Cleaned a chimney today that had a 2 inch creosote crust
Got a call from a house in the old part of town, a 1920s craftsman. The homeowner said their fireplace was smoking back into the room real bad. I pulled the cap off and saw this thick black crust, almost like tar. Took me two hours with the rotary brush and a set of rods to chip it all out. After I was done, we lit a test fire and the draft pulled so clean you could see the flame straight up. Anyone else run into buildup that hard on older homes?
Oh man, two inches is wild. You mentioned glazed creosote - just a little heads up though, glazed creosote is actually a specific kind that looks like a hard, shiny, almost black glass coating on the flue walls. What you're describing with the hammer and chisel sounds more like thick, dense stage 3 creosote which is that hard, matte, coal-like stuff. Glazed usually means the surface is smooth and reflective like a mirror, not chunky. Both are nasty to deal with though, no question. I've seen old coal-burning flues that had both types mixed in, real nightmare.
Handled a 1930s colonial last winter where the creosote was so thick I had to chip at it with a hammer and chisel before the brush could even touch it. You ever see any glazed creosote in those old flues?