A Typical Masonry Chimney

Refer to the diagram on this page to learn about the different parts of a typical masonry chimney. Knowing the chimney parts will help you understand chimney inspection and repair services better.

• Cap: Metal, stone, or clay structure intended to keep out rain, snow, leaves, animals, etc.
• Crown: Tapered concrete or mortar. Aids in keeping water off the top of the chimney structure. Without this, freeze-thaw damage can occur.
• Chimney Flue: Clay, ceramic, or metal conduit in a chimney intended to contain the combustion products and protect the chimney shell from heat and corrosion.
• Smoke Chamber: Acts like a funnel to compress the smoke and gases from the fire so that they will squeeze into the chimney flue above.
• Smoke Shelf: The smoke shelf is located behind the damper.
• Mantel: A decorative surround around the fireplace opening.
• Damper: Regulates the draft and air passing from the firebox into the smoke chamber. Top sealing dampers are located at the top of the chimney under the rain cap or by themselves.
• Throat: The rectangular opening just before the damper.
• Facing: The area above the lintel, also called the chimney breast.
• Lintel: The supporting member of the fireplace opening. The lintel is made of angle iron.
• Firebox: The area where the fire is burned, generally built of firebrick. This area can be made of metal, as in a “Steel Fireplace Unit.”
• Hearth: Composed of the firebox floor and the hearth extension (the part of the fireplace that extends out past the fireplace opening).
• Ash Pit: A non-combustible storage area into which the ashes are dumped.
• Foundation: Foundation should be adequate to support the load without settling.