Wood preservation is the act of treating and impregnating wood by stabilizing dimensions, increasing strength and resistance to water moisture and chemicals and reducing cracking; primarily completed with autoclave under vacuum.
The structure of wood is similar to a sponge, with cell cavities and cell walls, which represent the actual wood. The aim of wood preservation is to coat these walls with preservative to protect from decay caused by wood-destroying fungi and insects. The preservative penetrates deep into the wood with the aid of pressure and vacuum. First, the vacuum removes the air from the cavities to create space for the preservation solution. This solution is forced deep into the wood under high pressure.