This job can be dangerous. Consult or hire a pro to be safe.
Time to complete
3 hours
You may spend most of the time cleaning up soot and debris.
Cost
$500–$1,000
Only buy supplies if you’re comfortable handling this DIY.
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What you'll need:
TOOLS
Screwdriver
Drill
Measuring tape
Putty knife
Caulk gun
Gloves
Safety goggles
Dust mask
Protective clothing
Drop cloths
Shop vacuum
SUPPLIES
Chimney damper kit
Wire chimney brush
High-heat sealant
Drill bits
Screws and anchors
A chimney damper is a small yet powerful feature that makes your abode more energy efficient while protecting it from harmful smoke, gases, and outdoor elements. Learning how to install a chimney damper is a big step toward making your home cozier and safer. Here's what you need to know about this project before you attempt a DIY.
How to Install a Chimney Damper
It’s a smart move to have your chimney swept and inspected before starting this project. Work with a local chimney repair specialist to ensure your chimney is in top condition.
Angi Tip
You must wear protective gear—long pants and sleeves, a dust mask, gloves, and safety goggles—when working in your fireplace because of loose debris and soot inhalation. Remember, your health and safety should always come first.
Photo: Bill Oxford / iStock / Getty Images Plus / Getty Images
Place a drop cloth in front of your firebox and take steps to protect nearby furniture from soot. Next, grab your wire brush and shop vacuum to remove any remaining soot buildup around the old damper and flue to get accurate measurements.
Measure the flue opening width and length to ensure you purchase the right damper size. Buy your damper kit, paying close attention to the product’s measurements.
Assemble the New Damper
Following the manufacturer’s instructions is key to a successful installation. Start by unpacking the kit you purchased and lay out the parts. It will include the damper plate, control mechanism in the form of a rod or chain, and mounting hardware.
Attach the control mechanism to the damper plate—it’s the part allowing you to open and close the damper from the comfort of your living space. Then, ensure all the small parts, like screws, brackets, and any other additional fasteners, are correctly aligned and tightened. Double-check that the damper plate can move without any obstruction before installation.
Install the Chimney Damper
Position the damper plate into the chimney flue, ensuring it fits securely and aligns properly with the opening. Once it's in place, use a screwdriver or drill to bolt the plate to the flue walls. You may need to drill pilot holes first.
As you tighten the fasteners, check that the damper plate remains level and centered. The goal is to ensure the damper can open and close smoothly while maintaining a snug fit. If the plate sticks, adjust its position slightly before tightening the screws completely.
Seal the Damper
Using your caulk gun, apply the high-heat silicone caulk around the damper's edges to create an airtight seal. Use a putty knife to smooth it out nicely. This small yet significant step is essential for preventing drafts and ensuring the damper functions efficiently.
The mechanism that controls the damper should extend to the fireplace opening, making it easily accessible. Move the control rod or pull the chain to ensure the damper plate opens and closes smoothly. You may need to adjust per the manufacturer's instructions if there's any resistance or if the mechanism is not within comfortable reach.
DIY vs. Hiring a Pro
We highly recommend hiring a professional for this project. Installing a damper requires accurate measurements and handling of potentially hazardous materials, and you should always prioritize your and your home’s safety over saving money with a DIY.
Hiring a professional is always the best decision if you need clarification on what a chimney damper is, need more confidence in your DIY abilities, or want to avoid costly mistakes. Pro installers have the expertise to handle all aspects of the job, from cleaning and inspecting your chimney to ensuring the damper works efficiently.
Frequently Asked Questions
The cost to replace a chimney damper ranges from $160 to $520, depending on the type of damper and the complexity of the installation. If you're looking to repair an existing damper, expect to pay around $100 and $225, depending on the extent of the damage and your location. Hiring a professional ensures proper installation or repair, which can help maintain energy efficiency and prevent drafts, making it a worthwhile investment for long-term savings.
If your chimney doesn't have a damper, you are reducing your home's energy efficiency while allowing drafts, debris, and even animals to enter your home. Remember, installing a damper helps regulate airflow, keeping warm air inside during winter and preventing cooled air from escaping in the summer. It also acts as a barrier to keep out moisture and critters.
Deirdre is a seasoned DIYer and home improvement writer. She believes in the transformative powers of deep cleaning and painting to revitalize any space. Her articles have appeared in HomeLight, The Spruce, Realtor, and more.
Deirdre is a seasoned DIYer and home improvement writer. She believes in the transformative powers of deep cleaning and painting to revitalize any space. Her articles have appeared in HomeLight, The Spruce, Realtor, and more.
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