I stopped brushing flues top-down after 12 years and my creosote numbers dropped
Everyone in my local group swears by brushing from the roof first and working down, and I did it that way for over a decade. In March I started doing the bottom-up pass first on a test run of 30 jobs around Akron, just to see if it mattered, and the difference caught me off guard. On a typical 8x8 clay liner I was pulling maybe two thirds of a gallon of soot with the old method before the sweep got clean. Doing the bottom first and finishing top-down got me to under half a gallon on the same style flues, and the dust in the living room dropped enough that two customers asked what I changed. My guess is the bottom pass knocks the heavy shelf loose while the top brush still has room to push, instead of packing it down the whole run. I know this goes against what most of us were taught, so I want to hear it. Has anyone else flipped their order and seen the same thing, or am I just getting lucky on soft creosote?
Heard a guy on a chimney podcast say the same thing, that the bottom pass breaks the shelf before the top brush packs it down. Makes sense on soft creosote for sure, but I'd want to see it on the glazed stuff before I fully buy in. Keep us posted if the numbers hold up past 30 jobs.