The aim of this project was to prepare a draft Conservation Management Plan for Kanturk Castle, Co. Cork, an Irish Renaissance palace, on behalf of An Taisce. The plan was to consider the key conservation issues affecting the castle, and also to investigate the issues and impact of tourism development. Conservation Management Plans provide an understanding of the significance and vulnerability of a place, and provide guidelines, together with a set of specific actions for the management of that place for future generations. They aim to balance responsibilities to protect, conserve and enhance the natural and cultural heritage of a place with active and creative policies to facilitate access and protect its significance for now and into the future.
The existing literature and knowledge across many disciplines, including stone conservation and heritage management, is founded on an ability to react and adapt to changing situations, based on the knowledge and experience gained through past and current events. However, both reactive and anticipatory responses to threats to buildings are largely based on the premise that the past is the key to the future. predicted rapid changes in climatic conditions anticipated throughout the 21st century, results in a situation where past events can no longer be relied upon for driving future decision-making. Many of the established truisms and work practices of stone decay, cleaning and conservation may have to be amended, altered or abandoned when confronted with new challenges.
The existing stone conservation literature is too-often centered on understanding stone deterioration and providing appropriate solutions on a very simplisitic basis. Stone conservators are focused on solutions for ‘limestone’ problems and ‘sandstone’ problems, though these are very complex materials, containing sub-types of widely varying stone properties, durabilities, and responses to soiling and new environmental conditions. As the 21st century progresses, heritage professionals will see more complex interactions between stone decay and soiling processes and changing environmental conditions. There is a need for growing interaction between heritage professionals to respond to increasingly complex future architectural conservation problems. There will be a number of key shifts, which cannot currently be accurately quantified, but can be flagged as areas of concern. These include: Continue reading
Stone in buildings is exposed to natural patterns of weathering, varying urban conditions, a legacy of repair and change, building quirks and outside events that interact in complex in complex and sometimes unpredictable ways to produce new patterns and new rates of stone decay. Stones can also have a ‘memory’ of the legacy of structural and chemical changes it has undergone since before it was quarried – legacies which can explain why stone continues to deteriorate long after air pollution levels have improved. Further, different stones react differently to different stresses, and require different solutions. A necessary part of building the knowledge to make informed decisions to conserve stone buildings is to understand why and where stone decay can and does occur.
The aim of this stone conservation research project was to gather information on the degree of degradation and erosion of stone monuments in the Republic of Ireland dating from the Neolithic through to the nineteenth century. The study examined 112 archaeological monuments in 14 counties, identifying and assessing the most significant forms of decay and impacts to stone monuments based on factual up-to-date information gathered through fieldwork and laboratory analysis. The archaeological monument types dated from the Neolithic to the nineteenth century and included megalithic tombs, cashels, Anglo-Norman castles, medieval tower houses, post-medieval buildings, and ecclesiastical heritage including churches, abbeys, round towers, high crosses and a range of smaller stone monuments including crosses, a cursing stone, leachta and grave slabs.
The most significant results and conclusions of the study are: Continue reading
The aim of the project was to re-examine c. 100 stone monuments a decade after the Stone Monuments Decay Study 2000 to establish what (if any) any changes had occurred in their condition. Many things have changed in Ireland over the intervening decade, including unprecedented development within the Irish landscape, developments in the techniques and practice of conservation work, changing attitudes to archaeological sites and historic buildings, a growing awareness of the potential wide-ranging impacts of climatic change, and recession which had dramatic impacts on the construction and conservation industry. Within this context, the study sought to determine the condition of a series of archaeological monuments and historic buildings, and investigate changes to the sites and the monuments, and how weathering and soiling patterns on their stone surfaces have progressed over time.
The original project highlighted the vulnerability of a cross-section of Ireland’s historic buildings from prehistoric tombs to medieval medieval castles and ecclesiastical heritage, such as churches, high crosses and round towers, to post-medieval fortifications such as Martello Towers. The new project allowed a unique opportunity: to study in detail how buildings, stone surfaces and carved stone sculpture have changed over a decade. Continue reading
The aim of this research project, undertaken through the Dublin Institute of Technology, was to explore, evaluate, compare and contrast the vulnerability to physical decay and deterioration of archaeological and architectural stone monuments located along the Irish coast, with those found in unpolluted inland environments. The usefulness of the coast and rivers for the exploitation of natural resources, trade and communications resulted in the historic development of towns, villages, individual buildings, monuments, structures and complexes along the coastlines of the world. The legacy of Irish archaeological monuments and historic buildings built in stone and found in close proximity to the coast ranges from the earliest tombs and ritual complexes to the wealth of medieval towns, fortifications and ecclesiastical settlements, through to the increasing diversity of post-medieval and 20th century cultural heritage, much of which has been constructed in stone. The coast is a dynamic system, an interface between land and sea where rapid change can have devastating effects on historic buildings and monuments. Damage to stone monuments can encompass submergence of entire sites, to undermining and physical damage of structures at the waters edge, to severe decay of historic stone surfaces: an area which has been the focus of significant academic interest and research elsewhere in Europe. Continue reading
The aim of this project was to investigate a possible early medieval trade network in high status stone for Irish High Crosses in the kingdom of Brega in north Leinster, and consideration of how such trade informs our understanding of the relationship between ecclesiastical settlements, natural resources and cultural identity. The objectives of the project were to identify the source of the stone, to plot the distribution of the original quarry and the ecclesiastical sites where it was used, and to critically evaluate the archaeological implications of this information and how it can contribute to our understanding of masons and decorative stonework in early medieval Ireland. The study used NDT techniques to characterise both the stone and weathering processes of sculptural and decorative architectural stonework. Potential quarry sources and rock outcrops across the kingdom of Brega were visited, sampled and analysed using petrographic and geochemical analytical techniques.
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. Continue reading
Materials research and analysis has been a core activity since 1997, focused on understanding the deterioration and methods of preserving the historic fabric of architecturally and archaeologically significant buildings and monuments.
The knowledge of stone, brick mortar, plaster and render types and how they deteriorate has been gathered through primary research funded by government bodies and third level institutions, as well as research studies commissioned by architects, engineers, archaeologists and building owners to address the deterioration of historic buildings, archaeological monuments, ruined structures and finds from archaeological excavations. Work undertaken since 1997 includes:
- Identification, Characterisation and Matching of Stone, Brick, Terracotta, Mortars and Plasters
- Diagnosis of Historic Building Material Failures (e.g. stone decay, staining, weathering, past cleaning treatments)
- Studies of Provenance, Technology and Dating of Archaeological Building Materials
- Primary Research funded by Government Bodies into the Nature, Origin and Deterioration of Stone, Brick and Mortar
- Testing of Conservation Techniques for Cleaning, Consolidation, Stone Treatments, Biocides and Repointing
- Recommendations for Conservation & Preparation of Specifications
- Design of Replica and Improved Mortars and Plasters
Pavía, S, & Bolton, J. (2001) Stone Monuments Decay Study 2000: Assessment of the degree of erosion and degradation of stone monuments in the Republic of Ireland. Kilkenny. The Heritage Council
Pavía, S, & Bolton, J. (2000) Stone Brick and Mortar: Historical Use, Decay and Conservation of Building Materials in Ireland.Bray. Wordwell Books
Bolton, J. (2016, forthcoming) “Granite and marine salt weathering anomalies from submerged, inter-tidal and coastal archaeological monuments in Ireland”, Proceedings of the 13th International Congress on the Deterioration and Conservation of Stone, Paisley, Scotland
Bolton, J. (2012) “Ever decreasing circles: the implications of climate change for the deterioration of coastal archaeological monuments”. In IKUWA 3: Beyond Boundaries. Proceedings of the 3rd International Congress on Underwater Archaeology, University College London, 10-12 July 2008. Frankfurt. Roman-Germanic Commission of the German Archaeological Institute. Pp.143-150
Bolton, J. (2010) “Carved stone in Romanesque Ireland: use, decay and conservation”, 7th International Conference on Science and Technology in Archaeology and Conservation Workshop on Documentation and Conservation of Stone deterioration in Heritage Places Petra, Jordan, December 7 to 12, 2010.
Bolton, J. (2010) “Irish Medieval Mortars: Implications for the formulation of new replacement mortars”, 2nd Historic Mortars Conference & RILEM TC 203-RHM Repair Mortars for Historic Buildings, Prague, 22-24 September 2010. Czech Republic. Institute of Theoretical and Applied Mechanics & RILEM. Pp.19-28
Space and Settlement in the Middle Ages in an annual international, interdisciplinary conference exploring all aspects of human settlement and the use of space throughout the Middle Ages, focusing primarily on new and emerging research into space and settlement in medieval Ireland.
The 2015 conference will be held in Trinity College Dublin on May 22nd & 23rd 2015, and focuses on buildings, recent excavations and discoveries, re-interpretation, bioarchaeology, and approaches to medieval space and settlement in the Digital Age. I will be presenting a paper on early medieval architecture entitled “Harvesting the landscape: the stone mason in early medieval and Viking Ireland”.
Historic graveyards provide us with landscapes of cultural, historic and natural interest, and often remain in use. Irish historic graveyards may contain a wide range of monuments such as headstones, ledger slabs, box tomb chests, allegorical sculpture and mausoleums. Many graveyards are also archaeological monuments, retaining much earlier burials and structures and so require special consideration and consents for necessary repair and conservation works.
Deterioration and weathering are inevitable parts of the history of a monument, and the principles and techniques Continue reading