Timber preservation in New Zealand: an overview of the industry

Abstract

This report is in two main sections. The first is an overview of timber preservation in general, the aim being to give the reader an understanding of timber preservation so that the New Zealand industry can be viewed in perspective. It explains why preservatives are used and the types of protection which can be obtained to extend the life of various species of timber. Techniques and preservatives are discussed with reference to their history, application, characteristics and popularity, covering pressure and non-pressure systems for tar oils, waterborne and organic solvents. The second section is a more detailed view of the industry in New Zealand. This covers the various techniques used, types of chemicals, levels of treatment and development of various processes. How the Timber Preservation Authority controls the industry, its legal position, quality control and enforcement is looked at with reference to their 1986 Specifications. The state of the industry is also studied including the numbers, types and location of plants, recent developments and direction the industry is taking. The aim of the report is to give the reader a general understanding of the timber treatment industry in New Zealand while avoiding much of the detailed information which is relevant only to operators of treatment plants. However sufficient referencing is given to allow this information to be readily obtained in the relevant Specifications, Standards and Codes of Practice.