Chimney creosote question.

[tomahawk]

So I cleaned my chimney today and this is what it looked like. I cleaned this only 2 months ago before the burning season started. I normally clean it about every 2 months but this is the worst I have seen it in such a short time. Any ideas on what could cause it to build up that fast? It is at the 90 where it exits the house and the outside pipe was not near as bad. I have been burning a lot of Alder this year but the MM says 20% or less so it shouldn't be the wood. I have had lower temp fires until the last 2 weeks so is this such an airflow out - smolder combo type of issue? Any ideas will help. I'm just glad I decided to clean it today.

 

[EatenByLimestone]

I've always had more on horizontal pipe than on the vertical pipe.

How are you checking the moisture? Are you splitting the split and then checking on a fresh face? If so, I'd be burning hotter fires.

 

[begreen]

When you are measuring the wood moisture is it on a freshly split face of the wood? Were the lower stove temps intentional or is it the alder?

 

[tomahawk]

The readings were on a newly cut piece, but they were done on some of the outer pieces in the stack - may dig deeper in to see what the % is farther in.

The temps were low intentionally so as to not over heat the house. Beginning of the year we're in that range of being cold enough to need a fire but not cold enough to really crank it open. The large amounts of alder probably don't help much either.

 

[begreen]

Alder is fine unless it's damp or punky.

 

[red oak]

I think the creosote is the result of not burning your fire hot enough, a common mistake during shoulder season. I think burning a hotter but shorter fire should help.

 

[Backwoods Savage]

The readings were on a newly cut piece, but they were done on some of the outer pieces in the stack - may dig deeper in to see what the % is farther in.

The temps were low intentionally so as to not over heat the house. Beginning of the year we're in that range of being cold enough to need a fire but not cold enough to really crank it open. The large amounts of alder probably don't help much either.

Can you please explain that in bold above?

The reason for asking is to determine for sure how you are measuring with the MM. You don't want a freshly cut piece, you need a freshly split piece. A huge difference there. Also it pays to stay with the grain rather than cross grain.

Seeing a chimney this way after 2 months, I would automatically blame it on the wood. So if the wood is not ready and then your burn it on low rather than a hot fire, that is a sure prescription for creosote like you have.

This can be a positive thing for you. Over in The Wood Shed we frequently tell folks to get on the 3 year plan. That is, get 3 years ahead on your wood supply. If you do that (count time only after being split and stacked) and stack it right, top cover only, you will be amazed how much better that wood stove operates and one of the best parts is that you will actually burn less wood but get more heat.

Good luck.