What is creosote, and why does it matter?
Creosote is the residue left when wood smoke cools on the walls of the flue. It starts as a flaky soot, hardens into a crust, and at its worst becomes a shiny, tar-like glaze. All three forms burn. A chimney fire can crack a clay flue liner and damage the masonry, and a slow one can happen without anyone noticing.
You can slow creosote build-up between sweeps:
- Burn dry, seasoned hardwood, not green or damp wood.
- Burn hotter, shorter fires rather than letting a fire smolder for hours.
- Open the damper fully before you light the fire.
- Never burn trash, cardboard, wrapping paper or a Christmas tree in the fireplace.
None of these stop creosote completely. They just mean less of it for the sweep to remove.
