A Guide to Smoke Chamber Issues

Between your fireplace and chimney flue is an area called the smoke chamber. Its purpose is to smoothly channel smoke, gases and hot air from the firebox to the flue. Issues with the smoke chamber often go unnoticed, because it’s located in a place that’s hard to get to and impossible to see.

Corbelled smoke chambers

It’s common in older homes to find smoke chambers that were built with a technique called “corbelling.” This process staggers the chamber’s bricks, similar to steps, as the area narrows closer to the flue opening.

Corbelling can lead to problems such as:

Deterioration of mortar joints that hold the bricks together: When this happens, toxic flue gases and extreme heat can “bleed” through the chamber and into adjacent areas including the air within the home.

Sluggish drafting: The un-smooth chamber surfaces created by corbelling can impede the drafting of smoke, which will make fires harder to start and keep going and could send smoke and deadly carbon monoxide back into the room.

Creosote buildup: Jagged sections of the smoke chamber are perfect for trapping flammable creosote that forms when wood fires are burned. Many fires that are called “chimney fires” are actually smoke chamber fires.

Smoke chamber parging

Professional chimney and fireplace technicians can parge your smoke chamber. Parging involves smoothing out rough areas within the chamber either by filling in specific sections or adding a complete smooth compound to all the chamber’s surfaces.

Smoke chambers in older homes often need to be parged to prevent the above and other negative effects due to corbelling. Newer homes also may need some level of smoke chamber parging if cracks, holes or jagged areas are present.

Only a licensed technician, preferably one who is certified through the Chimney Safety Institute of America (CSIA), should perform smoke chamber parging. An untrained individual or “handyman” could cause significant problems within your smoke chamber due to a lack of understanding of ventilation principles and masonry building techniques.

The advantage of having your smoke chamber parged

Professional parging is advantageous to you as a homeowner in several ways:

• Your fireplace will draft better and operate more efficiently
• You’ll add many years of life to your smoke chamber and your overall fireplace/chimney system
• Less creosote in the chamber means less chance of a fire
• Less creosote also means less time involved and less expense in having your chimney system swept

Annual fireplace and chimney inspections

The only way to know the exact condition of your smoke chamber is through an inspection by a CSIA-certified chimney expert. Basic inspections should be scheduled once a year, with more involved inspections performed if specific damage is known or suspected.

The smoke chamber is one of the areas of a fireplace/chimney system that the average homeowner is unqualified to inspect and work on. As with the chimney liner and interior chimney masonry, your smoke chamber is basically hidden, and problems with it may not make themselves known until a very serious and dangerous issue exists.

Don’t wait for a disaster. Call Black Moose Chimney & Stove of Antrim, NH, today at (603) 525-7905. We’ll send a licensed, CSIA-certified technician to your home to perform a smoke chamber inspection and evaluation so you’ll quickly know if specialized work is necessary to restore it to safety and top performance.