What is a Chimney liner

A properly working chimney keeps you warm and cozy while decreasing energy costs. One key element that aids in these benefits is a chimney liner, which is why most new and remodeled older homes include them.

What is a chimney liner, and how do you install and maintain one? This article covers everything you need to know to get the most out of your chimney.

What is a Chimney Liner?

A chimney liner is a secondary barrier inside your chimney that protects the masonry from the corrosive byproducts of combustion. The liner also helps contain any flames and smoke, making it easier and safer to vent the byproducts outdoors.

Liners work with traditional fireplaces or stove inserts, including inserts by popular brands like Jøtul, Vermont Castings, Hearthstone, Lopi, and Morso. They also work with gas fireplaces like those by Jøtul, Mendota, Fireplace Xtrordinair, Vermont Castings, and Kozy Heat.

Types of Chimney Liners

There are three types of chimney liners: clay tile, cast-in-place, and metal. Each has its own benefits.

Clay liners are cylindrical clay sections that stack inside your chimney. They have a long history thanks to their insulation properties and ability to contain most types of smoke. These liners can last up to 50 years.

A drawback is that they are expensive to repair and replace, which is why many owners change the liner to a different type later.

Note that these liners aren't recommended for gas systems.

Cast-in-place liners consist of a concrete-like material that is poured down the sides of the chimney. They have strong insulation properties and limit creosote, soot, and damaging gases that lead to fire danger. These liners are also easy to clean. They work well for all fuel types (wood, gas, and oil) and can withstand higher temperatures than the other liner options.

As for the downsides, these liners are the highest-priced option and have become less popular over time due to the high risk of cracks that lead to costly repairs.

Metal liners are wide and flexible stainless steel for wood, coal and oil, and (aluminum pipes for gas only) . They work well for all fuel types (wood, gas, and oil). These are the most popular liners thanks to their low cost, high durability, and range of sizes, shapes, and angles. Once installed, you may not need to replace the liners during your lifetime, and many have a lifetime warranty. They are also easy and affordable to change out, and installation is relatively inexpensive.

Still, cracks can happen, and creosote and soot can build up and may be difficult to remove if left too long. Regular cleaning and maintenance are needed.

How to Select the Right Chimney Liner

The first step is to select the right material for your type of fireplace. For instance, if you have a gas fireplace, you should avoid a clay liner.

Once you have chosen your liner option, you should make sure you have the right amount of liner to fit the width and height of your chimney. If the liner is too small, it won't be able to properly vent the smoke and fumes from your fireplace or stove. If the liner is too large, it could cause your stove or fireplace to overheat.

How to Install a Chimney Liner

Installation steps will depend on the type of liner you select. Here is a basic run-through of each process.

Clay Liners

Clay liners are cylindrical tiles with grooves on one end that connect together. You will also need one with a hole in it to hold an exhaust pipe. You may also need a metal chimney stand to support the weight of the stacked liners.

Installing involves lowering each tile down the chimney using interconnected poles connected to a small jack. Open the jack inside the tile to hold it firmly. Then lower the pole with the liner into the fireplace to the chimney stand. Then mortar and caulk the top of the chimney to hold the liners in place and prevent water from entering the chimney.

Cast-in-Place Liners

This process involves pouring a concrete-like mixture down the chimney flu and outside a chimney former - an inflated tube with spacers on the outside. Once you have poured the material and it has cured at a set amount of time dictated by the mixture, deflate and remove the interior former.

Metal Liners

Metal chimney liner kits often include the necessary parts and instructions for installation, including an insulation liner, a rain topper, and a junction piece.

The liner piping comes quite long, and you can also connect multiple sections with the male side (crimped side) facing down. Note that some liners work opposite, so consult your pipe maker.

Make sure that the liner is connected correctly and sealed. Without a tight seal, you risk poor flame, leaks, liner damage, and fire danger.

When installing, attach an insulation liner around the outside of the pipe. Then lower the liner down the chimney and mortar the bottom end in place. Cap the top with a rain topper and seal it with silicone to prevent water leakage.

How to Tell if Your Chimney Liner is Broken

There are some tell-tale signs your liner is either broken or not functioning properly. Look for issues like:

• Excessive smoke
• A decrease in the efficiency of your fireplace or wood stove
• Cracks in the mortar joints of your chimney
• Bricks falling apart on the interior or exterior of your chimney

If any of these issues occur, you should do repairs immediately; otherwise, you increase the risk of fire danger and long-term decreased performance.

How to Replace Your Chimney Liner

The replacement process is similar to installing a new liner. Be sure to remove and repair any damaged mortar, bricks, or other materials from the chimney before installation, and give yourself a few days before replacing your liner to ensure any repairs are dry.

How to Maintain Your Chimney Liner

Inspect and clean your liner when doing any other cleaning and maintenance on your chimney. Look for cracks or leaks in the liner and in the connections to your appliance. Start by removing any debris from the fireplace or stove, and look up the chimney from the firebox with a flashlight. If you see any cracks, holes, or other damage, then repair or replace the liner.

For cleaning, use a chimney brush to remove any soot or creosote buildup. Then use an ash vacuum to remove any excess debris. If there's still buildup, use soap and water or a creosote-busting cleaning solution to remove it.

A Chimney Liner: Your Secret to a Strong Performing Fireplace

Chimney liners help you better control and limit issues like creosote and soot to maintain the ideal heat you need. At the same time, they allow for easier maintenance and cleaning than would be needed otherwise. They are designed to make your life easier and safer, as well as warmer, making them well worth the investment.