TIL about creosote buildup patterns from a job in an old farmhouse

I was out at a 1920s farmhouse near Lancaster last week, cleaning a chimney that hadn't been touched in maybe 15 years. The creosote was layered in thick, shiny strips instead of the usual flaky coating, and it took me twice as long to scrape it all out. Has anyone else seen that kind of layered buildup on older chimneys, and does it point to a specific burning problem like wet wood?

2 comments

2 Comments

sageburns10d ago

Wet wood definitely causes that shiny layered creosote.

aaronlee10d ago

Wait, are you sure wet wood is the main cause of that shiny creosote? I always thought that was more about burning at too low a temperature over time, not just the moisture content. Like, I've burned some pretty wet stuff in an outdoor boiler and got crumbly black creosote instead of that hard shiny glaze. The shiny stuff seems to happen more when I choke the air down too much and the smoke stays cool inside the pipe. Not saying wet wood can't make things worse, but I think the burn temperature matters way more for getting that layered look.