Creosote running down outside of pipe, inside of house

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Debi

New Member
Hearth Supporter
Nov 28, 2009
46
Black Hills
First, thank you for this forum, and for any input received from my post. We have heated strictly with wood for almost ten years, but we have never installed a stove or piping ourselves, only cleaned the pipes. Our tiny home of three years is heated by our wood stove. We do not have any other alternative heat source, nor a furnace. Friends built the addition to our home and installed our stove a little over three years ago. We clean the pipe with a chimney brush monthly from September through May. The past few days, creosote is running down the outside of the pipe that is inside the house, between the ceiling and the stove. The exterior pipe looks fine. Also, this fall we had resealed around the pipe where it meets the roof. I appreciate your thoughts and suggestions to help us figure out what is going on.
 
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Wood's not dry enough and fire not hot enough.
 
What kind of pipe do you have in the house? If its single wall did you install it with the male end pointing down? Creosote should run back into the stove. You clean the stove very often is that because you always see a good buildup after only 1 month. That being the case then I suspect you are burning wet or green wood. Maybe you have always burned wood thats not properly dried. If you get good dry wood you will not have to clean the pipe so often and you will get considerable more heat out of it.
 
Reversing the pipe is just getting rid of the canary. Creosote should not run, period.
 
It's leaking from the ceiling penetration? What did you seal things with on the roof? Is this a class A stainless chimney going through the roof? Or masonry?

pen
 
Thank you for all your replies so far. I apologize for not having technical knowledge about this and don't have all the info about the pipe used especially because we did not purchase or install it. However, I will attempt to answer your questions best I can. Yes, the male end is into the stove. No, we do not burn green wood. We harvest the wood ourselves and do not take down live trees. All is at least dried a year but nothing too old and punky either. The creosote is coming from between the ceiling rectangular piece and the pipe, then oozing down the outside of the pipe to the stove. We sealed around the pipe at the roof with a heat resistant sealant made for this purpose (sorry, don't have the name of it right now). I believe the pipe inside is a single wall, black. I do know there is a stainless steel liner in the pipe that goes through the roof and is outside, double walled I believe. Regarding why we clean every month, that is my husband's thing ;). He is a bit fanatical about creosote since going through a chimney fire in a two story home we had rented many years ago. That system was not built correctly and it was not a good experience.
 
Debi said:
No, we do not burn green wood...
When I said "not dry enough" I was not implying "green". There is a whole lot of "in between" the two ends of the spectrum. How dry your wood is depends on a lot of factors. Species, size, split or round, how it's stacked, where it's stacked, etc..

How hot you run your flue is also a factor. How humid your indoor air around the stove yet another. If the flue isn't kept hot enough, moisture in the flue gasses can condense. If you over-humidify the air and don't draw outside air, that humidity goes up your flue.
 
Welcome to the Hearth, always looking for new folk to join in, especially from (or near) the Badlands of So. Dakota. Eat your hearts out Easties, you'll never see nothin' like this back there.

I am going to be as vague as possible :ohh: Creosote is the condensation of moisture and volitile gases, pieces and stove cast-offs. This usually occurs when the stack is too cool or the air movement is too slow, or a combination of both. Sometimes folk try and save a buck, run single wall pipe to the rectangle (that's a thimble, and figure they can continue up through the roof. What happens is the hot gases hit that shocking cold attic point and it acts like a chiller, instant cool down. The pipe can be single wall, but should be Class A double wall, or in some cases thriple wall there after. This allows the pipe to retain more heat and move the gasses up. That's about as general as I can get.

There may be more than one thing going on with the stack. First, creosote is building up somewhere and finding a way to drizzle down (that's tech for drip) it could be from a bad pipe seam and some blockage, or from the cap, or lip of the top if no cap. The stove does not generate creasote outside the fire stream. Second, it may not be creosote at all. I had a gas water heater with drizzle down it. Not creosote, not from Natural Gas. It was coming down the stack, from the roof. I have a very old shake shingle roof and a cast flange the water heater was stuck through (house is 140 years old and they reused wherever) I gooped Black Jack and put a new flange and did all I thought would work, no such luck. Ended the problem when I switched to on demand hot water. Took the sucker out. What I found was the flashing and flange were rusted away well under the shingles and simply acting like a wick to direct the flow. The crud was a little of everything that was on or in the roof including the black jack I had tried to stop the flow with.

Where you are diligent about cleaning the stack, you probably are not at risk for a fire, but you should see if you have a condensor going on. Second check the flashing around the stack (I assume it pipe out the roof by your description) and make sure it is good. Squeeze into the attic and see what's going on there.

Once your homework assignment is done, come on back and hit us again.
 
Greetings Debi. If I understand this correctly, you've been burning with this setup for a few years, but this new problem only showed up this year. Is that correct? If so, the first place to look is what changed. Why was the outside flue resealed this year?

Would it be possible to post some pictures of the installation? It would help to see what you are seeing. Maybe post a shot of the outside where the flue exits the roof, including the storm collar and then a shot of the interior problem.
 
LLigetfa, I was referring to "snowtime"'s reply when I said we weren't burning green. Sorry for the confusion, I was lumping all of my answers into one and probably shouldn't have done that. We mostly burn pine that we've split and stacks out here rarely retain much moisture because of our dry climate.

littlesmokey, I realize I haven't done my homework yet but wanted to reply because you people are awesome in the super speedy response department! wow! The Badlands are about 3 hours east of here. We are in the Black Hills on the Wyoming side. Truly paradise! and we love our cowboy lifestyle. Out here, things are done pretty simply and mostly without hiring out because we are in a remote area (the closest WalMart or fast food place is about 60 miles) and they are done with the materials at hand. I really don't know just how this was constructed and we don't have an attic so I will attempt my homework as best I can.

BeGreen, the outside was resealed this year because it basically just dried out, another common thing in our dryer, whole lotta sun kind of place. And yes, this problem just cropped up. I will take a few pix asap and hopefully get them posted correctly.

I sure do appreciate being able to come to such a great bunch of folks!
 
Normally a class A pipe is sealed with silicone which shouldn't dry out with the lower surface temps on class A pipe. I'm wondering if the black goo is not creosote, but the sealant. Could be wrong, that's why the request for the pics.
 
Can we assume you are not deluged with rain that is getting into your chimney? What is different this year from others? Milder weather/slower burns? More humidity?
 
I am not sure what the product was when it was sealed before but I do think it was black colored and I know it was recommended for stove pipes and high heat etc. We chose a silicone this time and was surprised to learn at the hardware store that most people in our area reseal annually.
No, we are not getting rain although October brought five early snowstorms. We have been dry and warmer then usual all November. This problem is real new and well after the last snow. Here are a few pix that I just took a few minutes ago. My hubby tried to scrape off much of it earlier today so it had been quite bit thicker and heavier then what it looks to be in these photos. Hope this helps give you somewhat of an idea. I will stop bugging you all for tonight now :)

[Hearth.com] Creosote running down outside of pipe, inside of house


[Hearth.com] Creosote running down outside of pipe, inside of house
 
BeGreen said:
Normally a class A pipe is sealed with silicone which shouldn't dry out with the lower surface temps on class A pipe. I'm wondering if the black goo is not creosote, but the sealant. Could be wrong, that's why the request for the pics.

Think of your driest day as Debi's wetest. If I get the general location, Winter humidity is in the low teens and in the low twenties for highs. Her drying issues are shingles and sheet stock. I have seen 3/4 in plywood shrink a 1/2 to 3/4 in on all sides. Unsealed and un-protected it falls apart in a few years. That said, things are different on the high deserts.

Based on the pics, I now need to know what kind of roof and how best was it laid up? I assume from your response a structure of roof>frame>ceiling, right? Can you give us an idea of the insulation. I don't think you have a creosote issue personally. Truy washing your pipe with strong detergent and let us know what comes off on the rag. No previews. Just for curiosity, see if you have an air leak up at the thimble, Test with a smokey stick or incense, see where the smoke moves.

Just think of this as extra credit.

BTW, if you wanted to get away, you can't go farther away than where you are. I sometimes miss that solitude. At least you have internet, I didn't even have radio, really tight valley.
 
This may sound foolish, but sometimes the simplest things are overlooked. Did you smell the stuff? Creosote has a very distinct smell that even novice fire burners can usually recognize. I would imagine you'd be getting a petro smell of some sort of that stuff is sealant of any type.

pen
 
Your support box looks to be Selkirk,You do not have a stove pipe adapter on the first pc of class A chimney.I think when it was cleaned last the pipe might have lifted off your single wall pipe. So now it is sucking cold outside air cooling the smoke and condencing into creosote.You need to put on a single wall adapter because it is very unsafe the way you are burning it right now.
 
That looks like it could be roof cement to me. From your description it sounds like whatever they patched with could be leaking down too. Unfortunately, it looks like it could be creosote also. Can your husband get up on the roof to brush the chimney? It should tell you really quickly if there is creosote in the chimney. And also have him check to see what they sealed the chimney exterior with?

Matt
 
Okay Boys and Girls, I think we have this figured out. Seeing that we are having a mild day of sun and 43 degrees, hubby just went up on the roof and starting taking things apart. He pulled out the double walled pipe to get a closer look at the junction to the single walled pipe. (no attic, just ceiling to rolled insulation to white metal roof). Lo and behold, the double walled pipe appears to have been installed upside down. It does not have a male end down, and it basically was just sitting on top the single walled. Unbelievable!!!! and we've used it like this for nearly three years. And the top of the single walled pipe is disintegrating and bent, perhaps from all the pressure when cleaning the chimney?
Our pastor is in Spearfish, SD this afternoon and he is picking up all new piping for us as I type. Tomorrow's predicted heatwave of near 60 degrees will be perfect to put all new piping in and reseal. Any words of wisdom, encouragement, etc for our reconstruction?
I truly appreciate you all taking us by the hand through this and sharing of your considerable knowledge and experience. I am sold on this site and plan on staying, if that's okay with you all!
And littlesmokey, you have us pegged regarding our climate conditions and removal from the rest of the hub-bub. That's the big reason we moved out here. We had enough of the rat race and decided to be brave and step off the planet for awhile. We've never looked back. Scaling down, living simply, getting rid of "stuff" etc has done wonders for the blood pressure. The quality of life is well worth the trade-off.
 
You still need a single wall adapter that hooks up to the class A chimney.
 
Daryl is right on - I don't know what other brands call them but Selkirk sells a chimney pipe adapter. It's available as both a twist lock (if you happen to have selkirk class a pipe), or as a retro adapter which will screw on the your chimney pipe.

It's a little scary to think it was like that for a while. I guess your life stlye change has also brought you some luck that nothing bad had happened to this point.

Welcome to the hearth debi, I'm still new here also. It's a little additive.
 
If it was upside down, I don't understand how the cap could have been put on. I think Daryl has a point, namely that you are missing the adapter that acts as a gender changer.

It is hard to describe the class A pipe as male or female because there are both male and female components on each end. The upper and lower unions are essentially an upside down U so the top U goes inside the bottom U. That which goes into the other is generally considered male while that which receives is generally considered female. The inner and outer lips of the upside down U however are the male bits and they point down.

If you google for pics, you will always see them pictured right side up.

(broken link removed to http://www.icc-rsf.com/c/icc/img_db/chem_famille/img_produits_Excel.jpg)
 
He did bring us an adapter along with all new pipes. Thank you again everyone! I truly appreciate your help.
 
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