What Material is Used for a Chimney Liner?

This article discusses what material is used for a chimney liner. Installing a chimney liner is the easiest way to make your chimney safer and in most cases improve the functionality of the heating appliance. Installing a high-grade chimney liner should be at the top of the priority list to ensure a safe and long-lasting installation. There are different grades and styles of chimney liners to choose from. Let us learn more about this below.

What material is used for a chimney liner? Chimney liners protect homes from heat moved to combustible materials during fireplace usage. Liners also guard chimney masonry against corrosive byproducts of combustion that can decrease chimney life and impend home occupant safety. These linings can be made of stainless steel, casted masonry material, clay tiles, or aluminum.

Without a chimney liner to protect the inside walls of the chimney, byproducts can degrade the masonry and mortar allowing toxic gases including deadly carbon monoxide into your home. Also, cracks in the flue can allow excess heat to escape through the interior walls and spark a fire. A chimney liner is one of the best ways to protect your home and family.

What material is used for a chimney liner
Photo by Uwe Conrad on Unsplash

What is Chimney Lining?

The liner is the channel that all smoke and gases pass through to exit your home. The chimney liner is inside the chimney and should be a separate component of the chimney construction. The inside of your chimney needs to be covered with a non-combustible lining that can vent the toxic hot gases and particles produced by your fireplace, stove, or furnace. These linings can be made of stainless steel, casted masonry material, clay tiles, or aluminum. The flue or the channel that the chimney is vented through must be free of any cracks, holes, or deterioration to keep your system running safely and efficiently. Any breaches in the integrity of the lining can allow combustible materials that travel up the flue to enter into attics, ceilings, or walls adjacent to the chimney.

Common Materials Used for Chimney Liners

The three primary types of chimney liners used are clay tile, cast-in-place, and metal flue liners. Which one you choose largely depends on how old your home is and when you had the liner repaired or replaced last.

Clay Tile Liners

These are the most common types of chimney liners for older homes as they were inexpensive and could last for approximately fifty years. The downside to these liners is that they can crack when exposed to uneven heating and can be difficult to repair.

Because the tiles are susceptible to cracking when rapidly exposed to uneven heating, they must be adequately maintained and inspected before use. Once the tile has cracked, it creates a vulnerability that could lead to a house fire. Repairing clay tile liners or replacing them with new clay tile can be difficult, and many homeowners switch to a different liner when a repair is needed.

Cast-in Place Liners

These liners are permanent as they are poured in and left in place to harden. The solid liner offers insulation and adds more structural safety to a chimney without cracks or leaks. These liners can also withstand higher temperatures.

It’s important to keep in mind that a cast-in-place liner is a permanent liner. If some damage happens to the liner, it can be necessary to replace the entire liner. While this circumstance is unlikely due to the integrity of the material, it’s worth discussing the pros and cons with a professional when deciding on which liner to choose.

Metal Flue Liner

Metal flue liners are the most popular option for chimney liners nowadays as the installation process is easier and less expensive than other options. Most metal flue liners are made from stainless steel and they are resistant to the corrosion that occurs from combustion. Most people will choose the metal flue liner for their chimney, but that doesn’t mean that you have to when you need yours replaced.

One of the biggest benefits of metal flue liners is that they can be made for essentially any chimney. While cast-in-place liners, for example, can’t be poured in certain chimney designs, metal flue liners can be rigid or flexible, allowing them to be installed in essentially any modern home. The installation process itself is also easier and less costly.

What Are the Other Types of Chimney Liners?

The other types of chimney liners are easy to flex liners, heavy flex liners, and rigid liners. Find out more about these types of liners below.

Easy Flex Liners

This liner type is found in most relined chimneys. It is lightweight and easy to install. The lifetime warranty of easy flex liners is the same as heavy flex and rigid liners. Easy flex liners are UL-Listed and come in different sizes and shapes.

Heavy Flex Liners

Such liners are designed to tolerate extremely harsh situations due to the burning of solid fuel such as wood or coal. Sweeps can clean these liners with the toughest wire brush. Heavy flex liners are recommended for straight chimneys.

Rigid Liners

Such liners are durable and their inside walls are pretty smooth. It’s difficult for creosote to infiltrate them. They can tolerate situations harsher than heavy-flex liners.

What is Aluminum Chimney Liner?

Aluminum chimney liners are not as versatile as their stainless steel counterparts. Aluminum has a melting temperature of 1215 degrees Fahrenheit. Aluminum chimney liners should only be used for lower efficient gas appliances. Generally, just a water heater and older natural gas appliances are approved to be used with an aluminum liner. If your appliance is rated below 83% efficiency rating, you can typically use an aluminum chimney liner. Aluminum chimney liners do cost less than a stainless steel chimney liner, however, the average lifespan of an aluminum liner is going to be around 10 to 15 years. You must never use an aluminum liner for a wood-burning appliance.

What is Stainless Steel Chimney Liner?

Stainless steel chimney liners have a constant running temperature of 1000 degrees Fahrenheit. A stainless steel chimney liner also handles an impressive maximum heat temperature of 2100 degrees Fahrenheit. Most stainless steel liners include a warranty and the higher grade stainless steel liners will last a lifetime. Stainless steel liners are available in three grades of stainless steel: 304L, 316L, and 316Ti.

✅ Video – Installing a Stainless Steel Chimney Liner

SB shared the video below on YouTube. It discusses how to install a stainless steel chimney liner. Stainless steel is a good option for a chimney liner. Click the play button below for the process of how it is done.

What Type of Chimney Liner is Best for My Chimney?

The huge array of chimney systems that could have been built into your home all varies due to factors such as size and what year the build was constructed. Therefore, you should always consult a specialist chimney company for their advice before purchasing. They’ll be able to let you know what type of chimney material is used in your chimney and what liner would work best with the fuel type of your fireplace and the level of condensation that exists inside the chimney flue.

Why Do You Need to Reline Your Chimney?

The main reason for chimney relining is improper liner sizing. Improperly sized lining can lead to soot and creosote deposits and improper draft, both of which are safety hazards. Proper chimney lining size is a difficult variable to determine, so if you have any questions about the best size chimney lining for your home, contact a chimney professional.

The second-largest cause of chimney relining is cracks and breaches in the lining itself, which is a large fire hazard. At the first sign of cracks or damage, call in a professional to ensure your home is safe. Remember, even if you stop using your fireplace, other appliances may vent into your chimney exposing you to potential danger.

Is a Sealant Needed for Chimney Liners?

After years of use, your chimney liner may develop areas of wear and tear, or chips and cracks may occur. If you notice any issues with your liner, a sealant may help bring your liner back to life. The sealant can be used to patch small cracks in your liner. If there is damage to a larger area and a complete coating is needed, a sealant can be a quick fix.

When replacing a liner, a sealant can be used on the chimney’s interior before sliding in the new liner. The inside of the liner can then be coated with a sealant for extra protection. The sealant will help vent flue gases and keep your chimney clean and functional for years to come. Check your sealant to ensure it can be used with your fuel type.


In this article, we have discussed what material is used for a chimney liner. Chimney liners are almost essential in keeping your chimney and heating system in proper health. They come in three main varieties; clay, cast-in-form, and metal. The price of liners will vary on the type and the condition of your chimney. Although each type of liner has its benefits, metal liners are the popular choice. Make sure to keep your liner properly maintained and cleaned. Adding insulation will help to keep your liner and chimney in good condition, extending their life. Thank you for reading!

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