What Is Creosote and Why Does It Matter?
Creosote builds up inside chimneys from burning wood. Here is what it is, why it matters, and how to manage it.
Reviewed by [TBD], chimney and fireplace professional with 20+ years of field experience.
Short Answer
Creosote is a tar-like substance that forms inside a chimney when wood smoke cools and condenses on the flue walls. It is the main reason chimneys need periodic cleaning.
Why It Matters
Creosote is combustible. As it accumulates — especially third-stage glazed creosote — it becomes harder to remove and increases chimney fire risk. Regular cleaning keeps accumulation manageable.
Stages of Creosote
- First stage: flaky, soot-like deposits — routine sweeping removes this
- Second stage: tar-like, sticky buildup — more effort to remove
- Third stage: hardened, glazed creosote — requires specialized removal
How to Slow It Down
- Burn seasoned (dry) hardwood
- Keep fires hot and bright — avoid smoldering
- Maintain adequate air supply
- Schedule cleaning based on actual creosote level, not just the calendar
Related Services
Related Problems
Ready to Get Started?
Start with a $99 inspection. We check the chimney and fireplace system, show you what we find, and explain your options.