What is wrong with this picture…

[waterbuoy]

You say you run the stove all winter.  Do you open it up at all to burn off the creosote, or does it tend to be 'shut-down' most of the time and smoulder away?

[Guest Gimlet]

Have the liners been fitted upside down? Female ends should be uppermost and the males downward. If it's the other way round the tar will leach out of the joint and run down the outside of the liner rather than running invisibly down the inside and back into the stove. 

Seems odd it should its way onto the outside of the cladding though. You'd expect to see leaching down at the stove connection as well. 

I suspect there's an issue with the terminal and the fitting of the pot, with rain getting in somewhere and carrying soot down the inside of the cladding.

 

I doubt it's down to the wood. Even the most bone-dry kiln logs, like any fuel, will produce soot inside the flue and if that comes into contact with rain water where it shouldn't, you'll get leaching and a sooty mess all over the place. 

Edited March 21, 2023 by Gimlet

[petercb]

That's coming from the very top, you can see where it's running over the edge in front of the chimney pot and then down, looks as if there is some sort of cowl fitted. Looks as if it might be US based, don't know chimney standards they work to over there.

[Guest Gimlet]

7 minutes ago, petercb said:

That's coming from the very top, you can see where it's running over the edge in front of the chimney pot and then down, looks as if there is some sort of cowl fitted. Looks as if it might be US based, don't know chimney standards they work to over there.

That's one of the reasons why brick chimney stacks have corbelled-out terminals. It creates a drip to help stop sooty rain wash running down the stack. 

Now you mention it, I can see the staining along the edge of what I assume is a lead flashing. Having such a flashing instead of mortar flaunching makes things worse as well, as mortar absorbs and holds soot leaching. It's going to run straight off lead.

That terminal needs a redesign. 

 

[organic guy]

13 minutes ago, petercb said:

That's coming from the very top, you can see where it's running over the edge in front of the chimney pot and then down, looks as if there is some sort of cowl fitted. Looks as if it might be US based, don't know chimney standards they work to over there.

It's amazing what you can see if you blow up the picture, there is staining on every board edge top to bottom. You can see where the staining is running off the top of the chimney.

Some kind of issue with the cowl is my guess.

[organic guy]

Just now, organic guy said:

It's amazing what you can see if you blow up the picture, there is staining on every board edge top to bottom. You can see where the staining is running off the top of the chimney.

Some kind of issue with the cowl is my guess.

Gimlett beat me to it!

[Squaredy]

As has been said if you zoom in it is really obvious.  The staining is coming from the very top of the stack.  And if you look at all the "siding" boards (or cladding as we call them) only the bottom of each board is stained, confirming it is simply running down from the top not seeping out part way down the chimney.

 

It would be nice if the OP replied to say if he has had a chance to get someone up a ladder to inspect but clearly something is awry up there. 

 

Seems to me a terrible idea to clad a chimney - it would look far better to be exposed brickwork.  And let's be honest a little tarry residue on brickwork would probably hardly notice, whereas on bright cladding it stands out like a sore thumb.

[Guest Gimlet]

Is there any brickwork under the cladding, or is it just boxing in a metal flue? It barely looks big enough to contain a 13" brick stack, which is what you'd need for flue void with a liner in it.