Putting up Christmas lights today, and while I was on my roof, I decided to look down my chimney. Took off my rain cap and looked down and saw around the rim a build up of creosote curling down. About 2 ft down the chimney looks somewhat clean. Should this be of concern? Thanks for the replys in advance. Oops, anyone help me move this thread to the Hearth Room forum.
Creosote on top of liner?
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Creosote is always cause for concern. If it can fall and collect in a Tee or elbow then there is much more cause for concern. If it falls back into the stove, there is a little less cause for concern.Wacky1 said:
moved per request...
My take is that while creosote is always a concern to some degree, the question is how much of a problem is it? Essentially this boils down to "How much is there?" - It isn't at all unusual to see more creosote at the top of a chimney than there is lower down. Creosote deposits as a condensation product of whatever is left in the stove exhaust gases that don't burn - condensation happens as the smoke cools, which it's going to do as it gets farther away from the fire, plus the chimney surfaces rapidly get cooler as the chimney leaves the conditioned space in the house... This is one of the reasons why we suggest insulating liners if at all possible, it keeps the upper section of the chimney warmer longer, and thus reduces creosote buildup.
When I'm cleaning my chimney, I can easily tell when I cross ceiling / roof line, as the crud deposits double in thickness, and it gets several times harder to push the brush up through them...
In your case, I'd say that the deposits are only a reason to be highly concerned if they are thick enough (>1/4" thick) to need cleaning, and then just for that reason... Of course, if you are up there anyway, it isn't going to hurt to give them a quick brush, but I wouldn't panic about it...
Gooserider
My take is that while creosote is always a concern to some degree, the question is how much of a problem is it? Essentially this boils down to "How much is there?" - It isn't at all unusual to see more creosote at the top of a chimney than there is lower down. Creosote deposits as a condensation product of whatever is left in the stove exhaust gases that don't burn - condensation happens as the smoke cools, which it's going to do as it gets farther away from the fire, plus the chimney surfaces rapidly get cooler as the chimney leaves the conditioned space in the house... This is one of the reasons why we suggest insulating liners if at all possible, it keeps the upper section of the chimney warmer longer, and thus reduces creosote buildup.
When I'm cleaning my chimney, I can easily tell when I cross ceiling / roof line, as the crud deposits double in thickness, and it gets several times harder to push the brush up through them...
In your case, I'd say that the deposits are only a reason to be highly concerned if they are thick enough (>1/4" thick) to need cleaning, and then just for that reason... Of course, if you are up there anyway, it isn't going to hurt to give them a quick brush, but I wouldn't panic about it...
Gooserider
Creosote often tends to build up (waxes), dries, curls, and then falls down the flue. If it can collect in a Tee or elbow, it can sit there like a ticking time bomb waiting to be ignited by an event. Seldom does it ignite at the top of the flue where it waxes.
Ok, so if it is less than 1/4", not to worry? My build up is maybe 1/8" real thin, just around the edge of the liner it has slightly more build up. And yes the build up is where the clay top meets my brick. I thought maybe I did not have the insert hot enough to reburn properly? I don't think it can fall back into the insert, got a baffle in the top, never saw any of what I bumped off and fell down the liner in the box. If a small piece fell down should I worry or will it burn up when I get the insert up to temp? I have had hot fires in the insert just since Thursday. I had a 700 temp on the face of the insert, so maybe 800-850 up top. I just thought that this insert was to eliminate alot of the buildup problem. I never noticed this before with my old insert. The wood I am burning is red oak about 1 1/2 yrs cut doesn't seem real wet, don't have a meter but when you smack 2 splits together they sound hollow. I will have to have the insert removed to clean out I am guessing.
If you mean the baffle inside the insert, any creosote curls that land there will burn safely. Doesn't sound like you have anything to worry about. I was picturing a large curly black popcorn like sculpture in my mind's eye.Wacky1 said:
Wacky1 said:
If it's thin, not really a problem, I wouldn't worry about it... Even small chunks falling down aren't going to be an issue - it takes a sizable pile or a really thick buildup to be a problem - the 1/4" thick layer calling for cleaning is really a conservative, safe limit - if you clean at that level, you won't reach the point where it's a hazard. Unless you have a lot of elbows or twists in your liner, stuff that falls will end up in the firebox or baffle, where it will get burned, so again not a problem.
Sometimes an EPA stove will look like it's giving more deposits, simply because what there is can tend to concentrate right at the top of the chimney - so it looks thick there, even though the rest of the flue is clean... Another factor is that modern stoves are designed to put most of their heat out into the room, and send less up the chimney, so your actual flue temps are cooler, which again causes more condensation of the little bit of crud left in the smoke...
Your wood sounds like it should be OK, though the "clunk test" really isn't that reliable - the only way to be really SURE is to use a meter on the inside surface of a freshly split chunk... (and red oak can take a LONG time to season...)
At this point, it doesn't sound to me like you have a lot of reason to be concerned, I would just keep an eye on things, and especially try to watch how much smoke is coming out of your stack - if you are only getting significant amounts of visible smoke when you are just lighting up, or after a reload, you are almost certainly burning well and properly. It is only a sign of problems if you get smoke after you have a good burn going...
As to the cleaning - if you have a properly installed liner that goes from the stove outlet to the top of the chimney, which it sounds like from your description, you shouldn't ever need to pull the insert out to clean it. You MAY need to pull some parts like the baffles and / or secondary burn tubes out in order to let the crud fall from the flue down into the firebox, but this is usually pretty easy - see your stove manual for details, as the exact procedure varies... If you have a liner that only goes part way up the chimney, then you have a "direct connect" type install, which is a really bad way to do things as it does require you to pull the insert for cleaning... (This is why we encourage the full liner installs, among other reasons...)
Gooserider
Gooserider said:
Thanks Goose. I only get some smoke at light ups and reloads, other than that, nothing much to speak of. As for the liner being insulated, not sure, although I am thinking not. It is, however, fully lined stainless. From what I can tell a pretty straight shot too. It is, however, an 8" liner whereas PE recommends a 6". Don't think that is a problem. I may have a bit of overdraft once I get a real hot fire going, the installer said he can add a 6" boot on top of the liner if the draft is too much. I do appreciate the replies, they do make me more at ease. I will be checking the chimney more often, just to make sure. Thanks again for all the helpful info!
Wacky1 I'm wondering if the rain cap is slowing the exit of the smoke enough to cause it to cool and produce creosote? While a 1/4" isn't much I take it the flue was cleaned this year and you've only been burning a short time so you're thinking what will it be like at the end of January?
If you insist on a rain cap have a tin knocker mod it so that is raised more and open sided as much as possible. That maybe will let the smoke out without any restriction or backup. Or you can remove the rain cap. The mason that rebuilt our chimney refused to put any type of rain cap on our chimney...said they caused more problems than the prevented.
If you insist on a rain cap have a tin knocker mod it so that is raised more and open sided as much as possible. That maybe will let the smoke out without any restriction or backup. Or you can remove the rain cap. The mason that rebuilt our chimney refused to put any type of rain cap on our chimney...said they caused more problems than the prevented.
savageactor7 said:
Yes, you are right, I just had this insert installed in October this year. And yes, I am wondering what it will be like at the end of my season. The rain cap I have is the same diameter as the clay part of my chimney, and is 8 inches high, from top to bottom.
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