BRE IP2/01 PDF

Introduction

The required service life of timber used in construction is usually specified in decades. Different timber species vary in their natural resistance to attack by wood-destroying fungi and, where necessary or desirable, the natural durability of timber can be enhanced by preservative treatment. Since 1929, BRE has maintained a programme of continuous field testing to provide performance benchmarking of the natural durability of important commercial timber species and to assess wood preservatives used by industry. The results derived from these tests constitute a national database that can be used to evaluate and predict the likely performance of new products and processes for improving the durability of timber used in construction applications as they are developed.

Timber used out of contact with the ground, as in joinery, is at a lower risk of decay than timber in direct contact with the ground. Nevertheless, timber of low durability will require preservative treatment to ensure satisfactory service life, and appropriate preservatives have been developed for this specific application.

Environmental concerns about the use of chemicals and about organic solvent emissions into the atmosphere are driving the adoption of alternative active ingredients for wood preservatives and the wider use of water-based preservative formulations. Before the performance of these can be accepted with full confidence, it is essential that all new products be fully evaluated and compared with proven commercial products to ensure that they are all fit for their purpose.

This paper describes the current status of trials started between 1982 and 1994 using the methodology described in British Standard BS EN 330:1993, with treatments applied to both Scots pine sapwood and spruce.