What is meant by the statement heavy timber is slow burning?

The statement "heavy timber is slow burning" refers to the fire resistance properties of large wooden beams and columns. Due to their mass, heavy timber can withstand fire for a longer period before being consumed, allowing it to char on the surface while maintaining structural integrity. This slow burning characteristic can provide additional time for occupants to evacuate and for firefighters to respond, making heavy timber a safer option in construction compared to lighter materials.