Heritage 2023, 6, 6311-6327. Link to the publication : https://www.mdpi.com/2571-9408/6/9/330 and PDF