Chimney anatomy

01 · Chimney cap

The chimney cap sits at the top of the chimney and prevents rain, animals, and debris from entering.

• Can become damaged or dislodged, allowing rain and pests in
• May rust or corrode, impacting effectiveness
• Clogs with debris, blocking smoke exit

02 · Crown

A chimney crown is a slab that covers and seals the top of the chimney to prevent water damage.

• Cracking due to weather exposure
• Can chip or deteriorate, leading to leaks
• Improper slope leads to water pooling

03 · Flashing

Flashing is metal installed where the chimney meets the roof to prevent leaks.

• Can pull away due to temperature changes
• Rust and corrosion can create gaps
• Improper installation leads to leakage

04 · Brick and mortar

The bricks and mortar form the structure of the chimney and must remain intact to ensure stability.

• Cracking or spalling due to freeze-thaw cycles
• Mortar joints may erode, weakening the structure
• Water intrusion can cause deterioration

05 · Flue liner

The flue liner protects the chimney walls and ensures safe passage of smoke and gases.

• Cracks or gaps can allow toxic gases to escape
• Can become blocked with creosote build-up
• Improper size negatively impacts draft

06 · Smoke chamber

Located above the firebox, it funnels smoke from the fireplace to the flue.

• Uneven surfaces can cause turbulence and reduce efficiency
• Poor construction may lead to smoke leakage
• Creosote build-up can lead to chimney fires

07 · Damper

A damper is a moveable plate that controls airflow and drafts in the chimney.

• Rust can prevent it from opening or closing
• Improper sealing leads to heat loss
• Misalignment can cause operational issues

08 · Firebox

The firebox is where you build and contain the fire in the fireplace.

• Bricks can crack under extreme heat
• Mortar joints may erode over time
• Water damage can weaken the structure