Ash Pit: A small trench located in the base of a fireplace used as a receptacle for ashes.
Anchor: A band of steel that is secured to the bond beam. An anchor is critical in securing a chimney to the rest of the house and will provide support for both in the event of any kind of natural disaster.
Carbon Monoxide: A byproduct of burning wood that is both odorless and colorless. Carbon monoxide is toxic to humans if inhaled in high concentrations.
Chase: An outer barrier or cover for a manufactured
Class-A chimney that is used for aesthetic purposes to hide the chimney from plain view.
Chimney flue: One or more vertical passageways that are used to emit toxic gases from a fireplace, stove, boiler or furnace.
Chimney rain-cap: A cover that is installed on top of a chimney that allows the proper ventilation of gases into the atmosphere but prevents the intrusion of water, leaves, branches, animals or other debris into the chimney flue.
Chimney Fire: A fire that occurs due to the ignition of
stage 3 creosote inside the chimney flue.
Log grate: A raised metal grid where wood is placed in the firebox to prevent the fire from having direct contact with the hearth.
Hearth: The floor of a firebox.
Outer Hearth: The area located directly outside of a
firebox opening. The outer hearth is constructed of
masonry of other non-combustible or heat resistant
materials.
Masonry Chimney: A chimney made of stone, brick,
cement, or other masonry materials that are field
constructed, often times at the same time the house is originally built (the most traditional type of chimney).
Parging: A mixture of mortar that is spread over the inside of a chimney to prevent gas from escaping before exiting through the flue and to repair minor cracks in a chimney.
Pyrolysis: A chemical decomposition of a fuel (usually wood) that is caused by heat, not combustion. Pyrolysis occurs when a piece of wood is placed in a fire but does not have enough oxygen to ignite. The by-product of this process is char.
Smoke Chamber: Area of a chimney above the damper and smoke shelf but before the flue that compresses the gases and smoke from a fire in order to facilitate the proper escape of harmful gases out of the flue.
Smoke Shelf: A flat area located behind the damper that is above the back wall of the firebox. The smoke shelf acts as a collecting place for anything that falls down the chimney and is important in stopping downdrafts.
Throat: Area of a chimney that connects the flue to the firebox. The throat is usually where a damper is placed.
Wythe: A barrier of masonry or bricks that separate one flue from another in a chimney.
