Timber treatment or wood preservation refers to all the actions that are taken to guarantee a long life of wood fall. Apart from chemical processes and preservatives also called as lumber treatment or timber treatment, there are different structural wood preservation procedures for extending the life of timber, wood, engineered wood or wood structures. These processes are generally employed to increase the resistance from destruction by fungus or insects, and durability. In chemical preservation, lumber or timber that has to be treated by preservative is generally applied using pressure or vacuum treatment. The preservatives that are used to treat timber by pressure treatment are referred as pesticides.
Treating timber helps in providing long term resistance to organisms causing deterioration. It helps in ensuring the long life of the timber by seven to ten times when applied properly. But if it is not treated, the wood that is open to soil or moisture for certain period of time get weakened due to action of different types of bacteria, insects and fungi. Three broad categories in which the chemical preservatives are divided are: oil borne preservatives, light organic solvent preservatives (LOSPs) and water borne preservatives. Water borne system has a drawback that this swells the timber, causing increased splitting and twisting.