Understand the Dangers of Creosote Buildup

Fireplace safety is crucial if you want to enjoy the warmth and charm your gas or wood fireplace provides. One way to keep your fireplace safe throughout the winter is by monitoring creosote buildup. An excessive buildup of creosote can prove dangerous for a variety of reasons, plus it can impact your fireplace's longevity.

Read on to learn more about creosote, how it affects your fireplace, and the steps you can take to keep your fireplace in good condition.


What Is Creosote?

Creosote is a combination of tars and various other chemicals produced as a byproduct of burning wood or fossil fuels. Small amounts of creosote mingle with the smoke that rises to the top of the flue. Along the way, the creosote combines with moisture and adheres to the flue liner or open brickwork of the chimney, creating a thin layer of tar that solidifies as it cools.

Creosote has had plenty of interesting uses throughout history, including as the active component of various medicines. These days, creosote is used in commercial applications to treat and preserve wood for increased longevity and durability. Creosote is responsible for giving smoked meats their distinctively smoky flavor, plus it's also the special ingredient behind artificial liquid smoke flavoring.


Why Is It Dangerous?

Creosote buildup never goes away on its own. Once a layer of creosote forms, it's there for good until it's physically removed. Without proper cleaning, multiple layers of creosote will steadily build up every time you use your fireplace. This buildup causes the flue to narrow, reducing the amount of ventilation available to your fireplace.

The resulting lack of fresh air prevents your fireplace from burning its fuel efficiently, resulting in a smaller, dirtier flame that causes even more creosote buildup. The cycle continues until your flue becomes completely blocked with creosote, rendering your flue liner unusable.

Creosote is also highly flammable, especially when it accumulates in large amounts. Excess amounts of creosote can ignite when exposed to enough heat from your fireplace. Creosote-fueled fires can spread quickly and with little to no warning, making these fires incredibly dangerous. Failure to clean excess creosote buildup is a common factor behind most home heating fires, according to research from the National Fire Protection Agency.


How Does It Form?

There are several stages to creosote buildup. Each successive stage can prove more difficult to deal with than the last, which highlights the importance of tackling creosote buildup at its earliest stages. How soon creosote buildup occurs usually depends on several factors, including the efficiency and overall condition of your fireplace. If you're using a wood fireplace, the quality of the wood being used as fuel can also affect creosote buildup.


First Stage

Creosote buildup starts out as a light coating on the flue. Depending on how efficiently your fireplace burns its fuel, the creosote buildup will mostly consist of soot with small amounts of tar mixed together. As a result, the initial stage of creosote buildup appears thin and flaky.

The first stage of creosote buildup is always the easiest to deal with. Fireplace technicians can remove creosote buildup using special-purpose brushes, preventing additional, harder-to-remove layers from forming.


Second Stage

As the creosote buildup continues, the soot is replaced with more tar, giving the creosote a thicker, harder, and sometimes shinier appearance. The overall texture of the buildup remains dry and crumbly, however.

Brushing alone won't remove second-stage creosote buildup. Rotary loops and chemical solvents are the usual go-to tools for fireplace technicians when battling creosote buildup at this stage.



Third Stage

Left to its own devices, the creosote buildup eventually turns into a highly concentrated mass that appears oily and feels sticky when fresh. Repeated exposure to heat usually gives this mass a hardened, shiny appearance. At this stage, a simple cleaning may be extraordinarily difficult, if not impossible. Some technicians even encourage a complete replacement of the flue liner as a more cost-effective alternative to cleaning.



How Can It Be Prevented?

Since it's a naturally occurring byproduct of the combustion process, there isn't much you can do to completely stop creosote buildup in its tracks. However, taking a proactive stance on fireplace maintenance will help prevent excessive creosote buildup.

Fireplace technicians can spot and take preventive action against the beginnings of excessive creosote buildup during regularly scheduled fireplace checkups. These checkups also ensure that the flue's inner mechanisms are working properly, significantly reducing the rate of creosote buildup.

Most experts recommend having your fireplace inspected on an annual basis. Flue cleanings should be done when there's a 1/8-inch deposit of creosote in the flue.

Prevention is always the key when it comes to creosote buildup. The sooner you can tackle the buildup, the easier it'll be to deal with. To learn more about the effects of creosote buildup or to schedule a professional inspection, contact us at Hartman Heating, Air and Fireplaces today.