So are chimney liners required by code? In the majority of American States, and every province in Canada chimney lining is required by building codes and standards, fireplaces require a continuous liner from top to bottom, made of clay chimney tiles, a stainless steel chimney liner, or a cast-in-place liner among others.

In the USA the International Residential Code (IRC) and the International Building Code (IBC) ensure the safe and correct operation of wood-burning fireplace chimneys and their chimney liners, you can see more about what they say by touching the link.

If you are in Canada, you can look for more information about your province at the National Research Council of Canada

Flexible Chimney Liner Kit

This 6 Inch x 25-foot flue liner will navigate down most chimneys and is made of non-corrosive stainless steel that will last, it can be used with wood-burning stoves, wood inserts, and oil furnaces.

Comes complete with a rain cap and components.

As a disclaimer, It’s always important to check first with your local building code enforcement office, and an, if you like a professional chimney sweep or building contractor, can also be a good idea in this way you can be sure that your chimney is in compliance with the codes in your state or province.

If you have a chimney with no liner or maybe you have a liner that is damaged and needs replacing, or it’s possible that you live in an older home that has no terracotta chimney liner at all, if you have any of these situations continue reading so you will know what do next and also see how to make your chimney code compliant again.

Is It Safe To Use An Unlined Chimney?

So it’s important to remember that one of the jobs of a chimney liner is to protect the combustible parts of your home that surround the chimney from the extremely hot temperatures produced during fires or a chimney fire, the liner will also protect your home and family from smoke.

Take a look below to see some of the risks and reasons why it can be unsafe to use a wood-burning fireplace without a chimney liner.

Stainless Steel Chimney Cap

304 gauge stainless steel will not rust and looks great on any chimney, this cap will protect your terracotta chimney lining for years to come.

An unlined chimney is at risk of fires

Some combustible building materials are:

  • Wood frame construction
  • Certain types of insulation
  • Plywood and particle board
  • Wood or vinyl or siding
  • Roofing materials, such as asphalt shingles
  • Interior finish materials, such as drywall or plaster

Without a liner in your chimney, heat can move through the chimney so quickly that the National Bureau of Standards states that any adjacent woodwork could catch fire within three and a half hours.

To reduce the risk of a fire, you need a chimney liner to keep that heat from spreading to the combustible parts of your house, no I know what you are thinking.

“How is it possible that there could be wood or combustable components in my cement block chimney?”

Well, the answer is that some builders can be careless and I see from time to time a piece of exposed wood poking out of the cement in a chimney, and sometimes that wood travels to the interior or exterior of the home, so you can see the dander in this and why a chimney liner is necessary not only from a code standpoint but also a safety standpoint.

Terracotta chimney linerPin

A chimney liner contains flue gases

Another safety reason you need a chimney liner is that it contains the flue gases that are corrosive to your cement and brick chimney because these flue gases are corrosive they will eat away at and weaken your chimney and drastically reduce its life span, which will cause gaps and cracks or also flaking of the inside cement in the chimney causing it to break away and fall.

To protect your chimney, home and health it is important that you have a liner.

An unlined chimney can be unhealthy

As stated above cracks and gaps can open in your chimney allowing smoke and flue gases out of your chimney, the dangerous part of this is when those gaps occur on the interior of your home and smoke begins to escape and possibly allowing carbon monoxide into your home possible causing serious health consequences.

Are unlined chimneys safe?

You may be asking yourself at this point if Is a stainless steel chimney liner is necessary? Well, modern building codes require installing a chimney liner in newly constructed chimneys, but if you live in an older home, your chimney may be unlined.

Most century homes didn’t have a clay tile chimney liner because it was not required back then, and most of those older homes have or had coal fireplaces.

YouTube video
Take a look at this great video that shows an unlined chimney and how it looks.

According to the Chimney Safety Institute of America (CSIA), and the National Bureau of Standards, in a study of masonry chimneys in the 1940s and again in the 1980s and discovered that an unlined chimney was so dangerous that one researcher declared that constructing a chimney without a liner was “a little less than criminal.”

This is why a chimney liner is required by code.

Building a chimney without a liner was “a little less than criminal.”

National Bureau of Standards USA

How do I know if my chimney needs a liner?

There are a few signs that may indicate that a chimney needs a liner:

  1. The age of your chimney: If your chimney is over 30 years old, it may not have a liner, or the liner may be in poor condition so if you have never had it inspected by a chimney sweep.
  2. Damage to the chimney: If you notice cracks, gaps, missing bricks, or other signs of damage to the chimney, it may need a liner.
  3. Smoke and drafts: If you notice drafts coming from the fireplace when it is not in use, this may be a sign that the chimney needs a liner, this negative draft is because a chimney without a liner is generally not proportioned properly.
  4. Cracked or broken bricks: If you notice that the bricks of your chimney are flaking or peeling, it may be a sign of water damage, indicating the need for a liner, some times when you see this it can be an indication of a chimney fire also.
  5. Creosote buildup: If you notice a thick, black buildup of creosote on the inside of your chimney, it may be a sign that the chimney needs a liner, chimneys that don’t have a liner will accumulate much more creosote this can cause a chimney fire.

Is a chimney liner required by law?

So are chimney liners required by code? well In the United States, the safety standards for chimneys are set by the National Fire Protection Association (NFPA) and the International Code Council (ICC). According to these standards, it is not safe to use an unlined wood-burning fireplace chimney in the USA.

In Canada, the safety standards for chimneys are set by the National Building Code of Canada (NBCC) and the Canadian Standards Association (CSA). According to these standards, it is not safe to use an unlined wood-burning fireplace chimney in Canada.

In most areas building codes require that all chimneys be lined, and failure to do so can result in fines or you may not be able to get home insurance., also most chimney sweeps will not clean them because if there is a problem in the future it can come back on them.

Even if it is not required by codes in your area, it is recommended to have a chimney lined to ensure safety, and improve efficiency, if you are unsure if your chimney is lined, it is best to have it inspected by a professional chimney sweep.

What are the different types of chimney liners?

  1. Clay tile chimney liner: These are the traditional type of liner also known as a terracotta chimney liner usually found in most masonry chimneys, and are relatively durable, but can crack or break over time if it is not protected with a rain cap.
  2. Cast-in-place liners: These liners are made of a cement-like material that is poured into the chimney to form a new liner, they can be a good option for chimneys that have severe damage, but they can be more expensive and time-consuming to install.
  3. Insulated flex liner: Flex liners are made of flexible corrugated stainless steel and are typically insulated to help improve the efficiency of the chimney, these are easy to install, and often used to reline chimneys with an irregular shape.
  4. Rigid stainless steel liner: Rigid liner is considered to be the most durable option to other types of liners, such as a terracotta chimney liner or flex liner, the stainless steel material is resistant to corrosion and can withstand high temperatures, making it a popular choice for use in wood burning fireplace chimneys, it is also easier to clean than most other options

Are chimney liners required by code? conclusion

My final thoughts on a chimney sweep are that every unlined chimney, should be lined because of all of the benefits and safety reasons mentioned in this post, so take a look at your chimney to make sure it is lined especially if your home is 30 years old.

If you own a century home I definitely recommend you check and see if you have a chimney liner, and if not you know what you need to do if you want to continue using it.

If you found this post to be interesting and informative please leave a comment or share it with friends and family, thank you for reading.

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