Unlike what is commonly thought, wood is a material which has very good fire-resistant properties, if it has sufficient thickness.

• Wood burns at a rate of 0.7 mm per minute (this is 4.20 cm per hour).
• Wood does not lose its mechanical characteristics under the effect of temperature.
• Any sections which are not burned after one hour continue to hold up to the loads imposed.
• In practical terms, one-hour fire stability of a wood beam does not require reinforcement of the section, and thus does not re
  present added cost.
• Further, wood is one of the most ecologically perfect materials. 

As for steel: steel clearly does not burn, however it quickly loses its mechanical characteristics under increasing temperatures.

• As of 650 °C steel beams warp, leading to building collapse.
• The temperature of 650°C can be reached in just a few minutes.
• Steel structures are thus not considered fire stable.