Creosote: Causes, Dangers, and What You Should Do About It


Wondering why black flakes are coming out of your chimney? Then you’re not alone. These black flakes are a common occurrence in fireplaces known as creosote. However, just because it regularly forms doesn’t mean that it should be ignored. Let’s take a look at what causes creosote buildup in chimneys, why it can become a problem, and what can be done about it.

What Is Creosote?

Creosote is naturally created during the combustion of wood and other fossil fuels. When the chimney lacks proper airflow, the fire doesn’t get enough oxygen for thorough combustion. The non-combusted particles then flow upward from the flames through the smoke and mix with the cold air and water in the chimney’s interior, condensing as a result. This solidified residue is creosote and may appear puffed and flaky while being colored dark gray, brown, or solid black. There are varying stages of creosote, which become progressively harder to deal with.

Stage 1 Creosote

Creosote first starts out as loose and dusty powder deposits. This stage of creosote is relatively easy to clean.

Stage 2 Creosote

In the second stage, creosote thickens into a tar-like deposit — these are the hardened black flakes coming out of your chimney. They’re more challenging to remove than the first stage, requiring specialized equipment or chemical solvents.

Stage 3 Creosote

The third stage of creosote is very difficult to remove compared to the black flakes coming out of chimneys. Dripping like candle wax when exposed to high temperatures, the most serious kind of creosote is sticky and oily. 

Why Creosote Buildup in Chimneys Is Dangerous

Creosote isn’t just ugly and a hassle to remove — it also poses numerous problems for your chimney and, by extension, the entire household. While the presence of creosote restricts airflow in the chimney, it is also highly flammable and becomes dangerously hot when combusted. The materials your chimney was made from can only withstand certain temperatures, and inflamed creosote will surpass that limit. As a result, creosote is one of the top causes of chimney fires and has even led to house fires.

Not only can creosote be a major fire hazard, but it’s also highly toxic. Creosote can create many health problems when left unchecked, including irritated eyes, skin, and respiratory issues, among other issues — creosote is possibly carcinogenic as well.

What Can Be Done About Black Flakes Coming Out of Chimneys

Because creosote naturally forms when burning wood, preventing its formation can be tricky. This problem can’t be solved with time, as creosote won’t go away by itself. Not only that, but as more of it accumulates, the air ventilation in the chimney is reduced — thus making it easier for creosote to form. If this is allowed to continue, it will prevent any air from passing through and making the entire structure unusable.

If you don’t want black flakes coming out of your chimney, then don’t use them at all. However, nobody will want to give up the warmth of a fireplace, especially on a cold winter evening. While you can’t prevent creosote from forming outright, you can take steps to ensure it won’t become a serious problem. Ensuring your chimney is well-ventilated will help mitigate the formation of creosote, and having professionals maintain and remove any buildup will also keep your fireplace safe.

When you need to remove creosote and aren’t sure where to begin, Chimney Heroes will be there to help. We offer a wide range of professional services, including gas stove installations and chimney repairs in Albany, NY, and the surrounding areas. Call Chimney Heroes today for more information and to schedule your appointment.