Airflow
The movement of air and combustion gases through an appliance and venting system.
Why it matters →Plain-language reference
The Chimney Terms Contractors Use—Explained
Twenty-one definitions connect each technical term to what it changes for a homeowner, the service it belongs to and the questions worth asking.
A
C
Camera scan
A video examination of interior flue surfaces using a purpose-built inspection camera.
Why it matters →Chimney cap
A component fitted at a flue termination to limit rain, animal and debris entry while allowing exhaust to discharge.
Why it matters →Chimney crown
The sloped top surface that covers chimney masonry and directs water away from its faces.
Why it matters →Clay flue tile
A fired-clay section used to form a traditional masonry chimney liner.
Why it matters →Creosote
Combustible deposits produced by incomplete wood combustion that can accumulate in a venting system.
Why it matters →Chimney flashing
Layered metal components that manage water where a chimney passes through a roof.
Why it matters →D
Draft
The pressure-driven movement that carries combustion products from an appliance through the venting system.
Why it matters →Dryer vent
The exhaust duct carrying moist, lint-bearing air from a clothes dryer to an exterior termination.
Why it matters →E
Efflorescence
A light-colored crystalline deposit left when water moves through masonry and evaporates.
Why it matters →F
Flue
The passage through which combustion products travel to the exterior.
Why it matters →Flue liner
The inner passage or installed system that contains combustion products and protects surrounding construction.
Why it matters →L
Level 1 inspection
An inspection of readily accessible portions for a system with no known change or performance concern.
Why it matters →Level 2 inspection
An inspection that adds accessible areas and typically video scanning where circumstances require broader evaluation.
Why it matters →Lint
Fibers shed from laundry that can accumulate in dryer exhaust components.
Why it matters →R
Repointing
Removal of deteriorated mortar to a suitable depth and replacement with compatible new mortar.
Why it matters →S
Smoke chamber
The transition area above a fireplace firebox that directs gases toward the flue.
Why it matters →Spark arrestor
Screening intended to limit the escape of larger burning particles at a termination.
Why it matters →Spalling
Breaking, flaking or loss of a masonry surface.
Why it matters →Stainless-steel liner
A listed metal lining system installed within a chimney for a compatible appliance and fuel.
Why it matters →T
Termination
The point where a vent or exhaust system discharges outdoors.
Why it matters →