Traditionally, masonry chimneys had clay tiles that covered the inside of the chimney. These tiles were designed to seal the chimney structure and direct all heat, gases, and particles up and out of your home.
However, over time, the tiles crack or break due to weathering, heat and freeze cycles, and other factors. Once the break-down starts, your chimney can become dangerous to use and can require a new lining.
There are many solutions to chimney relining. The most popular is using a stainless-steel liner being installed in the chimney space from top to bottom. This flue can also be insulated to increase efficiency and needs to be fitted properly to the chimney using flexible or rigid flue piping.