Between the firebox and the flue of your Riverside fireplace is a funnel-shaped space called the smoke chamber. You rarely see it, and it is easy to forget, but in the older homes throughout Riverside's historic district it is one of the parts most likely to be rough, corbeled with exposed brick steps, or deteriorated — and that matters for both draft and fire safety.
What the smoke chamber does
The smoke chamber gathers smoke and gases rising from the firebox and compresses them smoothly into the narrower flue above. When it is smooth and correctly shaped, smoke flows up easily. When it is built with exposed, stepped brickwork — common in older construction — those ledges create turbulence, catch creosote, and slow the draft, which is why some historic fireplaces smoke no matter how well you burn.
Why a rough or damaged smoke chamber is a hazard
- Exposed mortar joints and brick ledges collect flammable creosote where it is hard to clean
- Gaps and deteriorated mortar let heat reach the surrounding structure
- Turbulence reduces draft, pushing smoke back into the room
- It is a common weak point that inspections of older chimneys frequently flag
How parging fixes it
Parging is the process of coating the smoke chamber walls with a smooth layer of refractory mortar, filling the stepped brick and sealing the joints. The result is a smooth, insulated surface that improves draft, removes the creosote-catching ledges, and restores the fire-safe barrier the smoke chamber is supposed to provide. On historic Riverside homes it is done carefully to preserve the working fireplace without altering the visible character of the house.
When to look into it
If your older fireplace smokes despite a clean flue and good burning habits, or if an inspection has noted a rough or open smoke chamber, parging is often the fix. It is the kind of hidden repair that quietly solves a draft problem homeowners have lived with for years.
Homeowners in Riverside can read more on our Riverside chimney sweep page, or see our full chimney repair and masonry service.
Older fireplace not drafting right?
Careful work, up-front pricing, seven days a week in La Grange and the western suburbs.
Call (708) 432-5330Frequently asked questions
What is a smoke chamber?
It is the funnel-shaped space above the firebox that channels smoke into the flue. A smooth smoke chamber drafts well; a rough or damaged one causes smoking and collects creosote.
What is smoke chamber parging?
Coating the smoke chamber walls with smooth refractory mortar to fill exposed brick steps, seal joints, and improve draft and fire safety.
Why does my old fireplace smoke even when the flue is clean?
A rough, stepped, or oversized smoke chamber is a common cause. The ledges create turbulence that slows the draft. Parging often resolves it.
Is the smoke chamber checked during an inspection?
Yes, a thorough inspection of an older chimney examines the smoke chamber, since it is a frequent weak point for creosote and heat exposure.
Written by Adam Evans, owner of Chimney Sweep Brothers and a chimney technician with 12 years of experience serving La Grange, IL and the western suburbs.
Published: September 27, 2026