What are the parts of a chimney on a house?
Short answer. A chimney on a house is made up of the cap and crown or chase cover on top, the flue liner that carries smoke and gases, the masonry or framed chase around it, the flashing and cricket where it meets the roof, and the smoke chamber, damper and firebox below. The parts up on the roof are the ones that keep water out, and they are where most chimney leaks begin.
From the top down
- Cap. A metal hood with mesh over the flue that keeps out rain and animals and catches sparks.
- Crown. The sloped concrete slab on top of a masonry chimney that sheds water away from the brick.
- Chase cover. On framed chimneys, the sheet metal top over the chase. It should be sloped or crowned so water runs off.
- Flue liner. Clay tile, stainless steel or cast-in-place liner that contains heat and exhaust.
- Stack. Brick, stone, or a wood-framed chase covered in siding.
- Flashing. Step flashing woven into the shingles along the sides, counterflashing set into the mortar over it, and apron flashing across the downhill face.
- Cricket. A small peaked roof on the uphill side of wider chimneys that sends water around it.
- Smoke chamber, damper and firebox. The parts inside the house where the fire burns and the draft is controlled.
Framed chases on Georgia homes
Many newer Georgia houses have a factory-built metal fireplace with a framed chimney chase sided to match the house. The flat galvanized chase cover on top often rusts and holds water, and the joint where siding meets the roof needs proper step flashing and a kick-out at the bottom. These are frequent leak sources that look like roof leaks.
Who maintains what
A chimney sweep or chimney professional handles the flue, liner, damper and firebox. A mason handles brick, mortar and crowns. A roofer handles the flashing and cricket where the chimney meets the roof. See chimney leaks and crickets and roof flashing explained.