Chimney anatomy

01 · Chimney cap

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

• Can become clogged with debris
• May rust or deteriorate over time
• Could be blown off in strong winds

02 · Crown

The crown is a slab covering the top of the chimney, sealing the gap between the flue and the bricks.

• Cracks can develop due to weather exposure
• Can deteriorate, leading to water leaks
• May become uneven, causing poor drainage

03 · Flashing

Flashing is a waterproof barrier installed where the chimney meets the roof to prevent leaks.

• Can pull away from the chimney
• May rust or corrode
• Can develop leaks if improperly installed

04 · Brick and mortar

These form the visible outer structure of a chimney, built for durability and weather resistance.

• Mortar can erode, causing bricks to loosen
• Bricks can crack due to freeze-thaw cycles
• Water damage can lead to spalling

05 · Flue liner

The flue liner is the inner layer of the chimney that carries smoke and gases out of the home.

• Can crack or corrode over time
• May become clogged with creosote
• Improper sizing can lead to poor venting

06 · Smoke chamber

The smoke chamber funnels smoke from the firebox into the flue.

• Creosote and soot buildup can occur
• Cracks can develop in the masonry
• Poor design can lead to inefficient drafting

07 · Damper

A damper is a movable plate that controls airflow and prevents heat loss when the fireplace is not in use.

• Can become stuck open or closed
• May rust or corrode over time
• Can be damaged by heat and moisture

08 · Firebox

The firebox is the area where the fire burns, made to withstand high temperatures.

• Can develop cracks in the masonry
• Mortar joints can erode
• Metal parts can rust or warp