CSIA researchers have characterized building a chimney without a lining as "a little less than criminal".

A flue lining of a chimney is a conduit installed inside the chimney which contains the combustion products, directs them to the outside atmosphere, and protects the chimney walls from heat and corrosion. The installation of a flue lining has been recommended for decades. However, many chimneys do not included a flue lining. According to the CSIA, unlined chimneys can cause adjacent woodwork to catch fire. Each year, thousands of appliances are vented into outdated chimneys, resulting in poor draft, water vapor, and corrosion. These problems do not show up immediately and the homeowner may not be aware that they exist.

Having a properly fitted chimney liner is important. It ensures good draft, no corrosion, and no water vapor problems.

Protect your chimney and your self. Have your chimney inspected and maintained on a regular basis.

An ounce of prevention is worth a pound of cure. -Benjamin Franklin