About chimney flue liners
The flue liner represents the path which the gasses and fumes produced in the fireplace will rise and exit through the chimney top. The liner is found in the chimney flue and is not required in any chimney. Nowadays, some chimneys are build with a pre-coated protective layer and don’t require a liner.
Clay liners advantages
The clay tiles help protect your home from fires caused by chimneys. Even if clay isn’t the strongest material you can find, it will do its job effectively. Because the interior walls of the chimney will become porous over time, soot and other debris can stick to them, increasing the risk of a fire to occur. Using clay tiles, the debris will not have a sustainable surface to stick to thus reducing the chance of a fire. Clay tiles also have a low resistance when it comes to high temperatures. This way, in the case of a fire, the tiles will break and help extinguish the flames.
Clay liner disadvantages
There are a few downsides when using clay tiles. The first one is related to maintenance. Clay tiles need frequent maintenance because of moisture infiltrating in the chimney. Dampness will also affect the mortar used to stick the tiles to the inner walls of the chimney. Another issue is that clay tiles need replacement every once in a while, because they will surely break in time.