Which of the following is NOT a basic component of a masonry chimney?

The fireplace mantle is not considered a basic component of a masonry chimney. The fundamental parts of a masonry chimney typically include the chimney walls, chimney cap, and flue liner.

Chimney walls provide structural support and are essential for ensuring the safe operation of the chimney by containing the flue gases. The chimney cap protects the chimney from water intrusion and prevents debris from entering the chimney, which could pose safety hazards. The flue liner is crucial for directing the flue gases safely out of the home and protecting the chimney walls from heat and corrosive byproducts of combustion.

In contrast, the fireplace mantle is an architectural feature that serves as a decorative shelf above the fireplace but does not contribute to the functionality or safety of the chimney itself. Thus, it is not classified as an essential component of a masonry chimney system.