Which part of a chimney system is designed to prevent fire from spreading?

The firestop is a crucial component of a chimney system specifically designed to prevent the spread of fire within a building. It accomplishes this by sealing gaps and openings where the chimney passes through floors, walls, or roofs, effectively acting as a barrier against flames and heat. This helps to contain any potential fire within the chimney, reducing the risk that it will spread into adjacent structural materials.

Understanding this function is essential for maintaining fire safety in a home. The firestop not only protects the structural integrity of the building but also enhances the overall safety of the occupants. This distinction sets the firestop apart from other components of a chimney system, which may serve different purposes. For instance, a flue liner is primarily there to protect the walls of the flue from heat and corrosion, while a chimney cap prevents debris from entering the chimney and protects against downdrafts. Therefore, the firestop plays a critical role in fire prevention and safety.