When Should You Replace Your Chimney’s Liner?

When it comes to fireplace and chimney safety, the chimney liner is one of the most important protective components. It stops carbon monoxide from seeping through porous bricks and mortar into your home. It prevents hot embers in the smoke from slipping through a crack in the flue and igniting combustible materials around the chimney. It also absorbs high temperatures and harsh chemicals produced by the fire that could cause serious structural damage to the chimney or create pathways for a fire.

Since chimney liners are so important, it is no surprise that homeowners have a lot of questions about them. We have put together this list of answers for the most frequently asked questions about when and why you should upgrade your chimney liner.

• How long do chimney liners last?

The answer to this question depends on the type of chimney liner you have. Clay tile liners and cast-in-place liners typically last around 50 years. Stainless steel flue liners generally last for 15 to 20 years (though low quality liners may not even last for five). Good quality stainless steel chimney liners often come with a lifetime warranty. 

• What is the best type of chimney liner?

There are three different types of chimney liners: clay tile chimney liners, cast-in-place liners and stainless steel flue liners. What type of liner is best depends on when and why it is installed.

A clay tile liner is a good choice when you are building a new fireplace because the materials are inexpensive and the liner will have a long life. It is not a good choice for a replacement liner. It is incredibly challenging and expensive to install a new clay tile liner or repair an old one after the chimney has been built.

A stainless steel liner is the best choice if you have a prefabricated fireplace or are installing a fireplace insert. It is easy to install and can be connected directly to your heating appliance. It is also the most likely to meet state and local venting requirements for your new appliance.

A Cast-in-place liner is the best choice if you have a masonry fireplace with a clay tile liner that is failing or if you have a chimney with structural problems. We recommend AHRENS Chiming Lining. The cast-in-place chimney lining is made with an insulated mortar-like mixture that is perfect for filling in deteriorating mortar joints and reinforcing the chimney’s structure.

• How do can I know my chimney liner needs to be replaced?

The best way to know whether or not your chimney liner needs replaced is to have your chimney inspected by a NFI-certified chimney technician. There are 4 reasons why a chimney specialist would recommend a new liner:

1.    The clay tile liner is damaged or deteriorating

A damaged flue liner is a safety risk because gaps and cracks in the liner can allow carbon monoxide and hot embers to escape from the chimney. This increases the risk of carbon monoxide poisoning and a house fire. A deteriorating liner may also be a symptom of greater structural damage that could increase exponentially if nothing is done. Installing a new liner is the simplest and best solution.

2.    The chimney has a condensation problem

If flue temperatures are too low, it can cause condensation in the flue which contributes to corrosion. It is also a symptom of poor airflow which will result in inefficient fires that produce less heat and generate more creosote buildup.

3.    The fireplace has been converted to burn a different fuel or you’ve had a fireplace insert installed

Whether you have converted a traditional wood-burning fireplace into a gas fireplace or had a wood-burning fireplace insert installed, you need to have a new liner installed. Different types of fuel and fireplace inserts have different venting requirements than traditional fireplaces. In most cases, it is necessary to have a metal flue liner installed that connects directly to the new appliance.

4.    The chimney is unsafe

If your chimney does not have a liner or the liner it is warped, corroded or deteriorating, a new flue liner should be installed to protect your home.

If you have any other questions, leave them in the comment section below! If you want to speak to a chimney specialist, give us a call! Our team has received recognition throughout northwest Illinois, northeast Iowa and southwest Wisconsin for our outstanding chimney restorations and wonderful customer service.