Unparged Smoke Chambers

What is a smoke chamber?

The smoke chamber is the area located directly above your fireplace damper. When you build a fire and the smoke travels through your damper opening, the smoke chamber is the passageway that funnels the smoke from the damper opening to your chimney liner. There are building codes that have placed specific requirements concerning how these smoke chambers are constructed. Basically, the smoke chamber should be parged smooth with high temperature mortar. The two main reasons why this is important is that building materials can be located just on the other side of the brick which could lead to a potential fire hazard. A layer of high temperature mortar helps prevent heat from transferring through these brick. The second reason why a properly parged smoke chamber is important is that a smooth smoke chamber transition will allow smoke to travel at a quicker rate up the chimney. A faster draft decreases the amount of creosote build up and decreases the chance of a chimney fire. 

Properly parged smoke chambers

Here are photos of smoke chambers that are not parged.

Repair of smoke chambers: To repair a smoke chamber, a chimney technician usually will cut out the damper frame and parge the corbeled brick with high temperature specially designed smoke chamber material. This repair will allow smoke to properly pass from the firebox to the chimney liner. The photo below is a repair from the photo directly above.

Finally, when a chimney technician recommends to have a smoke chamber parged, it is important to understand the science behind this statement. The answer is that the engineering behind residential construction is founded on the requirements of building codes. The most widely adopted building code in the United States is the International Residential Code and it clearly states the requirement for parging a smoke chamber smooth. We hope this section of our frequently asked questions has been informative and feel free to check other sections of our website.