The Key Functions and the Types of a Chimney Liner

A liner is an essential part of a chimney. It is a conduit, installed inside a chimney. The materials used to build chimney liners are metal, ceramic and clay. A chimney liner contains the combustion products by releasing their effects into the atmosphere outside. This way, heat and corrosion don’t affect the walls of the chimney.


Functions of a chimney liner


A chimney liner serves a range of functions to protect the chimney. Some of those functions are thoroughly discussed below;

  • Protection from heat transfer – Heat transfer can result in a combustion. An unlined chimney may cause heat to quickly move through, because of which the adjoining woodwork can catch fire in a few hours. A chimney liner is obtrusive to the transfer of heat, which reduces the possibility of a chimney fire.
  • Protection from mordant byproducts – Masonry chimneys are vulnerable to corrosive effects of combustion. Allowing the flue gases to perforates the brick walls could result in the depletion of the life of the chimney. The flue gases are caustic and they can chomp the mortar joints inside the chimney.

The corrosive byproducts might cause the mortar joints inside the chimney to erode, with that the heat transfer becomes rapider and might reach adjacent combustibles. Since repairing mortar joints is not easy, you’ll never want them to undergo erosion.

  • Increase appliance efficiency – Appliance efficiency depends on the size of the flue. A liner can ensure the chimney sweeping equipment will work with maximum efficiency. A wood stove or an oil furnace requires the flue to have an optimum size in order for it to render smooth performance.

The chimney draft might supply combustion air to the appliances. If the liner is not sized correctly, then it may lead to an excessive amount of creosote buildup in the wood stove, making the cleaning work difficult for the cleaning appliances.


Types of chimney liner

Chimney liners are categorised in terms of the materials, used to build them. There are three main types of liners; metal, cast-in-place and clay tiles.

  • Metal liners: When metal is used as the building material for chimney liners, the purpose is normally to upgrade and repair an existing chimney. Metal liners are U.L. tested. If they are installed and maintained accurately, they ensure durability and safety.

You might wonder why you need a stainless steel liner. Such liners are suitable for fuels such as wood and oil. Aluminum is an alternative to stainless steel, but a liner made of aluminum is only suitable for gas application fuels.

  • Cast-in-place liners: Cast-in-place liners are made by cement like products – they are lightweight and easily castable. The benefit of installing a cast-in-place liner is the formation of a smooth and insulated aisle through which flue gases can pass. A new chimney doesn’t require a cast-in-place liner; aging chimneys require them to maintain their structural integrity.
  • Clay tiles liners: Chimney liners made of clay tiles are the most common among all types of chimney liners. The biggest advantage of a clay tile liner is cost-effectiveness. Ease of availability and installation are two other advantages. But alongside these advantages, clay tile liners have some demerits as well. The first is clay tile liners cannot quickly soak up and uniformly distribute heat when the temperature suddenly rises during a chimney fire.
  • 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 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 into them. They can tolerate situations harsher than heavy-flex liners.

Fitting a chimney liner

Many homeowners find the task of fitting a liner difficult. That’s because the size of the liner often doesn’t suit the chimney. A liner sized 6-inches doesn’t fit tight chimneys. So the size of the liner must be apt. If you go for DIY, make sure you don’t have acrophobia. To ease the installation, a homeowner may use scaffolding and a cat ladder.

Get rid of unlined chimneys

If you have an unlined chimney, then it’s high time for you to install a liner. By installing it, you can keep the dangers of fire and combustion at bay. Consult a professional chimney sweep or flue liner installer, so he inspects your home and delivers you the best advice.

About the author:

Adrice White is an experienced Chimney sweep in Hadlow, Kent, TN11. He takes an interest in writing articles on smokestack cleaning. He has been in this field for the last 10 years. You can avail more information about Chimney sweep Tunbridge Wells from his recent articles and blog posts.


Erin Emanuel