What It Does

The flue is your chimney’s exhaust pipe. It carries smoke, gases, and sparks safely out of your house. When it’s clean and lined correctly, air moves freely and everything works as it should. When it’s cracked, blocked, or missing a liner, heat and fumes can leak into the home instead of escaping through the top.

What Can Go Wrong

Here’s what homeowners often see:

• Smoke spilling into the room when starting a fire

• A lingering smoky smell even when the fireplace isn’t in use

• Bits of tile or debris in the firebox

• A chimney inspection report that mentions cracks or missing liners.

Older chimneys may not have liners at all. Without one, the brick and mortar absorb heat and creosote, which can lead to fires or carbon monoxide leaks.

How the Pros Fix It

Professional sweeps use cameras to inspect every inch of your flue from top to bottom. They can find cracks, gaps, or missing mortar joints that aren’t visible from below.

If repairs are needed, many sweeps use HeatShield ® Cerfractory Flue Sealant. It’s a hybrid material that combines the strength of ceramic with the heat resistance of refractory cement, creating a smooth, durable repair without tearing the chimney apart.

If there’s heavy creosote buildup, they’ll use products like PCR, Cre-Away, or ACS to safely remove it before sealing or relining.

The Products They Trust

HeatShield ® Cerfractory Flue Sealant: Used to repair cracks or missing joints in masonry chimneys, restoring strength and smoothness without full reconstruction.

PCR: Breaks down and removes tough, glazed creosote from flue tiles or liners.

Cre-Away: Converts thick, stubborn creosote into a brittle form that flakes off easily during normal heating and cooling.

ACS: A spray treatment that attacks dangerous creosote and soot, helping prevent chimney fires and keeping the flue cleaner longer.