The Official Recommendation
The National Fire Protection Association (NFPA 211) recommends that chimneys, fireplaces, and vents be inspected at least once per year. Cleaning should be performed as needed based on the inspection findings.
The Chimney Safety Institute of America (CSIA) echoes this: annual inspection with cleaning when creosote buildup reaches 1/8 inch or more.
Factors That Increase Cleaning Frequency
You may need cleaning more than once per year if:
You burn wood more than 2–3 times per week during winter You use unseasoned or softwood (pine, spruce) — these produce more creosote You notice a strong smoky smell from the fireplace when not in use You had a previous chimney fire (creosote can reform faster on damaged surfaces) Your chimney has a narrow flue or poor draft
Heavy wood burners in Chicago should consider cleaning in both spring (after winter use) and fall (before the next season).
What About Gas Fireplaces?
Yes, gas fireplaces need annual inspection too. While gas produces less creosote than wood, it still creates combustion byproducts that can corrode flue liners. Gas fireplaces also attract birds, insects, and debris that can block the vent.
An annual inspection catches these issues before they become safety hazards.
What Happens If You Skip Chimney Cleaning?
Creosote buildup increases — creosote is the #1 cause of chimney fires Blockages from debris, animal nests, or leaves restrict airflow Carbon monoxide can back up into your home through cracks or blockages Small problems (minor cracks, loose mortar) go undetected and worsen Insurance claims may be denied if you can't prove regular maintenance
The CSIA reports over 25,000 chimney fires annually in the U.S. The vast majority are preventable with regular cleaning.
Need Professional Help?
Widen Chicago provides honest diagnostics, transparent pricing, and expert service for every chimney and vent job. Same-week scheduling available.