The time comes in the life of every chimney when it needs to have a new liner installed. Yet few homeowners understand the importance of this vital component--let along the differences between commonly available types of liner. If a professional repair person has recently told you that your chimney needs a new liner, and you would like to learn more, read on. This article will explain the differences between two common varieties of chimney liner.
Clay Tile Liners
Clay tile liners are the least expensive and the oldest of the two methods discussed here. That means they are commonly found in homes dating back to the early 1900s. Clay's natural properties allow it to withstand even very high temperatures without cracking, crumbling, or otherwise becoming structurally compromised. Likewise, clay is highly impervious to the corrosive elements present in the smoke passing through your chimney.
Clay tile liners come in preformed sections, which are then joined together by a trained professional. This is fairly easy to do when a home is being built--but when it comes to making repairs, or replacing existing clay tile liners, the nature of their installation system makes this more difficult to accomplish. For that reason, aging clay tile liners are often simply removed and replaced with an easier-to-install liner.
As their name would imply, cast-in-place liners are built to accommodate the dimensions of a particular chimney. Not only that, but they are constructed inside of the chimney itself. In order to accomplish this, the old liner must first be completely removed, thus exposing the brick wall of the chimney itself. Then a special rubber bladder known as the flue former is placed down the middle of the chimney, and a mortar mix is poured in around it.
Like clay tile liners, cast-in-place chimney liners exhibit a high degree of resistance to heat and the corrosive elements present in chimney smoke. Because they contact the walls of the chimney so snugly, they also provide a higher degree of insulation. This allows higher temperatures inside of the chimney, which in turn means that your fire will burn more cleanly and leave fewer deposits on the walls of the liner over time.
The installation of a cast-in-place chimney liner is less invasive than that of a clay liner. Yet the process can still be a bit daunting. Not only must a chimney crew ascend your roof in order to place the flue former down the chimney, but they must also get a large quantity of mortar mix up there. Prepare yourself by making sure to discuss the nature of this repair with your repair person before they get underway.