This job can be dangerous. Consult or hire a pro to be safe.
Time to complete
4 hours
Cost
$500–$1,000
Only buy supplies if you’re comfortable with advanced-level DIY.
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What you'll need:
TOOLS
Ladder
Tape measure
Flashlight
Flathead screwdriver
Wrench
Tin snips
Caulk gun
Hack saw or reciprocating saw (optional)
SUPPLIES
Stainless steel chimney liner kit
Weather-resistant caulk
Every safe chimney needs a liner, which channels the byproducts from a fire to the outdoors. This protects the chimney's structure from damage and increases fireplace efficiency. If your chimney doesn't have a liner or needs a replacement, you'll want to install a new one before you use your chimney. This guide walks you through the steps for how to install a chimney liner.
Measuring for the Correct Chimney Liner Size
Measure the height of your chimney from top to bottom and the diameter of the exhaust hole on your fireplace or appliance. Use these measurements to purchase a chimney liner of the correct length and width. Add 12 inches to your length measurement to allow room for error. If you have a wood stove or insert, you can consult with the manufacturer or owner's manual for sizing.
With your measurements in hand, you can purchase a liner kit. Chimney liners can be made of clay or ceramic, but a flexible stainless steel liner is the easiest option for a DIY installation. These liners come in a kit that contains the necessary connection components, top plate, and rain cap. These kits can be customized to fit any chimney.
How to Install a Chimney Liner
Chimney liner installation is fairly complex and will involve the help of at least one other person. Be sure to carefully follow any manufacturer instructions that come with your chimney liner kit as you work through the steps below.
Prep the Liner on the Ground
Open up your liner kit and uncoil the liner itself on a level surface such as your lawn. Attach the bottom of the liner to the bottom vertical connector piece found in your kit and fasten them together with a hose clamp using your wrench or screwdriver.
Insulate the Liner
Chimney liner kits come either pre-insulated or with separate insulation that you attach yourself. If your liner is pre-insulated, skip this step and proceed to step three.
Measure and cut insulation: If there is at least a two-inch gap between the liner and the chimney walls, wrap the liner with an insulation blanket. Cut the blanket to width by measuring the circumference of the bottom termination of the liner. Multiply that measurement by 3.14, then add one inch of overage.
Attach insulation: Lay the blanket flat with the foiling side facing down. Center the liner on it, then wrap the insulation around, overlapping by at least an inch. As you wrap each segment of the blanket, affix it with spray adhesive and seal the seam with foil tape. Repeat until the entire liner is covered.
Wrap with wire mesh: Finally, roll out the wire mesh that came with your kit and wrap it around the entire liner. Clamp the mesh to the bottom connector with a hose clamp, pull it taut, and use another hose clamp to secure it to the top of the liner. Cut any excess mesh with tin snips.
Get in Position
Photo: tinadefortunata / Adobe Stock
To install a chimney liner, one person will need to lower the liner from the roof while the other partner guides it from inside at the bottom of the flue. The specific method to do so will vary depending on your kit, so always review the manufacturer’s instructions and follow them as closely as possible.
In general, however, you'll want to attach the included rope to either a pulling cone or bottom connector, then get on the roof. Have your partner feed the liner up to you from the ground. Once you have the liner on the roof, your partner should go inside and stand near the bottom of the chimney. Throw the rope down to them.
Guide the Liner Down the Chimney
Position the end of the liner with the attached bottom connector over the rooftop opening of the chimney. Slowly begin to guide it down while your partner helps using the rope. Do your best to avoid snags, and gently twist the liner if it gets caught on the chimney walls.
Lower the liner until it reaches the thimble or hole on the side of the chimney in your living space where it will attach. Call down to your partner to hold the connector in place.
Install the Top Plate
Photo: majorosl / E+ / Getty Images
The top plate will seal the flue to prevent rain and pests from entering your home through the chimney. Slide the top plate down the liner until it's sitting on the top edge of the chimney flue. Different kits will have different requirements, so follow your manufacturer's instructions. One method for sealing the flue is sealing the plate with weather-resistant caulk.
Find the locking bolts on each side of the top plate and use your screwdriver to secure the top plate to the flue. Don’t tighten too much or the flue may crack.
Trim Excess Liner Material
Use your tin snips, hacksaw, or reciprocating saw to cut excess liner material at the top, leaving four inches of length above the chimney crown.
Attach the Liner to the Top Plate
With the top plate secured to the flue, you'll also need to secure it to the liner so it can properly bear the liner's weight. Tighten the hose clamp on the inside collar of the top plate using the screw on the outside of the collar.
Connect the Liner to Your Fireplace or Appliance
Climb down from the roof and head inside. Attach the connector on the bottom of the liner to the other connector piece from your kit using any provided clamps. You may need to cut a hole in the mesh and insulation layer to make the connection. This assembly should then connect directly to your fireplace or wood-burning appliance.
Your last step will bring you back to the roof. Insert the collar of the top plate inside the rain cap to secure the two together. There will likely be a hose clamp at the bottom of the rain cap. Tighten the clamp with your screwdriver to complete your installation.
DIY vs. Hiring a Pro
While the steps for installing a chimney liner may seem simple, this is a labor-intensive job that will likely take you up to four hours. It requires climbing onto your roof to work, which we do not recommend due to the fall risk involved. Likewise, minor mistakes can lead to chimney damage that is often difficult and expensive to repair.
A chimney liner is held in place by a top plate and attached top clamp, both of which should be included in most chimney liner kits. The top plate seals to the top of the chimney flue and attaches directly to the liner. This not only holds the liner in place but supports its weight in the chimney.
It takes anywhere from two to four hours to install a chimney liner on average. Your installation time will vary depending on the type of liner you choose to install and the size of your chimney. Installation may also take longer if your chimney needs any prior repairs. Have a local chimney service inspect your chimney for damage before installation.
Nick has been a copywriter in the home services industry since 2017, marketing for hundreds of flooring and home improvement providers throughout North America.
Nick has been a copywriter in the home services industry since 2017, marketing for hundreds of flooring and home improvement providers throughout North America.
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