ABSTRACT
Sometimes timber has to be repaired or replaced and it is useful to have some idea about the options for pretreatment. Preservative impregnation is likely to become more important in the future because efforts to grow timber more rapidly and convert it more economically are likely to reduce the durability of the end product. The current volume of timber that is treated with preservatives annually throughout the world exceeds 30 million m3 and the total annual worldwide consumption of preservatives is estimated to be in excess of 350 000 tonnes of tar and 200 000 tonnes of water-based or organic solvent-based formulations. These preservatives are expected to increase the service life of the timber by between 5 and 15 times (UNEP, IE/PAC, 1994).
