What is located directly behind the damper of a fireplace?

The area located directly behind the damper of a fireplace is the smoke shelf. The smoke shelf plays a crucial role in the draft of the chimney system. It is a horizontal ledge positioned above the firebox and below the flue. The purpose of the smoke shelf is to catch any smoke and ash that may be pushed back through the damper when there is a strong wind or other unfavorable airflow conditions. This feature helps maintain a proper draft by allowing the smoke to rise into the flue instead of escaping back into the living space.

Additionally, the smoke shelf assists in keeping the chimney clean by directing the flow of smoke upward, minimizing the risk of condensation and creosote buildup that can occur if smoke has no proper channel to escape. The damper and smoke shelf work together to ensure efficiency and safety when using the fireplace, making the smoke shelf an essential component in the design of chimney systems.