Creosote Oozing from Chimney Joint Inside House (Pictures)

[PopulistWoodBurner]

We have creosote running down the outside of our double-wall chimney and inside the house! It is oozing out of a seam where two pieces of the pipe meet in the attic and running down along the pipe. See the two pictures below. Click on the second picture of the larger version to see the seam where the creosote is coming from better. Naturally, I have a few questions about this.

Does this mean my chimney pipe was lapped the wrong way when it was installed? The place we purchased the stove from last fall did the installation too. I read online somewhere that pipes should always be lapped so the creosote runs down the chimney, not out.

Is there any particular immediate danger associated with this? The chimney seems quite sturdy and the joint is tight. I don't even understand how the creosote is getting out.

And finally, how should I fix/stop it?

This is our first year burning wood, so I am still learning. I did sweep the chimney mid-way through the season and got only a small amount of hard, black creosote out. There didn't seem to be sticky, brown creosote on the inside of the pipe. But that is what is coming out of the joint. Thanks so much for the advice!

 

[cmonSTART]

Well, pipe installed upside-down is a possibility. I would look for the UL label on a pipe section. It should have an arrow on it which shows the direction the pipe should be installed.

Next I would check the cap and make sure it's on tight. Maybe it's loose and letting rainwater into the insulated section of the pipe.

It will be interesting to see what you find.

 

[HotCoals]

Looks strange..sure it's not some sort of sealer or something?
I would have them come out and look at it.

 

[PopulistWoodBurner]

I can't see/find the UL sticker on this section of pipe, but the section below and the 45 degree elbow below it are both installed with the UL error pointed up. That would seem to imply the one above it is correct too, assuming they keep going together the same way.

The sticky stuff smells like creosote. I am pretty certain it is that, rather than a sealant or something like that.

Thanks for the advice to far.

 

[gdk84]

This def looks like some sort of water seapage. Is the first photo a shoot from where the stove is located? Tell us about your setup, what brand chimney etc. Also a photo of the outside would be helpful.

 

[begreen]

Agreed. I'd like to see the storm collar on this pipe. Is it properly sealed?

 

[Hogwildz]

I'd check several things:
1. Make sure the storm collar is properly sealed all the way around where it rests against the pipe.
2. Make sure the top is tight and also check the vertical seams on the side of the piping. I seem to remember a couple other members here having issues with rain/water getting in the vertical seams and running down between the piping inner & outer layers, then finding it's way out along the next pipe to pipe seam.
3. Also make sure the base flashing on the roof side is properly installed.

P.S. get that insulation away from the pipe if its contacting the pipe. Should be outside the perimeter of the insulation shield. Or maybe it just looks like it is against the pipe in the photo, but isn't?
Hope there is at least 2" of space between the piping where it goes through the roof planks and the wood planks themselves. If not , you will want to cut more wood out to get the required 2" minimum to combustibles. Again, might just be the photo angle, but looks like it is close or touching.

 

[Fsappo]

I was thinking the same as Hog. It doesnt look like 2" of clearance around that pipe. The inner section of class A pipe should always have the male end facing down. That looks more like creosote than sealer. Best way to tell is the scratch and sniff method. If it smells like creosote, thats probably what it is. I didnt catch if this was a packed pipe or air cooled in the thread.

 

[stoveguy13]

what kind of pipe is that? it kind off looks like a gas vent pipe

 

[PopulistWoodBurner]

Thanks all. I'll go up on the roof to check if everything looks tight and snug. I don't recall seeing any issues up there, but I may not have been looking for them. The pipe is packed/insulated.

If water is getting into the outside layer of the pipe above the roof line, how might it be picking up creosote before it reemerges at the lower joint?

There is 2" of space around the insulation. I see now that the photo angle makes that hard to see. I'll have to double check the clearance to the roofing boards.

 

[begreen]

Just speculating. But the drips may not be coming from the joint. They could be coming from the cap, down the side of the pipe. If the storm collar is not sealed at its top edge with silicone, the drips could be going past it and down the pipe into the attic. As Hog noted, some pipe also benefits from a thin bead of silicone adhesive on the vertical seam of the exterior pipe.

PS: The pipe in the attic needs an insulation shield, especially with blown cellulose floating around up there.

 

[PopulistWoodBurner]

The drips aren't coming all the way from the top on the outside of the pipe. The chimney above the roof line if clean on the outside. If you click on the second picture in my first post, you can see the joint where the creosote is coming from better. It is just below the roof line.

There is an insulation shield, but given how much insulation I have up there, the shield could stand to be a little bit taller. I'll work on that.

 

[begreen]

What brand pipe and what type of cap is on it? How does the pipe interior look from topside if you pull the cap? Might be a section of bad pipe, it should not leak. If all looks in order, I would at least try sealing the vertical exterior seam and any section joint with silicone to see if that addresses the issue or not.

 

[Hogwildz]

Populist....how did you make out with this issue? Curious to know?