Black tar or creosote is a byproduct of wood burning that can seep into chimneys and the inside of flues. It can cause long-term issues if it's not removed. Understanding what creosote is and how it can affect the chimney is essential in ensuring the fireplace is safe.

Creosote is one of the most common chimney issues. It’s a type of soot that accumulates in the chimney and blocks the passage. Some of the consequences include obstruction and fires, which is why you should have professional creosote removal promptly.