Listed below are chimney and fireplace terms and definitions as well as a diagram of a traditional masonry fireplace and chimney. Anatomy of a Chimney Chimney Crown – Your chimney crown protects your chimney from water damage entering through small cracks. Without a proper chimney crown- or if you have a cracked one, rain water seeps into the bricks and mortar of your chimney structure. Even minute amounts of water can result in brick flaking, mortar deterioration, and unsightly salt deposits on your chimney. Eventually, the bricks and mortar break up enough that the chimney is no longer structurally sound. Flue – A flue is simply a passage for conveying exhaust gases from an appliance to the outdoors. A flue may be a duct, pipe, vent, or chimney. An unlined chimney is technically a flue, even though an unlined chimney is a fire hazard. Flue Lining – For a safe flue, a lining must be used to ensure minimal accumulation of flammable debris. This lining should