A traditional masonry chimney with two clay chimney pots on top

Chimney Liner FAQ

Answers to all your questions regarding liner installations, liner types and so much more

By: Tom Regis, NFI Certified Master Hearth Professional

Last Updated: January 7, 2026


Chimney liners play a crucial role in protecting your home, improving fireplace performance, and ensuring safe venting for smoke and gases. Yet for many homeowners, chimney liners are one of the most misunderstood parts of the chimney system. Questions about when a liner is needed, what type is best, and how liners affect efficiency and safety are incredibly common.

This guide breaks down the questions homeowners search for most. From liner materials and installation requirements to safety benefits and code compliance, you’ll find clear, expert-backed explanations to help you make confident decisions about your chimney and fireplace.

#1 Are Your Ventis Chimney Liners UL-Tested?

Absolutely! While there are many companies that sell liners, only a handful have gone through the process of being tested and passing the strict UL Listing codes.

Ventis Liners are UL/ULC Listed and meet all UL1777 and ULC-S640 code specifications. These professional-grade liners are guaranteed to last a lifetime.

The warranty is also transferable to the next homeowner. Ventis Liner's UL/ULC status is why we offer them today. These liners have proved to be the very best available.

#2 Why Would You Reline Your Chimney?

Chimney liners are used in most new masonry applications, as well as in remodels.

Two of the most common uses for relining a chimney are to bypass damaged, irreparable, or older chimneys, and to vent a new heating appliance — like a pellet or wood burning stove — through an existing chimney.

Chimneys without a clay liner can be made safer by installing a stainless steel chimney liner.

#3 Are Chimney Liners Better Than Traditional Masonry Chimneys?

Typically, yes. Chimney liners offer three significant advantages. First, they last considerably longer than traditional masonry chimneys. For example, Ventis Liners are backed by a lifetime warranty.

Secondly, chimney liners are typically easier to clean, since smooth-walled liners make it difficult for creosote buildup to adhere to the inside of the chimney.

Finally, chimney liners maintain a hotter core, boosting your operating draft. In other words, less smoke will be pulled back into your home.

wrench icon Pro Tip:

Creosote buildup is very dangerous. It can lead to chimney fires and carbon monoxide poisoning, because it blocks the chimney flues and prevents the safe venting of combustion gases — including odorless carbon monoxide. Make sure you schedule annual professional inspections and chimney service to keep everything in safe working order.

#4 Can I Reline My Chimney Myself?

Yes, you can DIY. If you are a handy individual, and if you allow us to help you along the way, you should have no problem putting a new liner in your chimney.

Woodland Direct has been in the chimney business for over 40 years. We also have the largest team of NFI Certified Master Hearth Professionals in the country. If you have any questions or run into any problems, you can call our NFI certified chimney professionals toll-free at 800-919-1904.

#5 Are Some Liners Easier to Install Than Others?

There are three types of liners: Easy-Flex, Heavy-Flex, and Rigid.

More than 85% of all relines are completed using an Easy-Flex liner because they're lightweight and don't require special lifting tools. Plus, the Ventis Easy-Flex Liner is backed by the same lifetime warranty as the Heavy-Flex and Rigid models for extra peace of mind.

Although Ventis Liners are designed for ease of installation, it's always recommended to have help when installing flexible liners. If you plan on using a Heavy-Flex liner, more than one person is required to assist with the installation.

#6 Are Any Special Tools Required When Installing Your Chimney Liner?

Not usually. The basic installation tools vary depending on which liner is being installed.

For example, liner gloves, an extension nut driver, crimper, caulk gun, pop-rivet gun (for rigid pipe), liner snips, etc.

#7 Why Is the “Heavy-Flex” Liner More Difficult to Install Than the “Easy-Flex” Liner?

The Easy-Flex liner is light enough that one person could lift a 30-foot roll with one hand.

The Heavy-Flex liner is heavier where a 30-foot roll could weigh 100 lbs.

There are two ways to install the Heavy-Flex liner:

  1. Top-Down, through the chimney opening: What makes this difficult is getting the large heavy unit up on the roof. Using a lift could make the process significantly easier.
  2. Bottom-Up, through the fireplace opening: For this method, a chimney mount winch would be rented. The cable would be dropped through the chimney opening down to the inside of the fireplace. The cable would be attached to the liner and the winch would be cranked, pulling the liner up the chimney. This process is more common; however, we would recommend using one of our pulling-nose cones for ease of installation. The pulling-nose cone is tapered in the front to lessen the possibility of the liner getting caught on anything inside the chimney.

#8 How Should I Measure For My Liner Length?

The best way to measure for chimney liner is to measure from the top of the chimney to either the center of your firebox or to the tee or thimble area where your appliance or stove will connect to the chimney.

It is suggested to add an additional foot or two so your liner doesn't run short.

#9 How Do I Measure For My Chimney Liner Diameter?

Measuring for your chimney liner diameter is more important than most people realize. If the liner diameter is too small, it will not draft properly and will lead to a smoky room.

If the liner diameter is too large, the fireplace or heating appliance will lose its efficiency and must of your heat will go up and out of the chimney.

It's crucial to properly measure for your chimney liner to ensure your fireplace operates as safely and efficiently as possible.

There are two ways to accurately size your chimney liner:

  1. Examine your chimney to make sure the recommended liner size will fit inside the flue. If it will not, you may need an equivalent oval or rectangular size to keep the same amount of draft without choking off the flow.
  2. Call one of our experienced chimney experts at 800-919-1904.

#10 Do I Need To Insulate My Chimney Liner?

Definitely. You should insulate your chimney liner for the following reasons:

  • In most states, insulating your chimney liner is required by code.
  • Keeping the chimney warm will greatly enhance its draft ability.
  • Insulated chimneys greatly reduce condensation, which ages metal chimneys and must be drained.
  • A warm, less condensing chimney would create less creosote built-up and/or corrosive material build-up. With less build-up, the chimney is significantly easier to clean, maintain and last a lifetime.

We're Here to Help

Do you have more questions or need help finding a new chimney liner? Contact one of our NFI certified experts at (800) 919-1904 today!

More Resources

Find out how chimney caps and chimney shrouds can help protect your home.

Wondering when to hire a chimney sweep? Here’s why we recommend scheduling chimney service in the spring.

Thinking about switching to a gas fireplace? Read our Gas Fireplace Buying Guide for everything you need to know.


Photo of Thomas Regis Thomas Regis has been a Technical Sales Representative at Woodland Direct for four years. An NFI-Certified expert, Thomas effortlessly directs his clients toward the perfect products, offering essential installation and safety advice. He's tackled projects of all sizes, from backyard fire pits to custom indoor fireplaces. He has even helped Amy Adams, owner of the Tennessee Titans, find a new fireplace for her home! Beyond his professional achievements, Thomas actively participates in community service projects and enjoys spending time on the basketball court. Call him or one of our experts in fire at 800.919.1904.