The Importance of a Chimney Liner 

Accidental fires originating in a home’s chimney account for the highest percentage of annual house fires reported.  In the unfortunate event of a chimney fire, the flames can burn hot enough to crack bricks and melt mortar.  So if there weren’t already cracks in the chimney’s structure, the intense heat yields a thermal shock creating cracks and displacing mortar.  These cracks grant the flames access to the wooden structure of your home, essentially eliminating the purpose of a chimney.

Many older homes have unlined chimneys or chimneys lined with clay tiles, which do not meet most current building standards since they crack and deteriorate easily.  Modern chimney liners limit the heat transfer from your chimney to the surrounding structure and protect the masonry from damage.  When in use, fireplaces send a plethora of corrosive byproducts through the flue of your chimney.  With time, these destroy the mortar joints and create dangerous cracks.  Liners provide an added shield to your chimney’s internal anatomy and hold up better than masonry products to creosote and other corrosive substances.

While accidental fire prevention is the primary purpose of a liner, chimney liners provide a number of additional benefits!

  1. Protect mortar and brick from deterioration created by condensation from gas fireplaces or evaporating moisture from the burning of unseasoned wood (which contains higher levels of moisture than seasoned wood).
  2. Unlined chimneys result in higher rates of carbon monoxide and other harmful gases leaking into the home’s living spaces rather than properly exiting the flue.
  3. Condensation from wood burning results in tar and creosote buildup. Both of these substances are highly flammable and corrosive.  The liner provides an added shield of protection from both the condensation and corrosive byproducts.
  4. Lined chimneys have higher levels of energy efficiency. Properly lined chimneys enhance airflow and create better heat retention.  Additionally, unlined chimneys require more wood or fuel than lined chimneys.

So, what is a chimney liner?  As mentioned, liners are installed in the chimney’s flue to provide insulation and a protective barrier for the masonry components of your chimney. Liners are fitted to your exact fireplace type and flue size needs.  Today, liners are most commonly made of metal since ceramic versions have a tendency to crack and require more frequent maintenance.  Chimney liners are designed to last a very long time, but should still be regularly inspected and cleaned.  If your chimney doesn’t yet have a liner, chimney professionals can determine the best size and type to keep your chimney safe and structurally sound for many years to come!

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