Chimney anatomy
Every part of a chimney, what it does and what goes wrong with it.
PART 01
Chimney cap
A chimney cap sits on the top of the chimney and keeps rain, debris, and animals out.
- Rust can cause it to deteriorate.
- Animal nests can clog it.
- Wind damage can dislodge it.
PART 02
Crown
The crown is the top surface of the chimney, sloped to shed water away from the flue.
- Cracks can lead to water leaks.
- Worn surfaces may allow moisture to seep in.
- Improper installation can cause pooling water.
PART 03
Flashing
Chimney flashing is a seal between the roof and the chimney that prevents water from entering the home.
- Corrosion can cause leaks.
- Improper installation may lead to gaps.
- Old flashing can become detached.
PART 04
Brick and mortar
The masonry of the chimney consists of the bricks and mortar that form its structure.
- Cracks in bricks can let water in.
- Damaged mortar can lead to instability.
- Freeze-thaw cycles can cause spalling.
PART 05
Flue liner
A flue liner protects the chimney walls from heat and corrosive byproducts of combustion.
- Cracks can allow dangerous gases to escape.
- Erosion of the liner reduces its effectiveness.
- Improper sizing can affect draft.
PART 06
Smoke chamber
The smoke chamber funnels smoke from the firebox into the flue, improving draft.
- Cracks can allow smoke to leak.
- Creosote build-up can restrict flow.
- Improper shape can affect efficiency.
PART 07
Damper
A damper controls the flow of air and smoke in and out of the chimney.
- Rust can prevent it from sealing properly.
- Warps may cause it to stick.
- Debris can obstruct its movement.
PART 08
Firebox
The firebox is the chamber where the fire is built and burns.
- Cracks can lead to heat damage.
- Loose bricks reduce efficiency.
- Mortar deterioration can cause gaps.
01 · Chimney cap
A chimney cap sits on the top of the chimney and keeps rain, debris, and animals out.
- Rust can cause it to deteriorate.
- Animal nests can clog it.
- Wind damage can dislodge it.
02 · Crown
The crown is the top surface of the chimney, sloped to shed water away from the flue.
- Cracks can lead to water leaks.
- Worn surfaces may allow moisture to seep in.
- Improper installation can cause pooling water.
03 · Flashing
Chimney flashing is a seal between the roof and the chimney that prevents water from entering the home.
- Corrosion can cause leaks.
- Improper installation may lead to gaps.
- Old flashing can become detached.
04 · Brick and mortar
The masonry of the chimney consists of the bricks and mortar that form its structure.
- Cracks in bricks can let water in.
- Damaged mortar can lead to instability.
- Freeze-thaw cycles can cause spalling.
05 · Flue liner
A flue liner protects the chimney walls from heat and corrosive byproducts of combustion.
- Cracks can allow dangerous gases to escape.
- Erosion of the liner reduces its effectiveness.
- Improper sizing can affect draft.
06 · Smoke chamber
The smoke chamber funnels smoke from the firebox into the flue, improving draft.
- Cracks can allow smoke to leak.
- Creosote build-up can restrict flow.
- Improper shape can affect efficiency.
07 · Damper
A damper controls the flow of air and smoke in and out of the chimney.
- Rust can prevent it from sealing properly.
- Warps may cause it to stick.
- Debris can obstruct its movement.
08 · Firebox
The firebox is the chamber where the fire is built and burns.
- Cracks can lead to heat damage.
- Loose bricks reduce efficiency.
- Mortar deterioration can cause gaps.