Wandmalerei

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Autoren: NN

Abstract

The term ‘wall painting’ covers a great diversity of objects, and is not limited to those on vertical surfaces, but includes paintings executed on walls, ceilings, and other architectural forms. The key feature of a wall painting is that the structure in which it is housed forms an integral component of the painting itself. This support structure can take many different forms, from built structures to excavated rock cut or subterranean structures, and entirely natural formations—as in the case of cave paintings.

Einleitung

Wall paintings, from prehistory to the present day, comprise a major part of our cultural heritage. One of the most common deterioration problems affecting wall paintings is salt damage, caused by interactions between soluble salts, the environment and the material properties of the object. The susceptibility of wall paintings to salt weathering is due to the fact that, to a greater or lesser extent, they are porous. This characteristic allows moisture exchange with their surroundings, and consequently they are prone to contamination by soluble salts. Moreover, wall paintings are particularly vulnerable to salt damage because the paintlayers are located at the interface between the external environment and the microclimate within the wall. Consequently, the painting and its immediate support form the primary site for evaporation and salt accumulation. Owing to the ubiquitous presence of salts worldwide, this type of damage is one of the most widespread and commonly encountered in wall paintings conservation. Unfortunately, it is also one of the most pernicious and intractable. In addition to porosity, these objects are united by the fact that they are irremovable and require conservation in situ. This has important implications for the amelioration of salt deterioration problems. A methodological approach is required which fully takes into account not only their complex structure and material composition, but also the environmental conditions to which they are exposed. In the case of artworks located within historic buildings this demands that a balance is sought between the needs of the object, and the building users.

Schadensbilder an Wandmalereien

In general, the type of damage caused by solule salts to wall paintings is related to the location of their crystallisation. The nature of the damage varies widely—but can be broadly divided into two main categories: efflorescence (salt crystallisation at the surface) and subfluorescence (salt crystallisation beneath the surface of the object). Although visually alarming, efflorescences are generally regarded as less harmful than subflorescences, which cause the disruption and loss of the object's surface. In the case of a wall painting, the surface of the wall is the object, and the consequences of subflorescence are extreme. In addition, soluble salts also contribute indirectly to decay processes by increasing the object's moisture content, promoting the alteration of water-sensitive materials.

Literatur

Arnold, A, 1981. Salzmineralien in mauerwerken, Schweizerische Mineralogische und Petrographische Mitteilungen, 61, 147-166. Arnold, A, and Küng, A, 1985. Crystallisation habits of salt efflorescences on walls I: Methods of investigation and habits, in G Félix (ed), Vth International Congress on Deterioration and Conservation of Stone, 255 - 267. Lausanne: Presses Polytechniques Romandes. Arnold, A, and Küng, A, 1985. Crystallisation and habits of salt efflorescences on walls II: Conditions of salt crystallisation, in G Félix (ed), Vth International Congress on Deterioration and Conservation of Stone, 269-277. Lausanne: Presses Polytechniques Romandes. Arnold, A, and Zehnder, K, 1991. Monitoring wall paintings affected by soluble salts, in The Conservation of Wall Paintings S. Cather (ed), 103-136. Los Angeles: The Getty Conservation Institute. Bläuer, C, 1990. Salz und Salzkrusten, in C Segers-Glocke (ed), Schäden an Wandmalereien und ihr Ursachen. Arbeitshefte zur Denkmalpflege in Neidersachsen 8, 110-114. Hameln: CW Niemeyer Verlag. Bläuer Böhm, C, 1994. Salzuntersuchungen an Baudenkmälern, Zeitschrift für Kunsttechologie und Konservierung, 8, 86-103. Charola, A, E, 2000. Salts in the deterioration of porous materials: an overview. Journal of the American Institute of Conservation, 39, 327-343 English Heritage 1996. Wall Painting Record: Condition Audit, unpublished database of wall paintings in English Heritage properties undertaken by the Wall Paintings Section of English Heritage. Heritage, A, 1995. Imaging Dynamic Processes in Conservation; Time-lapse Video Microscopy and On-line Data Annotation', unpublished MA thesis, Conservation of Wall Painting Department, Courtauld Institute of Art, University of London. pp.124 Heritage, A, 1999. Imaging dynamic processes in conservation: on-line data acquisition and direct image annotation, in Art 99: 6th International Conference on Non-destructive Testing and Microanalysis for the Diagnostics and Conservation of the Cultural and Environmental Heritage, 17-20. Rome: AIPnD. Jeannette, D, 1997. Structures de porosité, mécanismes de transfert des solutions et principales altérations des roches des monuments, in R Lefèvre (ed), Scienze e Materiali del Larsen, P K, 1999. Desalination of painted brick vaults', PhD thesis, Department of Structural Engineering and Materials, Technical University of Denmark. Larsen, P K, 2000. Salt damage to the medieval plaster on a vault in Fanefjord Church, in P Bartos, C Groot, J J Hughes (eds), Historic Mortars: Characteristics and Tests. Proceedings of the International RILEM Workshop, 43-50. Cachan: RILEM Publications Laue, S, 1997. Einfluß des porenraums und des raumklimas auf die verwitterung von steinen durch lösliche salze', unpublished PhD thesis, Fachbereich Geowissenshaften, Johannes Gutenberg-Universität in Mainz. pp.170 Laue, S, Bläuer Böhm, C, Jeannette, D, 1996. Salt weathering and porosity-examples from the crypt of St. Maria im Kapitol, Cologne, in J Riederer (ed), Proceedings of the 8th International Congress on the Conservation and Deterioration of Stone, 513-522. Berlin: Möller Druck und Verlag GmbH. Massa, V, Pizzigoni, G, Chiavarini, M, 1996. The study of salts distribution on frescoes. A non-destructive assessment method, in F Zezza, (ed) Origin Mechanisms and Effects of Salts on Degradation of Monuments in Marine and Continental Environments, 387-391. Bari: Technomatic. Matteini, M, 1991. In Review : An assessment of Florentine methods of wall painting conservation based on the use of mineral treatments, in S Cather (ed), The Conservation of Wall Paintings, 137 - 148. Los Angeles: The Getty Conservation Institute. Matteini, M, and Nepoti, M R, 1996. Controllo analitico dei metodi di desolfatazione per la rimozione del gesso nelle pitture murali e in altri manufatti litici, OPD Restauro, 8, 66-79. Padfield, T, 1998. The Role of Absorbent Building Materials in Moderating Changes of Relative Humidity', PhD thesis, Department of Structural Engineering and Materials, The Technical University of Denmark. pp.150 Padfield, T, Bollingtoft, P, Christensen, M C, 1994. The wall paintings of Gundsømagle Church, Denmark, in A Roy, and P Smith (eds), Preprints of the IIC conference, Preventive Conservation: Practice, Theory and Research, Ottawa 1994, 94-98. London: The International Institute for Conservation of Historic and Artistic Works. Park, D, 1986. Cistercian wall painting and panel painting, in C Norton and D Park (eds), Cistercian Art and Architecture in the British Isles, 181-210. Cambridge: Cambridge University Press Pender, R J, 1999. Towards monitoring moisture movement in the support material of wall paintings, in Art 99: 6th International Conference on Non-destructive Testing and Microanalysis for the Diagnostics and Conservation of the Cultural and Environmental Heritage, 831-841. Rome: AIPnD. Pender, R, 2000. The Behaviour of Moisture in the Porous Support Materials of Wall Paintings. An Investigation of Some Environmental Parameters. unpublished PhD. thesis, Conservation of Wall Painting Department, Courtauld Institute of Art, University of London. pp.360 Piqué, F, Dei, L, Ferroni, E, 1992. Physicochemical aspects of the deliquescence of calcium nitrate and its implications for wall painting conservation, Studies in Conservation, 37, 217- 222. Sawdy, A, 1994. The Deterioration of the Romanesque Wall Paintings at Hardham Church: A Study of the Influence of Salts and Organic Coatings', unpublished postgraduate diploma dissertation, Conservation of Wall Painting Department, Courtauld Institute of Art, University of London. pp.69 Sawdy, A, 1995. The Kinetics of Crystallisation and Deliquescence of Some Soluble Salts found in Wall Paintings', unpublished MSc thesis, Conservation of Wall Painting Department, Courtauld Institute of Art, University of London. pp.99 Sawdy, A, Heritage, A, and Cather, S, 1997. St Botolph’s Church, Hardham West Sussex, Conservation of the Wall Paintings Phase I: Investigations, Recording, Treatment Testing and Assessment. Unpublished report submitted to English Heritage by the Conservation of Wall Paintings Department, Courtauld Institute of Art, University of London. pp.91 Weber, J, 1993. Salt induced deterioration of the Romanesque wall paintings in the church of St. Georgen, Styria, Austria: A case study aiming at a better understanding of the behaviour of salt systems in ancient walls, in G Biscontin, L Graziano (eds), Conservation of Architectural Surfaces: Stone and Wall Coverings, 97-103. Venice: Il Cardo. Weber, J, Leitner, H, Gaggl, W, Szambalan, R, 1996. Crystallisation of sulphate salts induced by selective salt extraction by poultices: results from a case study, in F Zezza (ed), Origin, Mechanisms and Effects of Salts on Degradation of Monuments in Marine and Continental Environments, 169-179. Zehnder, K, 1993. New aspects of decay caused by crystallisation of gypsum, Conservation of Stone and Other Materials. Proceedings of the International RILEM/UNESCO Congress, Paris, 107-114. London: E. & F.N. Spon Ltd.

Als Phase wird ein stofflicher Zustand bezeichnet, der in sich, makroskopisch betrachtet, homogen ist.