10-2-3 Rule.... How important? Suggestions Please

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ckdeuce

Feeling the Heat
Hearth Supporter
Feb 11, 2008
264
Western, PA
I have read that the 10-2-3' chimey / roof rule is mainly for wind and drat issues. How important is it? I HAVE to run my chimney through the wall and up the outside of the house. I have a 12/12 pitch roof, and would hate to have 12' of chimney extending past the roof line. It will just look BAD.... I was thinking of just going 6 to 8' above to see if I have issues, but if there is a saftey risk, I will not.

Is this rule more for drafting and wind issue?

Might I be OK with just 6' instead of 12?

Are there any saftey issues?

I am installing a Heartstone Mansfield. 4' of double wall into a wall thimble and 16' of Supervent Chimney.

Thanks
Chris
 
The rule in many cases exists for draft, not just for fire safety.

I have seen MANY chimneys, even on new houses, that do not meet the letter of this code due to adjoining roofs and steep roofs. Still, the taller the better - as you gain height you will gain draft AND eliminate the possibility of wind induced downdrafts.

IMHO, it's more for wind than anything else. And wind is a crap shoot...

Pic shown is a steep roof with nice height chimneys, Maybe this is your house?
 

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Webmaster said:
The rule in many cases exists for draft, not just for fire safety.

I have seen MANY chimneys, even on new houses, that do not meet the letter of this code due to adjoining roofs and steep roofs. Still, the taller the better - as you gain height you will gain draft AND eliminate the possibility of wind induced downdrafts.

IMHO, it's more for wind than anything else. And wind is a crap shoot...

Pic shown is a steep roof with nice height chimneys, Maybe this is your house?

Thanks Craig. That is our vacation cottage, we only spend a few weeks a year there......
 
ckdeuce said:
I HAVE to run my chimney through the wall and up the outside of the house.
Why? Can you rethink the route and chase it up the interior maybe with an offset? The higher up the roof you can exit, the less it looks like a missile silo. Chasing it in all the way to the top and/or putting in a fake dormer instead of just a cricket can help with the look.

A long chimney that runs out a side wall and up can have creosote and draft problems because it doesn't stay warm enough.
 
LLigetfa said:
ckdeuce said:
I HAVE to run my chimney through the wall and up the outside of the house.
Why? Can you rethink the route and chase it up the interior maybe with an offset? The higher up the roof you can exit, the less it looks like a missile silo. Chasing it in all the way to the top and/or putting in a fake dormer instead of just a cricket can help with the look.

A long chimney that runs out a side wall and up can have creosote and draft problems because it doesn't stay warm enough.

I know.... I know... Your just going to have to trust me on this. I was almost crazy yesterday trying to make something else work..... No go. Gotta go out and up. Sucks.
 
Having a similar problem last year this is what I have learned for my Tarm:
Have 12/12 roof on a boiler room attached to garage. The chimney was 8 feet away from garage roof, figured far enough away Ill just put three foot above the boiler room roof and be fine. Wrong answer. Stove didnt draw well, had lots of wind issues with wind coming over garage roof and forcing downdraft into boiler. So in the middle of January last year climbed up ladder onto roof (hate heights) and was able to add a four foot section figuring well that will solve it. (wrong answer again). Definitly helped with the draft. Boiler ran a ton better but downdraft still an issue on windy days and caused burning issues. So just added another three feet of pipe which put me above garage roof line by a little over a foot. About as close as I am gonna get it as I am not putting another section up. AS it stands now I think Ill need a red beacon to alert nearby aircraft :) So I am now where I need to be. I fired for the first time yesterday and no more wind issues. Draft is even better. Stack temps still 400-500 degrees through the burn and it seems to be burning even better. So from my point of view I could have avoided a lot of problems had I followed the rule in the first place. Now just waiting for chimney cleaner to come on Wed for a support bracket to make sure it doesnt tip over. Ill post a pic if i can figure out how to. Good luck
 
The way I see it is the 10' 3' 2' rule is a major clearance to follow ...all codes ...all stoves ...and Class A pipe all state this rule. On a detached storage/workshop building i might fudge it a bit but on my house no way. I have seen Flames shooting out of a chimney with no damage to the house possibly because of the 10'3'2 ' rule.

Just my 2cents

JOhn
 
When I was designing my house, there was much debate WRT to fireplace/chimney placement. Where the wife wanted it, it would have been as you described, a 29 foot (AGL) tall missile with 12 feet of it above the roof. Another factor was cleaning as I insisted on being able to do top down.

Where it is now, I have ~24 feet of overall height (AGL) which is 3 feet lower than the highest roof ridge. It is chased through a walk-in closet. The overall chimney length of approx. 19 feet is shorter than ideal with sometimes marginal draft. If the wind blows the wrong way I need to make sure the upstairs windows are closed but the wind per se doesn't affect the draft. Here is a link to another thread where I posted a pic. As you can see, top down cleaning albeit very infrequent is easy.

https://www.hearth.com/talk/threads/40955/
 

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I would abide by the 10-2-3 rule. And I wouldn't want 12 ft of missle hanging off my house like an albatross. You sure you've exhausted 1. Stove placement 2. Routing chimney thru house with a 45 this a way and a 45 that a way?
 
I have a Hearthstone Mansfield, and a 12 pitch roof on my house. The chimney is about 2' too short, installed by the previous owner, and we have problems getting a decent draft about half of the time we burn. I am going make the chimney the correct height before this years burning season. The chimney will look a little (more) goofy, but I am tired of fighting the stove until it's up to temperature.
 
Webmaster said:
The rule in many cases exists for draft, not just for fire safety.

I have seen MANY chimneys, even on new houses, that do not meet the letter of this code due to adjoining roofs and steep roofs. Still, the taller the better - as you gain height you will gain draft AND eliminate the possibility of wind induced downdrafts.

IMHO, it's more for wind than anything else. And wind is a crap shoot...

Pic shown is a steep roof with nice height chimneys, Maybe this is your house?

I think the cross on the front of the place is a nice touch. Maybe it gets you some divine winds!
 
Draft always matters. The taller the height the draft you get. By this way you eliminate the wind induce downdrafts.




jackscott
_____
(broken link removed)
 
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