Is Your Smoke Chamber Damaged? Let CinderBox Chimney Services Restore It By Parging It Smooth

When it comes to the safety and efficiency of the chimney system, one of the biggest determinants is the smoke chamber. This area is right under the chimney flue and connects the flue to the firebox area. Although it’s typically far from the minds of homeowners, the smoke chamber should definitely not be overlooked, because a damaged or poorly built smoke chamber can rather easily lead to a house fire and a host of performance issues, including smoke problems and poor draft.

Here are some of the most common problems we find with smoke chambers:

  • The smoke chamber is unlined. What’s the problem with an unlined smoke chamber? Well, since it is the area just above the fire itself, the smoke chamber will likely absorb some of the heat produced by the fire. If the smoke chamber is unlined, this absorbed heat can transfer to nearby combustibles within surrounding walls and framing, potentially causing a fire.
  • The smoke chamber is cracked, crumbling, or developing holes. Just as an unlined smoke chamber can transfer heat to nearby walls and framing, a smoke chamber that is crumbling or riddled with holes and cracks can do the same. Additionally, a smoke chamber that’s damaged in this way can allow the gases and smoke produced by the fire to access other areas of the home. And with holes, cracks, and rough surfaces to slow down the passage of hot gases and smoke as they exit the chimney, these byproducts can linger and flow back into the air supply of the home, negatively impacting air quality and posing health risks.
  • The smoke chamber is corbelled or stepped. The smoke chamber should be smooth and shaped like an upside down funnel, not jagged and stepped. Unfortunately, many are jagged and stepped, which can slow the passage of smoke and gases, decrease performance, and increase the amount of smoke that ends up backing up into your home.
  • The smoke chamber is lined with creosote. Creosote is a byproduct of incomplete combustion and is a highly flammable and corrosive substance that can settle along the smoke chamber and flue walls of your chimney system. Unfortunately, if it’s not removed, it will continue to build up, reducing the size of the flue, slowing the passage of byproducts, and leading to even more creosote buildup and possibly a chimney a fire. Learn more about creosote and the creosote removal process here.

So what can be done if your smoke chamber is unlined, corbelled, or damaged? We can parge it smooth! Parging simply refers to the process of sealing cracks and holes, smoothing over and insulating the entire inside surface of the smoke chamber, and getting rid of any jagged edges. Here at CinderBox Chimney Services, we use the most trusted materials and products for parging smoke chambers and our technicians are certified and experienced to do the job. The result is a smoke-tight, smooth, insulated surface that encourages air flow and leads to a safer, better performing system.

If your smoke chamber is damaged or in need of some TLC, don’t put off repairs. Call on CinderBox Chimney Services at 317-442-8440 or use our online appointment request form to request an appointment today — we guarantee expert results!


Sometimes a fireplace facelift or changeout is the best course of action to keep your system looking good and functioning properly. Let us know today if you think you need this chimney repair or if you have questions about it.