The Dangers of a Cracked Chimney Flue

There are several reasons annual chimney inspections are recommended by fire safety experts but none as compelling as the dangers of a cracked chimney flue. Some safety hazards are more urgent matters than others. When it comes to a deteriorating chimney flue, the emergency is real. A fireplace or stove should never be used as long as the flue has any type of breach, even if the fracture is a small crack.

The Functions of a Chimney Flue

Prior to 1940, chimneys were seldom built with inner linings. They have been required by law since that time because research revealed startling results. The report stated that building a chimney with no flue or liner is a “little less than criminal.” The four primary functions of chimney liners follow.

Heat Protection

Cracked Chimney Caught on fireA chimney liner prevents combustible parts of a home from being exposed to the extremely hot temperatures in a chimney. The eye-opening National Bureau of Standards (NBS) test that changed things starting in 1940 found that woodwork adjacent to an unlined chimney can catch fire in just 3.5 hours. When your chimney liner begins to deteriorate, the same effect occurs. Your fireplace or stove should not be used again until the chimney liner is repaired or replaced.

Protection from Corrosion

If there is no chimney liner, acidic materials in flue gases are allowed to penetrate brick and mortar. Mortar joints quickly erode, which exposes exterior masonry to moisture. The eventual result is a chimney that begins to lean and might collapse if repairs aren’t made.

Protection from Toxic Gases

Hazardous gases can leak into living spaces in your home if you don’t have a sound chimney liner. With even the smallest of openings in the flue, toxic fumes can endanger your home’s occupants. Among those poisonous gases is carbon monoxide, known as the “Silent Killer” because it is colorless (invisible), odorless, non-irritating, and tasteless. If there isn’t a working carbon monoxide detector in the home, people can lose consciousness before becoming aware that there is a danger.

Ensure Optimal Efficiency

Installing Chimney LinerWhen you have a modern, efficient gas or wood fireplace or stove installed, an essential step in the installation is to ensure that the flue is the proper size. If the flue size is wrong, these appliances cannot deliver optimal performance. A wrong sized liner can also cause excessive creosote buildup, which increases the risk of a hazardous chimney fire.

Types of Chimney Liners

Clay Tile Chimney Liner When chimneys are initially built, they usually always have a clay tile liner. That’s because the material is cost-effective and lasts up to 25 years. Eventually, though, clay liners deteriorate. Repairs aren’t usually a feasible option because partial tear-down of the chimney itself is necessary. In the meantime, other sections of the clay tiles are also suffering from wear and tear and will need to be replaced, as well. The best option is to have an entirely new chimney liner installed.

Cast-in-Place Chimney Liners

Cast-in-place liners utilize cement-like products to create a permanent liner that also improves the structural integrity of chimneys. The primary disadvantage of a liner made with casted masonry materials is that it is cost-prohibitive.

Stainless Steel Chimney Liners

Stainless steel is the material for chimney liners that most chimney professionals recommend. Aluminum is much cheaper but is only a feasible option for a flue material when used with certain medium-efficiency gas heating appliances. Stainless steel, on the other hand, often comes with a lifetime warranty.

Schedule a Chimney Inspection with Chimney Solutions

Contact our certified chimney sweeps at Chimney Solutions in Alpharetta, GA, to schedule a chimney inspection. It’s very difficult to identify damage in a chimney flue unless you have an inspection. Specifically, a Level 2 inspection includes the use of a special video camera that provides a view of the chimney liner from top to bottom. We also offer fireplace sales and the full range of chimney maintenance services, including chimney cleaning, masonry repair, flashing installation and rebuild, chimney crown repair, and more. Give us a call today at (770) 771-5501.



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