Kilning is a method used after air drying to bring timber down to a moisture content suitable for its use. Air dried timber outside in stick would only reach an average moisture content of 18-24% average moisture content after a period of air drying for several years. The average humidity of an internal structure today is 10/12%. Kiln dried timber has to be kilned to this moisture to eliminate movement. Timber that is air dried in stick is put into a kiln chamber. The kiln chamber is heated with water and steam to make the wood more pliable, fans then used for air movement and vents to extract the steam. Kilning is very specialized and not many companies kiln today. Without kilning timber, the timber would move as the final moisture is achieved. Associated Timber owns a state of the art biomass boiler to use all onsite offcuts and waste to kiln dry without fossil fuel.