Chimney mod... brilliant or stupid?

[johnstra]

I have over 9' of DuraPlus (triple wall insulated inner chamber) sitting on top of my roof - my house is a ranch with a low pitch. I cleaned the chimney last week and it didn't look great. I got a couple of gallons of flaky, crusty creosote. I'm a believer now that double-wall with the thicker insulation layer is better.

I had the thought that I could get some high-temp insulation (i.e. roxul) and fill the outer chamber of the pipe. Would this help? Is it dangerous?

 

[gzecc]

Why do you have 9' sticking out of the roof, code reasons?

 

[SteveKG]

I don't find 9' excessive. I probably have 15' on one stove and 14' on another, 10' on the other, roof surface up to pipe cap. He may need it for draft. Plus, he's in Colorado, air is less dense, a taller chimney can be beneficial.

 

[fossil]

I had the thought that I could get some high-temp insulation (i.e. roxul) and fill the outer chamber of the pipe. Would this help? Is it dangerous?

Pipe wasn't tested & certified in that configuration...you'll void the warranty, and if you ever have a stove-related fire and your modification is discovered, the insurance carrier may decide not to pay out a claim for your loss. Rick

 

[johnstra]

thanks Fossil. Simple answer, huh? Thanks for talking me out of it.

yes, I'm in Colorado with flimsy air and the stove runs way better with mo chimney. I started with 16' total and upped it to 19'. I get longer, cleaner burns with the extra stack height.

 

[stoveguy2esw]

Fossil is correct, never ever modify a UL listed product. as for the stuff you found in the flue , how long did it take to get to that point? how much wood? was it well seasoned? it could simply be normal buildup. woodstoves will leave some residue regardless of if you have a perfect setup. burn too long between cleanings or use less seasoned wood you could get more than normal. BUT the good news is the flaky stuff is less volatile than the gummy stuff.

just keep an eye on it and adjust your cleaning regimen to the rate of buildup. remember there are no 2 identical setups so guidelines are a rough medium, you have to adjust to your own setup and the buildup resulting from it.

keep it clean and safe my friend

 

[johnstra]

It was about two cords over 3 months. This is my first winter in this house with the new BKK and the new chimney. Some of that period was sub-zero so the stove was run in the normal range. Colorado front range, though gets lots of solar gain and relatively warm days thrown in, though, so there were periods when I was running low and slow. I can definitely keep up with the buildup... just brainstorming ways to keep it to a minimum.

 

[stoveguy2esw]

It was about two cords over 3 months. This is my first winter in this house with the new BKK and the new chimney. Some of that period was sub-zero so the stove was run in the normal range. Colorado front range, though gets lots of solar gain and relatively warm days thrown in, though, so there were periods when I was running low and slow. I can definitely keep up with the buildup... just brainstorming ways to keep it to a minimum.

not too terrible , of course with a lot of pre-manufactured (or any) pipe exposed to the elements above the roofline cooling in the top of the flue would be somewhat expected. being flaky its more benign. just remember to configure your cleaning schedule around what you are finding. keep an eye on moisture content of the fuel, if you have a higher degree of moisture its likely you will form deposits at a higher rate than with dryer wood. most of this stuff is common sense. o reason though not to ask though , if anything it gets the information out to more folks.

 

[johnstra]

my wood is very dry... 10-18% MC. I get 3 year old oak from my Dad's place in Louisiana and I buy lodgepole pine. That's one nice thing about CO... you really can buy seasoned wood.

 

[MishMouse]

I thought the Blaze Kings were built to run low and slow to get that extended burn time?

 

[johnstra]

they are... I get 24-36 hour burns routinely. But my 9' of exposed triple-wall chimney cools and flue temps are low anyway. The cat eats most of the bad stuff but apparently not all of it. My stove sat on the showroom floor for several years - it was built in 2008. Next season I'm going re-gasket the cat and check the bypass gasket.

 

[bholler]

Do you actually get any heat off of it for 24-36 hours? Just wondering not being critical.

 

[johnstra]

I do. My house is a 2500 sq ft ranch. If it's 30s to 40s outside, the stove keeps the 1200 sq ft of main living area in the mid 70s for the duration of a 24-36 hour burn. The bedrooms will stay 10 degrees cooler.