Chimney anatomy

01 · Chimney cap

A chimney cap sits on top of the chimney and prevents rain, debris, and animals from entering the flue.

• Can become rusted, leading to water leaks.
• May get dislodged in strong winds.
• Clogged mesh can restrict airflow.

02 · Crown

The chimney crown is a slab that covers the top of the chimney, directing water away from the flue.

• Cracking due to weather exposure.
• Erosion from constant water flow.
• Improperly constructed crowns can hold water.

03 · Flashing

Flashing is a metal barrier that seals the space between the chimney and roof to prevent water from entering.

• Can become loose or detached.
• Corroded flashing allows water leaks.
• Improper installation leads to leaks.

04 · Brick and mortar

The brick and mortar form the structure of the chimney, providing stability and insulation.

• Mortar can crack and crumble over time.
• Bricks can spall from freeze-thaw cycles.
• Water penetration weakens the structure.

05 · Flue liner

A flue liner protects the chimney walls from heat and corrosion, and helps contain the fire within the chimney.

• Can crack or break with age.
• Creosote buildup increases fire risk.
• Improper sizing affects draft efficiency.

06 · Smoke chamber

The smoke chamber is located above the firebox and helps direct smoke and gases from the fire into the chimney flue.

• Can develop cracks from heat.
• Improper construction leads to poor draft.
• Soot accumulation obstructs airflow.

07 · Damper

The damper is a movable plate that controls airflow in and out of the chimney, allowing you to close it when not in use.

• Rust can cause it to stick or jam.
• Improper sealing lets cold air in.
• Warping can prevent complete closure.

08 · Firebox

The firebox is the part of the chimney where the fire burns, typically constructed from fire-resistant materials.

• Bricks can crack under extreme heat.
• Mortar joints may deteriorate.
• Creosote accumulates, increasing fire risk.