Chimney sweeping and inspection: how often, what's checked and what it costs

The US Fire Administration's advice is to have heating equipment and chimneys cleaned and inspected each year by a professional.² The EPA's is to have your chimney cleaned every year by a certified chimney sweep and your wood-burning appliance inspected and serviced every year by a certified technician.³

Once a year is the least. MU Extension says a cleaning schedule can run from once every couple of weeks to no less than once a year, depending on how much you use the stove, the kind of wood you burn, the kind of stove or fireplace you have and how you run it.¹ Its guide to running a wood stove says to inspect the stovepipe and chimney flue each year before you use the stove, and often during the heating season for creosote buildup. With an air-tight stove, it says to check the stovepipe at least once a month.⁴

Creosote and chimney fires. Creosote is the main reason for cleaning a chimney. A chimney fire can reach 2,000 degrees Fahrenheit, which can warp a metal chimney or crack the tile liner of a masonry one. Cracks or holes left in the flue can let sparks from an ordinary fire through into the attic or the framing around the chimney. MU Extension calls chimney fires a major cause of house fires from burning wood.¹ The EPA says nearly 7 percent of home fires are caused by creosote buildup in the chimney.³

Blockages. Bird nests, fallen bricks and other objects turn up in chimneys. Anything that gets in the way of the exhaust gases can make a fire smoky, and MU Extension says a good cleaning is the answer.⁵

Cracks. The EPA passes on fire officials' advice to have a wood-burning appliance, its chimney and vent professionally inspected each year, including a look for chimney cracks, which can let smoke into the house or expose the chimney's parts to heat that may start a fire.⁶

MU Extension's list for the yearly check is cracked flue liners, broken or missing bricks, heavy creosote deposits, bird nests and anything else that's fallen in. The flue and the stovepipe are cleaned of soot and other residue, and the chimney is repaired or the stovepipe replaced where they need it, so a problem doesn't turn up later in the season.⁴

A few more parts get cleaned as well. The smoke pipes of wood-burning furnaces and stoves need cleaning too, and on a fireplace the cleanup includes sweeping out what's collected on the smoke shelf above the damper.¹ MU Extension's chimney guide calls for a tight-fitting clean-out door at the base of a chimney to help with cleaning.⁵

Where the inspection finds damage, the repair is masonry or liner work, priced on its own. Chimney and fireplace repair costs covers the warning signs a mason looks for and what those jobs cost.

• You smell smoke in the house. The EPA says something is wrong: shut down the appliance and have a certified chimney sweep inspect it.³ A wood stove or fireplace that's installed and used properly should make very little smoke, and if you regularly see or smell smoke, you may have a problem.⁷
• Fires keep smoking. A blocked chimney is one cause, and so is burning green or wet wood or too cool a fire, which keeps the chimney from warming up and drawing fully.⁵
• You've had a chimney fire. Signs of one are a very intense fire, a roaring noise, and flames and sparks shooting from the top of the chimney. Any chimney, metal or masonry, can be weakened or bent out of shape by one, so MU Extension says to have the whole chimney inspected afterwards and any repairs made before you light the stove again.⁴
• You have a newer, more efficient stove. These send less heat up the chimney, so the flue runs cooler, and creosote condenses more easily on a cooler surface.¹ Run the wrong way, they can build up creosote, and they may need more inspections and clean-outs.⁴

MU Extension names three main causes of creosote buildup: wet wood, incomplete burning and cool surfaces. Its advice is a briskly burning fire with dry wood, keeping the flue above 250 degrees Fahrenheit so creosote doesn't condense.⁴ For a high-efficiency stove, it suggests an intense fire for at least half an hour every day with the damper open, to burn off what has built up in small amounts.¹

The EPA's advice on firewood and fires:⁷

• Burn only dry, split, well-seasoned wood. Seasoned wood is darker, weighs less and sounds hollow when knocked against another piece.
• Season wood for at least six months, stored outdoors, off the ground, with only the top covered. Covering the sides traps moisture in.
• Aim for a moisture content under 20 percent, and test the wood with a moisture meter before you burn it.
• Build hot fires. For most stoves and fireplaces, a smoldering fire isn't safe or efficient.
• Don't burn wet or green wood. Don't burn household trash, cardboard, plastic, coated, painted or pressure-treated wood, plywood, particle board, driftwood from the ocean, or wood that's rotted or moldy. These can give off harmful chemicals and may damage the stove or fireplace.

Wood isn't the only fuel that needs its flue looked after. Carbon monoxide comes from fuels that don't burn completely, oil, propane and natural gas among them, and you can't see or smell it. Furnaces, water heaters and room heaters that malfunction are among the products the Consumer Product Safety Commission names as sources. Its advice is to have the heating system professionally inspected and serviced every year, with the inspector also checking chimneys and flues for blockages, corrosion, partial and complete disconnections, and loose connections. During renovations, make sure appliance vents and chimneys aren't blocked by tarps or debris. It also says to put battery-operated carbon monoxide alarms, or alarms with battery backup, on every level of the home and outside sleeping areas.⁸

You can clean a chimney yourself or hire a chimney sweep. MU Extension says it's hard work: pulling a brush up and down the chimney can strain your back and other muscles. A chimney that isn't structurally sound can fall apart when a ladder or your weight leans against it.¹ The EPA suggests checking the credentials of whoever installs or maintains a wood-burning system.⁶

States treat sweeping differently. Utah's contractor rules list chimney sweeping, other than repairing masonry, among the activities that don't need a contractor license.⁹ In Washington, the Masonry specialty in the contractor registration classifications also includes chimney cleaning and repair.¹⁰ Your state's rules page on this site has its rules for chimney and masonry work, with their sources.

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How to check a masonry contractor covers what to look up before you hire.

These are published national ranges from cost guides. They aren't quotes. Each one is where two or more cost guides' ranges agree, credited to each guide it rests on. Use them to check a price, then ask chimney companies near you to quote the job.

Ask whether a quote is for sweeping, an inspection or both, and whether it includes the stovepipe. Any repair the inspection turns up is a separate price.

• Whether the price covers sweeping, an inspection or both, and which flues, stovepipes and smoke pipes.
• What they found, written down, with photos of the flue and the top of the chimney where they can take them.
• Whether the liner is cracked, and whether anything they found needs a mason.
• For a gas or oil furnace's flue, whether they'll check it for blockages, corrosion and loose connections.
• How they'll keep soot out of the room.
• The price in writing before work starts.

If you'd like prices from companies near you, you can send a request through the request form.