Found a weird creosote buildup pattern in a 90-year-old house

I was sweeping a chimney in an old Victorian in Portland last month and found this greasy, almost tarry layer near the smoke chamber that I'd never seen before. Turns out the homeowner had been burning wet wood from a cheap supplier for two years straight. Has anyone else run into that kind of sticky residue and found a good way to clean it off without damaging the flue?

2 comments

2 Comments

williamschmidt9d agoMost Upvoted

Man, that reminds me of a buddy of mine who bought an old farmhouse upstate. He got a deal on a truckload of "seasoned" firewood from some guy on Craigslist. Six months later his flue looked like a tar pit. He tried one of those chemical soot destroyer logs and it actually helped break it up enough that a regular brush could handle the rest. Still took him an entire weekend to get it clean though.

the_stella9d ago

I mean, idk, I kinda have to push back on the chemical log thing a little @williamschmidt. I've seen those logs leave behind a weird crust that's even harder to scrub off if the creosote is really thick and tarry like what you're describing. Maybe it's just me but I'd be nervous about trying a shortcut with that sticky wet wood residue, it can turn into a real mess if it doesn't fully break up. I'd start with a poly brush and some patience, go slow with elbow grease before risking a chemical reaction making it worse. That's what I'd do anyway.