Chimney anatomy

01 · Chimney cap

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

• Rust or corrosion can lead to a faulty cap.
• Improper installation can cause water leaks.
• Clogs from debris can obstruct airflow.

02 · Crown

The crown is a concrete slab that covers the top of the chimney to protect it from weather damage.

• Cracks can form, allowing water to seep in.
• Deterioration from exposure to the elements.
• Poor construction can lead to premature wear.

03 · Flashing

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

• Leaks due to damaged or missing flashing.
• Improper sealing can lead to water damage.
• Corrosion of metal can cause failure.

04 · Brick and mortar

Bricks and mortar form the structural body of the chimney, providing stability and insulation.

• Cracking from freeze-thaw cycles.
• Erosion of mortar joints, leading to instability.
• Spalling bricks due to moisture absorption.

05 · Flue liner

A flue liner is a clay or metal conduit inside the chimney that channels smoke and gases safely out of the house.

• Cracks or breaks from thermal stress.
• Corrosion in metal liners can lead to blockages.
• Improperly sized liners reduce efficiency.

06 · Smoke chamber

The smoke chamber is located directly above the firebox and helps funnel smoke smoothly into the flue.

• Creosote buildup can lead to chimney fires.
• Uneven surfaces impede smoke flow.
• Cracking from repeated heat exposure.

07 · Damper

The damper is a movable plate that controls airflow in and out of the chimney.

• Sticking due to rust or debris.
• Improper sealing can cause heat loss.
• Warping can prevent a proper seal.

08 · Firebox

The firebox is the area where the fire burns, confined by firebrick to handle high temperatures.

• Damaged firebricks can lead to heat damage.
• Cracks in the mortar can allow smoke leakage.
• Soot buildup can reduce efficiency.