Why does nobody talk about how creosote buildup changes with different wood types?

I've been sweeping chimneys for about 3 years now in the Twin Cities area and I noticed something weird last winter. People who burn mostly pine or spruce get this flaky, yellowish creosote that comes off super easy with just a wire brush. But the oak and maple burners? That stuff is hard, shiny, and practically glued to the liner. I swept a house last Thursday where the guy swore he only used seasoned hardwood and the creosote was like tar. Took me twice as long as a pine house. I figure moisture content matters more than species, but has anyone else seen this kind of difference in their regular routes?

2 comments

2 Comments

shah.olivia21d ago

My dad ran a chimney crew in Wisconsin for like 20 years and he always said softwoods give you the dusty stuff because they burn hotter and faster, so the creosote doesn't have time to bake on. The real issue with oak and maple is if the wood isn't bone dry, that moisture turns the creosote into sticky cement. You probably knew that, just throwing it out there.

lilyo3021d ago

Oh man @shah.olivia your dad knew his stuff. The moisture thing is huge, I've seen people toss in damp oak thinking it'll burn slow and it just cakes everything up instead. Softwoods like pine or fir might make a mess but at least it's dry and easy to brush off. Hardwoods are great only if they're seasoned right, otherwise you're asking for a sticky nightmare. Wish more folks understood that before they load up on wet logs.