Extend flue above masonry chimney

[tomalophicon]

Hi all,

I've recently installed a Pacific Energy insert into a brick fireplace with brick chimney.
I've only got about 12' of flue and would like to try and extend that to around 16' if possible. 

Is there any civilised method for extended flue past the top of a brick chimney that doesn't look terrible, leak water or involve building up the actual chimney itself? I wouldn't mind laying more brick to raise the height of the chimney but don't have the matching bricks.

Thanks!

Tom.

[Edvantage]

I used a piece of stainless round tube and welded a flange on the end that fit over the clay liner with nuts welded on and screws to clamp it in place. It did not work as it ran too cold at the top and formed creosote. Plugged on me twice.  Would post a picture but I just tossed it in the scrap last week. 

[tomalophicon]

Thanks for the reply. Interesting problem regarding the creosote. Worth thinking about.

[Edvantage]

I've burned wood as my only heat source for 20 years. Same stove except for two years I tried a wood cookstove. I extended the chimney for the cookstove, and when I switched back to the lopi stove left the chimney extension. That's when the creosote problem started. Prior to that I have never had to clean the chimney.

[tomalophicon]

Was the extension insulated at all? Wondering if there was insulation it would be a different outcome. 

[tawilson]

 

 
Well, it didn't leak. 

[Don P]

Dry wood, hot fire, warm flue, which is about the dry wood, hot fire, flue length and temperature. If it is quite cold outside insulation will only help, well, if it is warm outside it sure isn't going to do anything but help either. Mine is uninsulated and works in our climate with the way we burn but every setup is different.

[tomalophicon]

Dry wood, hot fire, warm flue, which is about the dry wood, hot fire, flue length and temperature. If it is quite cold outside insulation will only help, well, if it is warm outside it sure isn't going to do anything but help either. Mine is uninsulated and works in our climate with the way we burn but every setup is different.

I have found that even wood at 23-25 is sub optimal in this heater. Anything under 20 and we're good to go - though have never seen anything under 15.
My flue isn't insulated but I don't believe my climate calls for it. 
I do have trouble starting the fire on a cold flue without leaving the door open for around 10 minutes. If I shut it too early I'll get a lot of smoke and smoulder, even with very dry small splits. 
Was thinking a longer flue can only help and PE recommends minimum flue height of 15ft (mine is a bit more than 12ft). 
Ta
Tom.

[tomalophicon]

 
Well, it didn't leak.

Doesn't look bad. Assuming that's a custom job?

[tawilson]

 
Well, it didn't leak.

Doesn't look bad. Assuming that's a custom job?

Yeah I'm a retired tinknocker and slipped that into one of my duct orders. It lasted 15 years or more until I switched from oil to propane. If it was for wood burning I guess you could just stop at the square to round and go to insulated pipe.

[tomalophicon]

 
Well, it didn't leak.

Doesn't look bad. Assuming that's a custom job?

Yeah I'm a retired tinknocker and slipped that into one of my duct orders. It lasted 15 years or more until I switched from oil to propane. If it was for wood burning I guess you could just stop at the square to round and go to insulated pipe.

Thanks! food for thought.

[tomalophicon]

Following up with a pic.
I simply purchased a triple skin kit of 3ft and installed it all into the existing single 6" pipe. Figured there might be a little insulation with the extra tubes.
Draught has improved considerably. 
Tom.