What is the primary hazard associated with chimney fires?

The primary hazard associated with chimney fires is the risk of structural fire due to creosote buildup. As creosote—which is a byproduct of burning wood—accumulates inside the chimney over time, it becomes highly flammable. When chimney temperatures rise significantly, this buildup can ignite, leading to a dangerous fire that can spread from the chimney to the surrounding structure. This fire poses a serious threat not only to the chimney itself but also to the entire building, as flames can extend beyond the chimney, potentially igniting other flammable materials within the structure.

While excess smoke causing visibility issues is a concern during a chimney fire, it is not the primary hazard. Additionally, water damage from fire suppression efforts may occur but is a secondary concern in terms of immediate fire risk. Flashover potential in the flue is related to the intensity of the fire and may occur under certain circumstances, but it is the creosote buildup and the associated risk of a structural fire that are the most pressing issues in chimney fires.