As discussed in a previous blog, there are several types of chimney liners, all of which are used to serve the same purpose.
Over the course of the years, clay liners, cast-in-liners, and more recently, metal chimney liners, have been the silent protectors of our chimneys and homes, playing a part in ventilation, fire safety, gas emission, and structural damage. However, homeowners seldom know the difference between the types of liners and their pros and cons.
History: Clay liners were first introduced and have been standard in chimneys, since the early to mid 1900’s. Clay is pre-shaped or pre-formed into tiles, which are then installed into the inside of the chimney flue, using mortar to adhere them on. These tiles are also often cut to size, in order to fit together and accommodate any curves or angles in the chimney. Clay liners are typically installed during the initial construction of a chimney, not afterwards.
Pros of Clay Liners:
– Can endure and withstand even the highest of temperatures, created by various fuels (wood, gas, etc.) and do not break or become damaged
– Is notorious for being able to withstand corrosive materials
– The tiles, themselves, do not allow gasses to permeate and enter the stack.
– Last an estimated 50 years, if installed properly, and barring any existing cracks or damage
– Energy efficient material
– Require little to no maintenance
– The material is inexpensive and therefore, preferred
Cons of Clay Liners:
– Time-consuming and tedious to install – each tile must be cut, aligned, and mortared into place
– Costly by way of labor, especially post home construction and repairs
– Difficult to repair and requires special tools to chip tiles from the top of the chimney stack, down. In some cases, the wall of the stack must be broken through, in order to repair/replace certain tiles (costly!)
– If tiles are not fitted perfectly, the gaps or spaces, can lead to cracks, water damage, gas leaks, and other damage.
– The uneven surface of mortared tile leads to drafts and poor ventilation, which increases chances of fires and carbon monoxide build-up
– Difficult to install post chimney construction
– Not good for small or oddly shaped chimneys
– Must be installed and/or repaired by a professional