Common Chimney Repair Problems

What Makes Chimneys Deteriorate?

Across the nation, chimneys and stacks can be seen in America; however, like most things, they are not meant to last forever; the usual lifespan ranges between 25 to 30 years. Their lives are determined by the environment. However, with the right care and maintenance, most can continue to serve for years without needing any chimney repair.

Causes and effects

Chimneys start to deteriorate from the moment they are erected and before they are actually used. The pace of deterioration differs. In the early years, there will be no apparent signs; however, in subsequent years, deterioration will often accelerate quickly, often catching people off guard and requiring major repairs instead of maintenance. Without an adequate maintenance program, sadly, deterioration is a foregone conclusion.

Reinforced concrete chimneys have two major causes of deterioration. The first comes from the flue gas itself. Combustion of oil and sulfur-containing coal does produce corrosive forming components that will start to attack the calcium silicate hydrates that strengthen concrete. Gases bleeding into the space between the liner and chimney condense and form an acidic liquid. If this is left to reach the reinforced steel, corrosion-induced cracks, spalling and delamination will be the result.

A second form is when the liner starts to deteriorate, and the chimney is exposed to hot gases directly. Metal liners have either an exterior liner to maintain a “hot side” temperature just above the point of acid gases or an interior acid-resistant go. As if this is damaged or saturated, or the original coating fails, holes will start to appear in the liner, allowing the process gas to come into contact with the chimney. At which point, the stress will be both chemical and thermal.

If you would like to make an appointment to discuss chimney repair, please contact Flathead Chimney and Dryer Vent Cleaning Services at (406) 249-5732 now if you live in the Coram, MT region.