When Should I Line or Reline My Chimney?
Your Chimney Was Built Without A Flue Liner
A single wall brick chimney can be extremely hazardous. The purpose of a liner is to protect the house from heat transfer to combustibles. An unlined chimney allows enough heat to transfer through and ignite wood structures in just a few hours. Liners also protect the chimney structure from the corrosive byproducts of combustion. If the flue gases penetrate to the brick and mortar the usable life of the chimney decreases. Flue gases are acidic and literally eat away at the mortar joints from inside the chimney. Heat transfers more rapidly to the nearby combustibles and dangerous gases such as carbon monoxide can leak into the living areas of the home. Liners allow for a correctly sized flue, improving the performance and safety of the appliance being vented. An under or over sized liner can allow the production of carbon monoxide which then leaks into the structure.
Your Current Liner is Damged
Your current liner could be damaged due to incorrect sizing, lack of cleaning, thermal shock, chimney fire, or just general deterioration from acidic flue gases. Your flue should be visually inspected at least once per year by an equipped and experienced professional. If there is any reason to suspect cracked or damaged liners this should be confirmed by a NFPA inspection of the entire chimney.
You Are Changing The Appliance
You should consider relining when making the following changes:
To Improve Safety
If your structure was built more than 20 years ago there is a good chance you could improve the safety and efficiency using modern methods. The most common improvements are to fireplaces and furnaces venting through masonry chimneys.
Converting Fuels
When furnace or boiler installations are converted from one fuel to another, relining becomes an important consideration. If you have converted your heating system from oil to gas heat, your chimney could present unknown hazards unless you have had the chimney properly inspected and maintained. After oil to gas conversions the sulphur deposits left from years of oil burning mix with water vapor produced by the new gas appliance. This forms an acid which attacks the bricks and mortar in the chimney. The brick and mortar deterioration can lead to blockages in the venting system that may allow carbon monoxide into the home. This deterioration can occur rapidly and should not the ignored.
A single wall brick chimney can be extremely hazardous. The purpose of a liner is to protect the house from heat transfer to combustibles. An unlined chimney allows enough heat to transfer through and ignite wood structures in just a few hours. Liners also protect the chimney structure from the corrosive byproducts of combustion. If the flue gases penetrate to the brick and mortar the usable life of the chimney decreases. Flue gases are acidic and literally eat away at the mortar joints from inside the chimney. Heat transfers more rapidly to the nearby combustibles and dangerous gases such as carbon monoxide can leak into the living areas of the home. Liners allow for a correctly sized flue, improving the performance and safety of the appliance being vented. An under or over sized liner can allow the production of carbon monoxide which then leaks into the structure.
Your Current Liner is Damged
Your current liner could be damaged due to incorrect sizing, lack of cleaning, thermal shock, chimney fire, or just general deterioration from acidic flue gases. Your flue should be visually inspected at least once per year by an equipped and experienced professional. If there is any reason to suspect cracked or damaged liners this should be confirmed by a NFPA inspection of the entire chimney.
You Are Changing The Appliance
You should consider relining when making the following changes:
- Converting an open fireplace to a woodstove insert, gas fired insert, or gas log set
- Installing a new furnace or water heater
- Switching from oil or coal fired equipment to gas fired equipment
- Adding an additional appliance to a flue already in use
- Relocating appliances further away from the existing chimney
To Improve Safety
If your structure was built more than 20 years ago there is a good chance you could improve the safety and efficiency using modern methods. The most common improvements are to fireplaces and furnaces venting through masonry chimneys.
Converting Fuels
When furnace or boiler installations are converted from one fuel to another, relining becomes an important consideration. If you have converted your heating system from oil to gas heat, your chimney could present unknown hazards unless you have had the chimney properly inspected and maintained. After oil to gas conversions the sulphur deposits left from years of oil burning mix with water vapor produced by the new gas appliance. This forms an acid which attacks the bricks and mortar in the chimney. The brick and mortar deterioration can lead to blockages in the venting system that may allow carbon monoxide into the home. This deterioration can occur rapidly and should not the ignored.