There is nothing like sitting in front of a traditional open fireplace on a cold winter day. Listening to the fire crackle, feeling the warmth and getting hypnotized by the flames is not a bad way to spend an evening in the winter. However, ensuring the fireplace and chimney flue are in good working order is very important to the safety of the fireplace. Something as small as a cracked flue tile can make the fireplace very unsafe, allowing dangerous gasses into the home. Installing a chimney liner is the easiest way to reline your chimney and get your fireplace back to working order.
Anatomy of the Fireplace
Unlike a wood stove or furnace, a traditional fireplace does not have a direct connection to an exhaust hole. What do I do to connect the bottom of the chimney liner? Before we get to that, we first need to understand the proper anatomy of a fireplace.
The Firebox is what you see and where the wood is burned. Above the Firebox is the Damper. The Damper is the flapper above the fireplace to close it off when you are not using it to prevent down drafts. Above the Damper is the Smoke Chamber. The Smoke Chamber is what funnels the smoke gradually into the smaller flue to prevent downdrafts. A sudden change from a large open fireplace to a small flue would make the fireplace hard to light without smoke rolling out of the front of the fireplace. The Smoke Chamber also helps prevent low wind related downdrafts. Above the Smoke Chamber is the chimney flue. The chimney flue is the channel that keeps the flue gas concealed to safely vent out of the home. Link to Chimney Diagram for a helpful visual.
Terminating the Fireplace Chimney Liner
Now back to the question: What do I do to terminate the bottom of the chimney liner? The proper way to terminate a chimney liner is by parging the liner's bottom plate into place with refractory cement. A Mesh Bottom Plate is available to assist you in parging the chimney liner. There is a collar that will clamp to the liner and mesh to give the cement something to hold on to. You must not bypass the smoke chamber and damper and terminate the liner directly above the firebox. The liner must be terminated above the damper and above the smoke chamber where the existing liner is.
Often times, the Smoke Chamber will also have to be smoothed out and parged with Chamber Tech 2000 Smoke Chamber coating if there are large cracks in the Smoke Chamber. It is common to remove the Damper and possibly some bricks to give yourself enough room to work in the Smoke Chamber. You can install a Top Sealing Damper such as the Lock Top Chimney Damper as a replacement of the throat damper. The Top Sealing Dampers are more energy efficient and can actually make an air tight seal for the fireplace.
Installing a chimney liner for a fireplace can be a little more work than installing a liner for a wood stove. However, the work is worth it. Just think of the next time you will be sitting on the couch in front of the fireplace after a cold winters day, reading a good book and enjoying your favorite beverage.