how much is too much creosote?

[got wood?]

I decided I would clean my two chimneys myself this year and got to work this weekend. I have started on the 6" SS class A chimney (roughly 20 feet tall) and used the method I saw last years sweep use (duct tape garbage bag to bottom of cleanout trap, after poking brush and first pole through garbage bag). It went pretty well, minimal mess mostly created when I pulled out the cleanout plug.

So after going to the top and back down with my 6" round steel brush which moved rather well through the mostly straight chimney, I held up the bag of creosote and noticed it had some heft to it. I recalled that folks in the past talk of 1 or 2 cups of creosote, but this is much more than that. Probably closer to 10 cups. Now this is the flue for an older Lopi Endeavor (non-cat) that burns almost 24x7 during the winter months. Last year I estimated just north of 4 cords for this stove. I'll see if I still have the bag and can weigh it.

Does that much creosote sound like too much? I had it cleaned at the beginning of the season last year, and not since. I burn almost all hardwood and last year, admittedly, some of it wasn't as seasoned as I would have liked.

I'll clean out my second flue later this week and use that as a comparison (Lopi Liberty - also non-cat 24x7).

If it's too much I suppose I'll just brush mid-season...

 

[Todd]

The word from the Chimney sweeps Guild is any build up of 1/4" anywhere in your system, it should be swept. I don't think 10 cups of creosote is excessive as long as its the fine powder stuff. I like to sweep mine twice per year just for peace of mind. The last two seasons I average around 1-2 quarts of fine brown powder per sweep.

 

[Highbeam]

I too look for the quarter inch accumulation as a max. Now that I have my own brush setup, the hardest part is getting up there to check the accumulation and I might as well sweep it out while I'm up there. No harm can be done sweeping too much with a poly brush. Maybe wear my roof out.

 

[Adios Pantalones]

In a 20' pipe- that doesn't sound like too much to worry about nor little enough to brag about. I think you're in a good place.

 

[North of 60]

There is also a difference between grey ash and black scaly/fuzzy creosote. Did any of it have a glaze. Thats the stuff that
can get you into trouble as it still has fuel left in it. Just another thought that may help.
N of 60

 

[BurningIsLove]

I get 10-15 cups out of the trap each year, most of which I produce when I'm not burning 24x7. My masonry setup, even tho internal, is about 30' from stove to exit. So it takes hours to warm up as it's a double flue (the other being the oil furnace which is never on), and during that warm up time it's creosote-buildup central. Of course, once it finally heats up, the draft is real nice.

 

[saichele]

I wouldn't worry about it.

I have a 25' run of 8" pipe I just swept this weekend, and generated maybe a gallon, maybe a bit more. But I didn'tsweep it last year, and as a result we've probably run 10 full cord through it. (was up inspecting the chimney crown, looked down it, and it looked pretty clean so I ignored it). And it was really fine sandy stuff.

I had a Napoleon at the old place venting into a 12' run of 6", and it would actually clog on occasion. We'd get 2 or 3 cord into a winter, and I'd have to drag my butt on the roof. It was the chunky coal like stuff too.

Steve

 

[got wood?]

A gallon...well that's good news for me. I'll be cleaning the other flue with weekend, so I'll let you know how far off they are from one another. I'll see if I can remember to take a picture to compare what the creosote looks like (flaky, small pebbles, etc).