How Clean is Clean Enough?

[JotulOwner]

I had my stainless (double wall insulated) chimney cleaned today for the first time (last season was my first burning wood, and much of my wood was not seasoned well enough). The sweep ran a brush once from the top down (and back up, of course) and got out about a regular sized coffee can worth of granular looking black material. I couldn't help noticing that, when he was done, there was still a layer of chocolate colored material remaining. I don't expect to see a shiny new pipe after cleaning, but I also don't know what is "clean enough" to be considered acceptable. The stove pipe also had some spots that looked like they could be cleaner. He used a softer plastic bristle brush to clean the stove pipe so there may be a thin layer of material remaining (a little bit more in spots).

I am inexperienced at this, but knowledgable enough to raise questions I can't answer (if that makes sense). He isn't CSIA certified and when I asked if there was any glazing at the top, he didn't know what I meant. That's when I started wondering about everything. I worry about chimney fires, but maybe I worry too much (or maybe you can't worry enough - who knows?).

I'm not saying he did a bad job, I just don't know. Any input would be appreciated.

Thanks

 

[Jimbob]

I usually sweep mine better than that, But I think you'll be okay

 

[Corey]

It's going to be pretty hard to put a number on. A low smoldering fire may allow creosote to build up several 1/8ths of an inch thick with no problem. A hot fire may burn off a small build-up and you'd never even know it. I would say a 'light coating' wouldn't be such a big deal, but if you see obvious 'thickness' to the deposits or you see runs or drips down the inside of the pipe that appear to 'stand up' from the surface, you might want a little more thorough cleaning. What you don't want is a thick, tarry deposit along substantial sections of the flue.

FWIW - I usually scrub my poly brush back and forth 2-3 times in the first 4 feet of flue (down from the top) as this is where I seem to get the most build-up (as a light flaky powder) then I run the brush one time down the rest of the length of pipe. I usually do that once before I start burning - hopefully late October and once when I'm up on the roof taking down Christmas lights (early January) - and that is about it.