Maintenance of Material Conditions

The Decay, Weathering and Physical Maintenance of Historic Monuments

Egypt, West Thebes, the Temple of Hatchepsut. Project: weathering and maintenance of sandstone in West Thebes. (Photo: A. Arnold, Institute for the Preservation of Historical Monuments and Sites, 26.2.92)

The work of the technical laboratory rests upon long-tested, continuously developed, internationally desirable methods of study and evaluation in the examination of damage wrought by weathering, especially by dampness and salts.
The work is tied to practice and to the individual building. In collaboration with preservationists, architects and restorers, the process of weathering is identified, followed and analysed by means of the continuing observation and measurement of various climatic parameters and by laboratory analysis. Realistic and individual maintenance and restoration concepts are thereby developed.
One particularly important focus which is in the process of being broadened at the moment is the development of methods for the long-term preservation of monuments, meaning the prevention (resistance to damages) based upon an analysis of potential threats.
The projects are co-financed by building-specific credit granted by public institutions (for example, cantons). The most significant objects of activity are: the Müstair monastery GR, the Grossmünster in Zurich, the Zillis Church (painted timber ceiling), the Church of Tenna, the Chapel Kyburg, the Basle Münster, the Abbey of St. Maurice (Le Martolet). Foreign projects: consulting for study projects of the German Federal Ministry for Research and Technology, studies of the Temple of Merenptah in Qurna, West Thebes, Luxor, Egypt. (Contact: Dr. Andreas Arnold, Dr. Konrad Zehnder, Andreas Küng, Oskar Emmenegger)

Stucco Work on Historic Buildings
Begun some twenty years ago, the ongoing compilation and research on the techniques and surface structures, as well as on the decorative use of historical stucco work in Switzerland and adjacent countries since the Middle Ages through to the 19th century will be prepared as a travelling exhibition and a catalogue. (Contact: Oskar Emmenegger)

Frescoes

• Study of painting technique, the phenomena of damages and their causes. The studies serve to underpin each individualised restoration concept and to provide general knowledge of destructive mechanisms, strategies of damage prevention, and possibilities for protecting wall paintings. In addition to commissions granted by the cantons or the Federal Commission for Historic Preservation for work on buildings in this country, many foreign commissions have been received: a scholarly collaboration in the project "Damages in Frescoes" (German Federal Ministry for Research and Technology) which includes co-operative efforts on various restorations (Old Idensen Church, Church of the Holy Ghost, Lübeck).
• As part of a collaborative undertaking with historic preservationists in the southern Tyrolean region (Italy, Dr. Helmut Stampfer), the frescoes comprising the singular High Mediaval Iwein-cycle in the Rodeneck Castle near Brixen are being studied in terms of their painting technique and art historical significance. The results of this study are now being reworked for a comprehensive publication on the fresco cycle. The first section will cover the Carolingian and Romanesque frescoes. (Contact: Oskar Emmenegger, Dr. Andreas Arnold)

Technology of Mediaeval Stucco Work
Figurative stucco work from the Middle Ages is of particular worth. The stucco work still in situ in Switzerland, Germany, Italy and France as well as the archaeological finds in the collections of museums and departments of preservation has thus far been inadequately researched, if at all. At the same time, many pieces are inadequately secured in terms of conservation so that their very physical substance is endangered. A group of experts from the countries already mentioned are preparing an exhibition, under the direction of conservator Dr. Brand, on the art treasures in Hildesheim which have already been evaluated (Cathedral, St. Michael's, Diocese Museum). An accompanying publication on the art-historical significance, the technological peculiarities and the coloration of Mediaeval stucco work is planned. (Contact: Oskar Emmenegger)

Evaluation of Archaeological Finds from the Church of Martigny
The late Romanesque and early Mediaeval finds from the Church of Notre-Dame-des-Champs in Martigny VS, in which the early Christian bishop's church of the Roman settlement Octodurus was found, the oldest bishopric on Swiss territory to be mentioned in written sources, are being evaluated in the context of a graduate thesis project. Because the earliest church was no more than a restructured Roman villa, the primary issue to be explored is that of the role of the renovation and re-programming of Roman buildings in the genesis of Christian sacred architecture. Third-party financing. (Contact: Dr. Hans-Rudolf Meier)

Müstair (Grisons), Monastery Church of St. John, Carolingian frescoes. Project: weathering and maintenance of frescoes. Electron microscope image of a stucco layer; image width ca. 30 micrometers. (Photo: K. Zehnder, Institute for the Preservation of Historical Monuments and Sites, 30.1.96)

Archaeological Study of the Monastery of St. John, Müstair
Part of the work involved in the programme Müstair was assumed at the Institute's inception. This work continues to be a focus of study, with the following intentions: archaeological examination of the entire monastery complex in order to establish with certainty its building history and to prepare restorative work, and education of scholars and students.
The state of research up to 1995 has been published: The first part covers the primary stages of the complex's building history and development, as far as this has become recognisable. The second part describes the final stages of work on the late Bronze Age timber structure with its minor finds. Three large complexes remain to be studied: the buildings around the north courtyard, the older buildings, to some extent proven but also presumed to exist to the north and the east-south-east of the existing monastery, the church itself. Before archaeological studies of the church can begin as preliminary work for the restoration, the optimal conditions for the future preservation of its frescoes will be established based upon microclimatic measurements (technical laboratory of the Institute for Historic Preservation). A six-year programme has been developed for the monastery complex. A second programme (circa 6-7 years) encompasses the reworking of results derived from residential and work-related buildings.
Methods: increasing use of CAD. Financing via the Swiss National Science Foundation and the ETH, contributions in the past few years from the Federal Department of Culture and, since 1994, from the Canton of the Grisons. (Contact: Prof. Dr. Hans Rudolf Sennhauser, Dr. Jürg Goll, site director)

Zurzach, Historical-archaeological Register
Work which began in 1966 is being continued without any significant changes in its aims and methods. Great progress has been made in the indexing of written source material which can be documented systematically with the use of computers. Status of the work: Following the main street façades, the façades along the by-lanes have almost entirely been recorded. A greater number of buildings and renovation could be dendrochronically dated. In the upper part of the village, the systematic measurement of the ground floor has nearly been completed. CAD is being used increasingly for the documentation. (Contact: Prof. Dr. Hans Rudolf Sennhauser, Alfred Hidber)

Surveying and Topography
Continuing work on the development and conveying of surveying methodologies which are tailored to the particular needs of archaeology and the study of buildings (in co-operation with cantonal archaeologists and preservationists as well as with the Institute for Geodesy and Photogrammetry of the ETH). Modelling techniques applied to significant domestic and foreign digs, often involving participation on interdisciplinary research projects and, whenever possible, in combination with the training of assistants in situ.
Most important sites: Eretria, Greece (University of Lausanne), Brig-Glis VS, Gamsenmauer (W. Drack), Cama GR, Norantola (L. Högl), Kerns OW, Melchsee-Frutt (W. Meyer), Oberbipp BE, Digital Terrain Model (H. R. Sennhauser), Schaffhausen, Schweizersbild & Rosenhalde (M. Höneisen), Untersteckholz BE, Kirchmatt (J. Goll). (Kontaktperson: Rudolf Glutz, Solothurn)

Restoration of Older Buildings - Case Studies for Practical Implementation
The approximately 200 000 historic monuments in Switzerland are buffeted by the forces of the market economy, building regulations, historic preservation and ecology. They are consumer goods, objects of legalistic consideration, historical documents and resources in one. Their continued existence is based on a successful harmonisation of all these areas. In the interest of maintaining these witnesses to history, historic preservation is largely responsible for analysing the various limited interests and combining them into a synthesis. To this end, a set of tools oriented towards practical implementation is developed with reference to concrete cases of full reconstructions: the correlation of technical measurements and preservationist interests, the development of reconstruction purposes in compliance with the structure of older buildings, the transposition of these aims into optimal built measures. These renovation concepts, developed in part during blocks of courses (continuing education) with experts and students, are evaluated didactically and thereafter further developed. The aspects which are pursued in an exemplary manner are densification in residential areas, durability, legibility and reversibility of the interventions and new models for defining damage. (Contact: Martin Stampfli)