Successes and Failures in the Conservation of Wooden Structures

Abstract

The year 2000 saw the publication of two major works on the conservation of wooden heritage resources. The first, by the British wood conservation expert Brian Ridout, entitled Timber Decay in Buildings focuses on the effects of attacks by fungi and insects and on the science and technology of the development of treatments and preventive measures.1 The second, by Norwegian specialists Knut Einar Larsen and Nils Marstein, entitled Conservation of Historic Timber Structures: An Ecological Approach focuses on the development of truly multi-disciplinary approaches to the holistic conservation of historic timber structures.2 Larsen's studies in Japan have enabled this extremely useful work to focus equally on the different conservation philosophies of East and West.3These two excellent studies prompted the author to develop this paper, which reviews the development of appropriate approaches to the conservation problems of wooden structures and outdoor monuments over the last 40 years. It focuses particularly on the sometimes extreme treatments that were developed in the 1960s to treat attacks by wood-destroying fungi and insects, and the residual problems associated with these treatments. The development of more environmentally-friendly conservation treatments and minimalist approaches are also examined. The paper discusses the development of structural conservation media and methods—particularly focussing on the WER (wood-epoxy-reinforcement) and Beta systems and variations on these themes.The examples examined in the paper are all from the author's practice and 40 years of international experience, and include cases from tropical environments, Russia, Canada, Norway, the United Kingdom, and the USA. The paper has been developed from one given by the author at the American Institute for Conservation Conference in Dallas in April 2001.