A key aspect in understanding how historic building and monuments fail, and how to design effective conservation solutions lies in active engagement with the knowledge base of conservation science research. Conferences on different aspects of the conservation of buildings and places provide an opportunity to look beyond the practical problems encountered on individual projects, to consider fundamental issues and the challenges and discoveries of other researchers from around the world, and also allows me to keep abreast of the latest developments in technology, technique and practice.
The 13th International Congress on the Deterioration and Conservation of Stone will be held in the University of the West of Scotland in September. This paper on granite and salt decay combined two of my research interests – how culturally significant stone surfaces deteriorate, and the deterioration processes found underwater, in the inter-tidal zone and immediately adjacent to the high tide mark can differ so dramatically from what we ‘normally’ find on buildings and monuments on dry land.
The research was based on the examination and analysis of stone from 88 monuments on the east, west and south coasts of Ireland, using non-destructive visual assessment techniques, in situ XRF analysis of stone surfaces, and detailed examination of stone using petrography, ion chromatography and the scanning electron microscope. The sites selected allowed a comparison of ‘dry’ monuments with those in the inter-tidal zone and submerged stone surfaces from a number of historic harbours (looking at the deterioration of stone from one to four metres underwater, a zone of high stresses – the specialised deterioration processes are discussed in John Ashursts Conservation of Ruins). The paper has the slightly unwieldy (but factual) title of Granite and marine salt weathering anomalies from submerged, inter-tidal and coastal archaeological monuments in Ireland. The abstract of the research is here:
Abstract of the Paper: The phenomenon of severe stone decay in coastal areas is well documented as a significant threat to stone cultural heritage in both Mediterranean and Atlantic Europe, and previous research has consistently shown that the action of salts of marine origin play a significant role in the deterioration of these stone surfaces. However, in an Irish context, a monument located on the coastline does not necessarily or even normally experience any greater degradation than a similar monument of the same stone type located in a non-polluted inland environment. Outside the harsh inter-tidal zone and the special deterioration processes found in shallow marine environments, there is often negligible difference in the rate or severity of stone decay on a granite monument built 2metres from the high water mark, with a comparable granite monument located 50metres or 50kilometres inland. Why then would coastal buildings in Ireland survive in better condition than their counterparts elsewhere in Europe? This paper presents a synthesis of field- and laboratory studies of 88 archaeological monuments and historic structures built of granite located in three of the four granite batholiths found in Ireland. The monuments and structures examined are located on the east, west and south coasts of Ireland from submerged, inter-tidal, coastal and unpolluted inland environments. The research detected particular patterns of salt deposition on granite building stones, and developed a hypothesis to explore the anomalies of salt-related granite weathering in Ireland and the significance of local distinctiveness in building conservation studies.
About the Congress: The International Congress on the Deterioration and Conservation of Stone is held every four years, and provides an information exchange forum for researchers, managers and practitioners around the world who are concerned about the conservation of cultural stone structures and objects.
The first congress was held in La Rochelle in 1972, and then Athens (1976), Venice (1979 and 2000), Louisville (1982), Lausanne (1985), Torun (1988 and 2008), Lisbon (1992), Berlin (1996), Stockholm (2004) and New York in 2012. The 13th International Congress on the Deterioration and Conservation of Stone will be held at the University of the West of Scotland in Paisley, Scotland, from the 6th to the 10th of September 2016. The attracts an international audience, with attendance averaging 270 participants presenting 150 papers. The conference proceedings have become the standard state-of-the-art documentation of innovations and developments in the field of stone conservation science.