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CHIMNEY INSPECTION DIAGNOSIS REPAIR
BACKDRAFTING HEATING EQUIPMENT
CARBON MONOXIDE - CO
CHIMNEY COMPONENT DEFINITIONS
CHIMNEY FIRE ACTION / PREVENTION
COMBUSTION GASES & PARTICLE HAZARDS
COMBUSTION PRODUCTS & IAQ
FLAME COLOR, BLUE vs YELLOW COMBUSTION
HOME HEATING SAFETY
Moisture / Frost Damaged Chimney
ODORS & SMELLS DIAGNOSIS & CURE
Safety Recalls, Chimneys, Vents, Heaters
STAIN DIAGNOSIS on BUILDING EXTERIORS
WOOD, COAL STOVES & FIREPLACES
WOOD STOVE SAFETY
All about chimney creosote: cause, cure, prevention, chimney creosote & chimney cleaning advice: this article describes the formation of creosote in wood-burning heating appliances such as woodstoves and fireplaces and gives advice on reducing the fire risk. Creosote deposits accumulate in all types of chimneys - masaonry, or metal, where wood burning appliances are vented. Creosote is combustible and if it is set afire the resulting chimney fire is extremely hot. Roaring like a freight train, a chimney fire can melt through even a well-built "safe" chimney, setting the building on fire.
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Creosote odors in buildings: causes & cures
You may smell a chemical odor that is traced to a chimney or fireplace when that system is not in use, typically in the spring and summer and during wet weather. Water entering the chimney from the top (leaks, or a bad or missing cap) or moisture condensation forming inside the flue can dissolve some of the creosote deposits leading to an odor. A downdraft through the chimney brings those odors into the home. Have the chimney inspected and cleaned and close the damper when the chimney is not in use.
See ODORS GASES SMELLS, DIAGNOSIS & CURE for help in tracking down and curing smells or odors in buildings.
How to Prevent Creosote Chimney Fires
How Often Should the Chimney be Cleaned to Remove Creosote
According to NFPA 211,
But depending on the creosote formation factors we described above, your chimney may need cleaning more often in order to be safe.
According to CSIA,
We note that "appreciable buildup" and "capable of damaging the chimney" are too vague to guide a homeowner. The judgment of a chimney professional can assist you in learning to recognize when your chimney needs cleaning.
How Creosote Deposits in Chimneys are Cleaned
Also see Chimney Cleaning Advice, Procedures.
Creosote deposits may be removed by using a stiff chimney brush if the deposits are sooty in character. This is the easiest and best condition to handle.
Creosote deposits that are glazed and hard on the chimney walls can be difficult to remove by may be removable using a powered mechanical brush.
Creosote deposits that are sticky, oozy, "gummy" are very difficult to remove without a chemical treatment - chimney cleaning chemicals are not recommended by the CSIA.
We have observed that a "gummy" creosote deposit may harden when the chimney dries or is (carefully) heated.
Watch out: we have also seen "chimney cleaning sticks" a high-temperature flare that is tossed into a fireplace or woodstove to "burn off" the creosote. In our opinion you're asking for a chimney fire, and we would not rely on such products. Call a professional, certified chimney sweep instead, or ask for advice from your local fire department.
Watch out: creosote itself can affect your health: it is a skin, eye, and respiratory irritant. Depending on the level and location of exposure creosote can also act as a carcinogen.
Frequently Asked Questions (FAQs)
Questions & answers or comments about creosote: the rate of creosote deposition in chimneys, creosote and chimney fires, creosote odors & hazards, and how creosote is cleaned out of chimneys & flues.
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Technical Reviewers & References
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