Firehardened

Firehardened is a term used to describe wood that has been subjected to fire, either intentionally or unintentionally. This process can significantly alter the properties of the wood. When wood is exposed to flames, the outer layers char and carbonize. This char layer acts as a protective barrier, making the underlying wood more resistant to subsequent burning. The charring process essentially creates a less combustible surface.

The degree to which wood is firehardened depends on several factors, including the type of wood, the intensity and duration of the fire, and the presence of moisture. Some traditional building techniques have utilized firehardening to enhance the durability of wooden structures against fire. For example, historical methods of treating timber for homes and fortifications sometimes involved controlled charring. This technique is distinct from simply burning wood, as the goal is to create a protective layer rather than to consume the material. While firehardening can increase resistance to ignition and slow the spread of flames, it does not make wood fireproof. The internal structure of the wood can still be damaged by prolonged exposure to high temperatures or by direct flame impingement.