Ash Dump Door - A metal door located in the floor of your firebox which leads to an ash pit.
Ash Pit - A cavity underneath a firebox, used as a receptacle for ashes.
Ash Pit Cleanout Door - A metal door located at the base of the chimney from which you can remove the ashes that have been put in the ash pit.
Damper - Dampers are most often a metal or cast iron plate that closes the fireplace flue when the fireplace is not in use. This is located just above the firebox and most often is opened by a handle inside the firebox that pushes the metal plate up and out of the way. Other types of dampers include rotary dampers which have a You must fully open your damper before building a fire.
Factory Built Fireplace – These are also known as pre-fabricated or zero clearance fireplaces. These fireplaces typically use a stainless steel, lightweight metal flue instead of a brick chimney with a clay tile liner and should be built with sufficient insulation to be installed within close range of walls and woodwork without requiring any masonry foundation.
Firebox - This is where you build the fire.
Flue - The vertical passageway that vents smoke and noxious gases from your home. In a masonry chimney, you may have two or more flues running through one chimney, such as one from a basement fireplace and another from the first floor fireplace, or one from your furnace and another from your fireplace. Masonry
Fireplace – A structure created with brick, stone or cement blocks that uses some sort of binding agent such as mortar to hold the individual components of the fireplace together.
Mortar Cap – Also known as a Crown. The roof of your chimney structure. Functions as a barrier to water.
Smoke Chamber - The smoke chamber is the area in a masonry chimney that starts just above the damper and continues to where the first flue tile is installed. The clay tile flue liner is supported by the smoke chamber. The smoke chambers are is usually corbeled brick or block work, that is wide at the base and narrows down to the opening the flue liner. Most chambers are 3 ft - 4 ft in height, but can be shorter or taller.