Timber Preservation: The Potential Use of Natural Products and Processes

Abstract

Timber represents a rich source of potential nutrients for a wide variety of macro-organisms (e.g. insects and marine borers) and micro-organisms (notably fungi and bacteria). Timber is susceptible to these agents during both production and in-service use, though degradation by them is not always inevitable and is usually associated with misuse or inappropriate use. However when timber is to be used in some types of environment, notably where relatively high levels of moisture are available, protective systems are necessary to prevent decay. Currently such systems often rely on the use of chemical treatments but alternative strategies are under development at a number of centres and these come under the headings of environmental control, biological control and the use of natural products as wood preservatives. This chapter will explore each of these systems in the context of the control of the dry rot fungus Serpula lacrymans,a wood decay basidiomycete which causes severe damage to wooden elements of buildings in temperate areas and whose natural home appears to be the Himalayan foothills. Discussion of these natural processes and products will be preceded by a description of the current wood preservation scenario and of the pressures which are bringing about change in the associated industry.