What exactly is Heat Treatment? Heat Treatment (HT) is a process whereby lumber is heated in a closed chamber until it reaches a core temperature of 56°C for at least 30 minutes in order to kill pathogens such as insects, fungi, or micro-organisms. It differs from kiln drying in that it specifies a core temperature for a minimum time period, while kiln drying specifies only a certain moisture content.
The difference is significant. Kiln drying can be accomplished without reaching the temperatures required for heat treating, and conversely, heat treating can be achieved (and often is) without drying the lumber. Wood treated with this process is often used for cladding or siding, flooring, furniture and windows. For the control of pests that may be harbored in wood packaging material (i.e. crates and pallets), the ISPM 15 requires heat treatment of wood to 56 °C for 30 minutes to receive the HT stamp. Heat Treatment (HT) is a process whereby lumber is heated in a closed chamber until it reaches a core temperature of 56°C for at least 30 minutes in order to kill pathogens such as insects, fungi, or microorganisms.