Your Smoke Chamber & Why it Matters

Chimney parging ranks as one of the most common chimney repairs, according to the Chimney Safety Institute of America (CSIA), but it is a repair that most people know little about. So what is smoke chamber parging, and why is it so important?

About your smoke chamber

The smoke chamber is the area just above your firebox. It angles from the wide area of your fireplace to the narrower opening of your chimney to funnel smoke from the firebox into the chimney. An improperly sized or improperly constructed smoke chamber can impede the flow of smoke into your chimney, causing a bad draft. When your chimney isn’t drafting correctly, smoke flows back into your home rather than up your chimney.

When smoke chamber parging is needed

In many chimneys, especially older chimneys, the walls of the smoke chamber are constructed from brick. The bricks are laid in a “stepping” pattern toward the chimney. The CSIA recommends that all smoke chambers have smooth walls, and most building codes require it. Jagged steps of older smoke chambers can impede your chimney’s draft. That means smoke can flow back into your home, and more heat transfer between your fireplace and the surrounding home structures. In the case of an uneven, or corbeled, smoke chambers, the CSIA recommends parging.

Additionally, parging can be recommended when the bricks of the smoke chamber break down. The walls of smoke chambers can be damaged by fire, or the inner core of the bricks can become exposed over time, threatening the strength of your smoke chamber. In cases where the walls of the smoke chamber are not smooth, or where the masonry of the smoke chamber is wearing down, the CSIA recommends parging of the smoke chamber to improve the chimney’s draft and strength.

How smoke chamber parging is done

To parge your smoke chamber, we use a refractory mortar to smooth out the “steps” of your uneven smoke chamber or to rebuild the walls of your damaged or deteriorating smoke chamber. The refractory mortar holds up to the heat of your fireplace, enhancing its strength, and the newly smooth surface will improve your chimney’s draft, preventing smoke from flowing back into your home.

Determining whether your smoke chamber needs to be parged

You may notice some subtle signs that your smoke chamber needs to be parged, such as smoke flowing back into your living spaces or soot stains forming at the top of your hearth, above your firebox. A peek inside the smoke chamber may reveal cracks or exposed bricks. The only way to determine whether your smoke chamber needs to be parged is through a chimney inspection. During your inspection, your certified chimney sweep will examine the smoke chamber to see whether it is corbeled or showing signs of wear or damage.

If you have noticed that your chimney isn’t drafting properly or if you are overdue for a chimney inspection, call the Chimney Care Co. today, and our chimney experts will help you determine whether your smoke chamber needs to be parged.