Performance in fire

Date Published

27 August 2022

Document Type




If timber is protected from direct attack by a fire source, it cannot ignite and burn until the surface temperature reaches at least 400°C. Once ignited, timber burns steadily at a predictable rate and, in the process, charcoal is formed on the surface of the wood which serves to insulate and protect the core. The thermal insulation properties of timber are such that timber just a few millimetres inside the burning outer layer is only warm (in contrast to high thermal conductivity materials such as metals).

Key Information

Timber burns steadily at a predictable rate and charcoal formed on the surface of the wood serves to insulate and protect the core.

Reaction to fire and resistance to fire are the two key areas to consider when looking at the performance of a material when exposed to fire.

Reaction to fire is a measure of how easy it is to ignite that product and also how that material contributes to the fire development and spread.

The reaction to fire performance of timber and wood-based panel products is improved with the use of fire retardant coatings.

Case studies

The new Refectory at Norwich Cathedral, the first stage of development to help sustain the future life of this important church, was completed in 2004 and received the Gold Medal at the 2004 Wood Awards.

The shell is formed of flat polygonal plywood panels, connected at the edges with hinges and faceted to form a dramatic curved shape. The name derives from the panel shapes which mimic the pattern of a giraffe’s colouring.