How to Clean a Chimney

To know whether a chimney is due for a cleaning, use a flashlight and a poker or metal tool and scrape the creosote residue. If creosote has accumulated to a depth of more than 1/8 inch, the chimney should be cleaned.

Creosote can form in all parts of your chimney, but it is in the chimney’s smoke chamber just above the firebox where the risk of fire is highest. This area can be hard to reach so check first to see if it can be reached with a brush. If you’re unable to
reach it, you may want to hire a certified chimney professional for the cleaning job.

Follow these steps to prepare to clean a chimney:

• Surround the floor around the fireplace with a tarp or drop cloth to keep the room from getting sooty during cleanup.
• Move fireplace accessories out of the way if needed.
• Remove unburnt wood and ash from the firebox section of the fireplace.
• Open the damper and detach it if possible.
• Cover the front of the fireplace with plastic liner and seal completely with duct tape or other heavy-duty tape to prevent dust from filling the room as you brush the flue. (You can skip this step if using the bottom-up method described below.)

Tip: Wear eye protection and a dust mask whenever you’re in proximity to dust and soot. 

Once you’ve prepared the fireplace for cleaning, you’ll have to climb to the roof and remove the rain cap. This is the metal cap affixed to the chimney that prevents rain, snow, leaves and debris out of the chimney and birds and small animals from entering. Before cleaning, determine the height of your flue to know the length you’ll need for your brushes and other tools. 

• Climb up a ladder or get on the roof by other safe means, bringing the fireplace cleaning tools with you.
• Remove the rain cap or animal guard with a screwdriver or power drill and set securely aside. Consider placing the screws in your pocket so they don’t get lost.

Tip:
Call a professional chimney sweep company for the cleaning job if you're concerned about or uncomfortable with climbing your home's roof.

Cleaning of the chimney’s flue can be done from the roof or through the fireplace. You’ll need a wire brush with an attached extension for this task.

• After removing the rain cap or animal guard, reach into the chimney with the wire brush and scrub the inner walls of the flue with an up-and-down motion.
• Chimney brushes come with extensions, so attach more as needed to brush the length of the flue until you reach the smoke shelf at the bottom.
• When finished, reattach the rain cap or animal guard and carefully leave the roof. Don’t forget your tools.

If you’re uncomfortable with heights and have a fireplace big enough to accommodate your upper body, then brush the chimney from the bottom up.

• Reach into the fireplace with the wire brush and up into the flue. Scrub the flue walls with an up-and-down brushing motion.
• Extend the brush as needed until you reach the top.

Cleaning the chimney flue from the fireplace can be messy. Expect soot and residue to fall on you during this cleaning method, so wear safety glasses and a face mask for protection. Also, you cannot seal off the fireplace with a plastic liner using this method, so use tarps to cover as much of the carpeting and furniture as possible. 

Use a dual line method for cleaning a chimney. Two people are needed for this method of how to clean a chimney, one on the roof and one at the fireplace.

• Remove or unscrew the rain cap.
• A person on the roof holds one end of a rope or line that’s attached to a cleaning brush and lowers down the chimney to the fireplace a rope that’s tied to the other end of the brush.
• From the fireplace, the other person takes the lowered rope. Both persons pull the rope up and down so the brush scrubs the flue walls.
• When finished, reattach the rain cap or animal guard and carefully leave the roof.

• Clean the bottom of the flue with a wire brush.
• Sweep up the debris from inside the fireplace (and the smoke shelf, if accessible) with a broom and dustpan.
• Reattach damper as needed.
• Dispose of creosote appropriately according to local requirements.
• Use a shop vacuum to clean the fireplace and any part of the room that's sooty.