What Is a Smoke Shelf in a Chimney and How Is It Used?

No need to worry about downdrafts thanks to this ledge

Traditional fireplace in empty room
Photo: Spiderstock / E+ / Getty Images
Traditional fireplace in empty room
Photo: Spiderstock / E+ / Getty Images
Haniya Rae
Written by Haniya Rae
Haniya Rae, Content Writer and Strategist
Updated September 4, 2024

Highlights

  • A smoke shelf is an important part of a chimney that helps prevent strong downdrafts from blowing into your home.

  • A smoke shelf also prevents water and debris from entering your house. 

  • You may be able to clean the smoke shelf yourself, but if it’s hard to reach or you can’t see it, it’s better to call a pro.

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A chimney is made up of several parts that help it work safely and efficiently, keeping dangerous smoke from entering the house. The smoke shelf within your chimney may be simple enough: It’s essentially an outstretched ledge that is both a fire barrier at the throat of your chimney and a draft deterrent for wind entering your chimney. Let’s take a closer look at how this component works and how to maintain it. 

What Is a Smoke Shelf and How Does It Work?

Illustrated diagram of a chimney with 12 parts identified, including the spark arrestor, smoke chamber, flue liner, and appliance connectors

A smoke shelf is a small ledge that slightly juts out within your chimney. The top portion of it either lays flat or curves toward the flue. It’s typically located behind your fireplace as a slightly angled wall and continues above the fireplace, with the actual shelf inside the smoke chamber. Typically, a smoke shelf is made of brick, though some chimneys may use ceramic tile or rubble.

A smoke shelf redirects cold air and catches water and debris. When you have the chimney damper open, cold air comes into the chimney and hits the smoke shelf. It’ll mix with the warm, smoke-filled air from your fireplace, and then help carry the smoke and warm air out of the chimney so that it doesn’t go back into your home. 

It can also catch water if it’s raining or snowing or leaves or other debris if it’s windy outside. This prevents water or debris from unexpectedly hitting your fireplace.

Does My Chimney Need a Smoke Shelf?

Red roof of a detached house and chimney
Photo: intek1 / iStock / Getty Images Plus / Getty Images

If you don’t have a smoke shelf in your chimney, this can cause issues with drafts coming into your home and possibly bringing lots of smoke. The ledge part of the smoke shelf is installed directly behind your fireplace and typically works as both a thermal barrier and a way to direct the smoke through the chimney damper. Without it, you may have a draftier home, and smoke and toxins from the fire may blow inward if there’s a strong downdraft.

What Are Some Signs My Smoke Shelf Is Damaged?

Your smoke shelf may be damaged if you notice your home is draftier than usual. This can be caused by a number of reasons within the smoke chamber itself, including cracks within the masonry, creosote buildup, or damage to the smoke shelf and liner. 

Though a chimney inspection costs about $450 on average, it’s worth it to hire a chimney repair pro near you who can give you peace of mind and make the necessary repairs before any damage happens to your home.

Frequently Asked Questions

You can clean a smoke shelf using either a bendable brush and dustpan or a shop vacuum with an attachment. You need to be very careful when cleaning and allow the dust to settle so that it doesn’t blow soot and dust from the shelf into your home. You should wear protective coverings such as a mask, goggles, and gloves so that you don’t inhale or ingest large amounts of soot.

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Learn more about our contributor
Haniya Rae
Written by Haniya Rae
Haniya Rae, Content Writer and Strategist
Haniya Rae is a freelance writer with more than a decade of experience in home and appliance product reviews and guides. She was previously on staff at Consumer Reports, where she covered home appliances and topics like cleaning, mold remediation, window installation, and sleep health. She also has worked as a home goods editor for U.S. News & World Report’s 360 Reviews and has freelanced for This Old House and Martha Stewart Living.
Haniya Rae is a freelance writer with more than a decade of experience in home and appliance product reviews and guides. She was previously on staff at Consumer Reports, where she covered home appliances and topics like cleaning, mold remediation, window installation, and sleep health. She also has worked as a home goods editor for U.S. News & World Report’s 360 Reviews and has freelanced for This Old House and Martha Stewart Living.
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