Why Chimney Flue Tiles Crack & How To Fix Them

No matter whether your chimney vents a fireplace, wood stove or furnace, it likely contains a section of clay flue tiles linked together to form the chimney lining. 

This flue liner should be well sealed to protect the efficiency and soundness of your chimney. But over time and usage, problems and defects can develop that threaten the safety of your chimney. Cracked flue tiles are one of the most common problems homeowners deal with. 

Cracked flue tiles

Cracked tiles frequently occur when the heat is not evenly distributed throughout the chimney. This causes the tiles to expand in an uneven fashion and the result can be cracking, buckling or splitting. Clay tiles are most likely to have this problem because the material does not quickly absorb heat.

Flue tiles can also crack due to sudden events such as a chimney fire or lightning strike. Inferior craftsmanship of the chimney, or even the ongoing settling of your home, can also cause cracked flue tiles.

Finally, exposure to corrosive chemicals and moisture can cause pieces of the flue liner to delaminate. This process is known as “spalling.”

Why cracked flue tiles are dangerous

Cracked flue tiles can lead to gas leakage that allows carbon monoxide to seep into your home’s interior. 

Combustible creosote or soot can escape through the openings in the cracks and gaps and build up outside of the flue liner. If the creosote catches fire in your chimney, very serious damage to your home can occur because the fire will no longer be restricted to the flue. 

Pieces of flue tile that break off due to spalling can then form dangerous blockages within your chimney.

Loss of chimney efficiency

The defects caused by cracked flue tiles, gaps, and spalling can begin a process that not only threatens your family’s wellbeing, it can begin destroying your chimney from the inside out.

In order to work efficiently, chimneys must be free of gaps and cracks so that gases can’t escape. Chimneys are like straws. If a straw has a crack or hole in it, liquid won’t flow through it properly. 

Cracks and gaps allow extra air into your chimney. They also slow the flow of smoke and gases rising up and out. As a result, your fireplace, wood stove or furnace will diminish in heat-efficiency.

How to fix cracked chimney tiles

The best way to fix cracked tiles is by lining or relining the chimney itself. 

Typically, the preferred option for a chimney liner is stainless steel. Stainless steel comes with a lifetime warranty and usually never needs replacing.

If you have concerns about cracked flue tiles, don’t hesitate to reach out to ChimneyTEK.