What causes chimney fires?
The buildup of creosote along the chimney lining walls is caused by restricted air supply, unseasoned wood, and cooler than normal chimney temperatures. Creosote is a black or brown residue that can be crusty and flaky, tar-like, drippy and sticky or shiny and hard. All forms are highly flammable.
Chimney inspections should be done once a year to be sure that everything is working as they should be.