What is the minimum distance the upper edge of a masonry chimney cleanout should be below the lowest inlet opening?

The minimum distance that the upper edge of a masonry chimney cleanout should be below the lowest inlet opening is set to ensure safety and proper operation of the chimney system. This requirement helps prevent backdrafting and the potential entry of combustion gases into living spaces. A distance of 6 inches from the cleanout to the lowest inlet opening minimizes the risk of blockages or obstructions that could affect ventilation and draft.

In addition, maintaining this distance contributes to the proper maintenance of the chimney and allows for effective cleaning without compromising the safety or functionality of the system. This standard aligns with various building codes and safety recommendations, ensuring that chimney structures operate efficiently and do not pose hazards to occupants.