Journal of Architectural Conservation

Volume 4 Number 2 July 1998

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Lincoln Cathedral west facade.

See 'Laser Cleaning Lincoln Cathedral's Romanesque Frieze' by Kay Beadman and Jane Scarrow

Contents:

Lime Mortars for Brickwork: Traditional Practice and Modern Misconceptions – Part Two Gerard Lynch

Building Repairs and the Conservation of the Painted Ceiling in the New Chapel at Ightham Mote Stuart Page

Laser Cleaning Lincoln Cathedral's Romanesque Frieze Kay Beadman and Jane Scarrow

World Monuments Watch 1996-97: Lessons from the First Cycle Jon Calame

Conservation of Granite Buildings and Monuments  D. C. M. Urquhart and M. E. Young

 

Editorial

The Thought behind the Action

David Watt

 

Antiques, architecture and conservation have seemingly become the favourite subjects of television producers and the media in recent months, and at the same time increasing numbers of historic buildings and heritage attractions are, often for the first time, opening their doors to the fee-paying public. This, in itself, is no bad thing, for the more understanding there is, the better informed people are when it comes to dealing with issues that threaten our heritage.

Raising awareness and stimulating interest does, however, require the subject to be carefully researched and well presented. These are the challenges for publications such as the Journal of Architectural Conservation, which aims to provide an essential and up-to-date resource for its readers.

The papers in this issue clearly demonstrate the importance of research in identifying problems and offering solutions for practical application. Their value comes, not just from the individual successes that they might describe, but in their wider applicability and contribution to the knowledge of those who read and study them.

The work that Gerard Lynch has done, both through his publications and training events, to increase our understanding of brickwork and the skills needed in its repair is known to many. The second part of Lime Mortars for Brickwork: Traditional Practice and Modern Misconceptions continues this important review of the subject, and focuses on some of the issues that influence our current use of hydraulic limes.

The use of lasers for cleaning architectural and art objects has received two important endorsements in almost as many months. First, there was the publication earlier in the year of Laser Cleaning in Conservation: An Introduction. Second, there is the publication of Laser Cleaning Lincoln Cathedral’s Romanesque Frieze by Kay Beadman and Jane Scarrow, also in this issue. This paper is significant, both for the clear and practical way in which it describes the application of the Q-switched Nd:YAG laser at Lincoln, and for the way in which it takes the reader through the background to its use. Both authors should be congratulated on this important contribution.

The story of Ightham Mote and of the recent works that have been so important in defining parts of its history are skilfully presented by Stuart Page in Building Repairs and the Conservation of the Painted Ceiling in the New Chapel at Ightham Mote. In this, the nature of the work and the processes of careful assessment and evaluation that led to the success of the project are explained and illustrated in a manner that leaves no doubt as to the high professional standards of those involved.

The role of academic institutions in undertaking research and providing solutions to practical conservation problems is clearly demonstrated in Conservation of Granite Buildings and Monuments by Dennis Urquhart and Maureen Young. This informative paper reviews current research, considers the effects of weathering and soiling, and addresses some of the conservation strategies that are used in response to deterioration and decay.

Whilst it is important to research the detail of a particular project or examine the various mechanisms that affect individual materials, it is similarly important to acknowledge the wider issues that affect buildings and places around the world. Jon Calame’s summary of the work of the World Monuments Fund in World Monuments Watch 1996–97: Lessons from the First Cycle clearly shows the variety of challenges that are still having to be faced and the wider remit that conservationists must take to make a relevant and lasting difference.

 

Lime Mortars for Brickwork

Traditional Practice and Modern Misconceptions – Part Two

Gerard Lynch

 

The revival in the use of traditional lime mortars for the repair, restoration and conservation of historic buildings in the United Kingdom over the past 25 years continues to gain momentum as designers and builders alike recognize the importance of using materials that are sympathetic to those originally used for the construction of such buildings. This work has tended to focus on the use of pure non-hydraulic slaked lime putties as the principal binder for all mortars, which has led both to the widely held belief that all historic lime mortars were prepared in this manner, and to a general perception that hydraulic limes are similar in behaviour to modern cements.

These views are essentially inaccurate and contradict much of the written works on bricklaying mortars that reflect the thinking and practices of architects and knowledgeable master craftsmen from the seventeenth century onwards. This is especially so in relation to the city of London, from where such influence was to spread rapidly throughout the country and to the British colonies. The vast majority of brick buildings that are now in need of care and attention date from after this period, and it is therefore timely to reappraise traditional practice and modern misconceptions.

 

Gerard Lynch  
Gerard Lynch is a self-employed historic brickwork consultant, master bricklayer and author.

 

Building Repairs and the Conservation of the Painted Ceiling in the New Chapel at Ightham Mote

Stuart Page

 

Ightham Mote in Kent is an important moated house with a complex architectural development. The sixteenth-century painted ceiling in the New Chapel is especially valuable, but has previously suffered from environmental stress suggested by flaking paint and discolouration.

The need for environmental change was acknowledged by all those concerned, and it was as necessary to safeguard the painted decoration from continued deterioration as it was to stabilize the building structure. The identification, tendering and implementation of repairs to the ceiling conditioned the contract for the repair of the whole structure. Careful study has led to further discoveries and consideration of the ceiling’s history.

 

Stuart Page Dip Arch, RIBA 

Stuart Page is principal of an architecture and interior design practice based in Tunbridge Wells, Kent, specializing in the conservation and adaptation of historic buildings to new uses.

 

Laser Cleaning Lincoln Cathedral’s Romanesque Frieze
Kay Beadman and Jane Scarrow

 

The Q-switched Nd:YAG laser has been used for cleaning stone sculptures for over 20 years, and has passed from an experimental to an accepted technique. In the United Kingdom, however, it is mainly used in a handful of major museums and research laboratories rather than to clean architectural stonework from a scaffold.

This paper concentrates on the practical aspects of a joint research project carried out between Lincoln Cathedral and Loughborough University. This involved cleaning one of the polychromed Romanesque frieze carvings in situ on the Cathedral facade. A major concern over laser cleaning is the known discolouration of certain pigments. This was pragmatically overcome by combining laser and micro air-abrasive techniques, and the relative qualities of both methods were compared and assessed. Health and safety requirements are outlined, both for the conservators and the general public.

While research continues in the laboratory to refine the laser, the success of the project so far has led to it becoming a realistic choice for cleaning the rest of the Romanesque frieze.

 

Kay Beadman BA (Hons)

Kay Beadman is senior conservator at Lincoln Cathedral Works Department. She studied sculpture at Reading University and ran her own studio in London for several years before studying conservation at Lincoln College of Art and Design. She has lectured on stone conservation at De Montfort University.

Jane Scarrow MSc

Jane Scarrow joined the Conservation Department at Lincoln Cathedral in 1994. She studied conservation at both Lincoln College of Art and Design and Bournemouth University, specializing in architectural stonework. She has worked at Winchester Cathedral and the re-building of Shakespeare’s Globe Theatre in London.

 

World Monuments Watch 1996–97

Lessons from the First Cycle

Jon Calame

 

The World Monuments Watch list of endangered cultural heritage properties has taken a broad approach to the problem of identifying and classifying conservation challenges worldwide through case studies and advocacy. Sites are ultimately listed based on their competitiveness in three categories of critical review: significance of the base resource, urgency of primary threats, and viability of the proposed response to those threats. After one full cycle of activity, including nomination, selection, grant administration and project implementation, a number of important patterns of interest to cultural resource managers emerge: many sites suffer from antipathy or misunderstanding on the part of presumed caretakers as much as physical deterioration; urgency of threats must be weighed against the nature of the resource and the thresholds of feasible repair; government agencies are increasingly unable to meet the demands of conserving the entire corpus of their national patrimony, and increasingly require material assistance from the private sector; and solutions that acknowledge the need for public/private partnerships in problem solving tend to be the most successful.

 

Jon Calame BA, MS Historic Preservation
J
on Calame is a Projects Manager for the World Monuments Fund in New York. He has a master’s degree in Historic Preservation from Columbia University’s School of Architecture, and specializes in issues related to post-war reconstruction.

 

Conservation of Granite Buildings and Monuments
D. C. M. Urquhart and M. E. Young

 

Granite is considered to be a durable building stone, but recent research has highlighted the problem of decay affecting granite used in the construction of historic buildings and monuments, and has assessed the various forms of such decay. This paper reviews some of the research work and discusses the effects of weathering, decay and soiling on granite. Conservation strategies are considered in respect of; repointing of joints, stone replacement, stone cleaning and graffiti removal, and their likely impact on the granite. Conventional conservation practice for stone promotes lime mortar as the recommended material for jointing and repointing. The role of mortars in the decay of granite, particularly mortars with a high calcium content, and their potential as a source of salts for the accelerated decay of granite in urban environments, is thought to be important. The replacement of decayed stone with new granite is now beginning to be implemented and the implications of such a policy for the conservation of buildings are discussed. Granite is not immune to the effects of stone cleaning and graffiti removal, and the potential for damage from these interventions can be significant in certain circumstances.

 

Dennis C. M. Urquhart BSc, MSc, FCIOB

Consultant building pathologist and conservation scientist, formerly Reader in the School of Construction, Property and Surveying and Director of the Masonry Conservation Research Group, The Robert Gordon University, Aberdeen.

Maureen E. Young BSc, MSc, PhD, FGS
Geologist and geochemist, Research Fellow in the Masonry Conservation Research Group, The Robert Gordon University, Aberdeen. Currently leading research into consolidant and water-repellent treatments for sandstone, stone decay and stone cleaning.

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