Sometimes I can find exactly what I want in the IRC, sometimes not.
We’re thinking of putting a woodstove in our shop, on the first floor. The vent will have to travel up thru the floor above, then thru a 12:12 roof. What is the clearance to the roof at the vent terminal?
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Replies
Most chimney pipe makers offer thimbles to go through walls and ceilings. This may or may not answer your questions, but I hope it is at least informative. http://www.discountstove.com/chimney.html
http://www.hansenwholesale.com/fireplaces/stovepipe/chimney.html
Pretty helpful site called hearth.com ( I think that's the name.) Most insulated chimney liners call for a 2 inch clearance. Then the chimney has to stick up 3 feet above the nearest roof surface.
There's a general rule used in wood burning (and other references) called the 3-2-10 rule. It's a minimum though.
- 3' through the roof
- 2' higher than any surface/wall/roof etc within ten feet of the chimney.
Edited 6/17/2006 10:39 am ET by experienced
I was pretty sure about that 2' above anything within 10', and in this case it's going to make for a towering stack of incredibly expensive stainless pipe.... so towering and so expensive that I may not go for it.
Wondering about a direct vent oil stove instead, so that I can burn soybean oil.
That spacing was my requirement also.
I ran my exhaust in black pipe up to exit near the ridge, slopes to get there. Short stainless run after that. Lots of black pipe, but hasn't been replaced, other than the bottom elbows for over a decade. Radiates heat all the way. Don't forget the chicken ladder that lives on the roof, encouraging you to clean periodically.
Unless you really don't want to burn your scraps. It's an interesting way to gain speed. For instance, hand cut dovetails fast enough to keep the stove going.PAHS Designer/Builder- Bury it!
The building has a dormer near where the chimney would be. Now, in thinking about what experienced said, I'm not sure if I simply have to be 3' above any roof, or 10' away from anything other than the roof. The implications are significant, because a stack tall enough to be 10' away from the dormer would be fugly. Maybe I'll get my clothes on and go out there are snap a pic for y'all. My mechanical contractor is coming over Monday to tell me.
Minumum 3' up through the roof you are penetrating.
2' higher than any thing within 10' radius of the chimney. This is inetended to keep the top of the chimney out any area of potential wind downdraft resulting from nearby higher architectural features.
These are minimums and may have to be exceeded in rare occasions.
As exp pointed out, the 10' distance means you don't want it exiting near your dormer walls where they have much height.
Another consideration: I'm always on the lookout for used stainless pipe. Here, often removed with minimal use. Normally I can get by for $3-4/ft. Needed 35' of stainless for my lumber shed lowest level. That part of the design wasn't great. PAHS Designer/Builder- Bury it!
The roof is dominated by the dormers. In the attached pic the proposed vent would exit thru the 12:12 section on the left, near the bottom (woodstove in the corner of the 1st floor area). It looks like the dormer would not be the controlling factor as much as the steepness of the roof. The chimney would have to be 10' tall to be 10' away from the roof. I think we'll do something else, because that will be way too much height to look good... it would be almost comical to me.
Yup, all depends on where you exit the roof. Here's mine. Don't bust a gut laughing at my roofing choice. Y'all were absolutely no help at all (15 yrs ago).
Mine's steeper. And very difficult to photograph with the trees fortunately mostly hiding it. Stove's 10' from a side wall. Pipe follows the roof up.PAHS Designer/Builder- Bury it!
Gut intact. You got off easy going thru at the top. If my chimney were plumb it would exit near the exterior wall. I suppose I could dog-leg it on the second floor, get it closer to the ridge, but that would look quite stupid inside.
Glad you survived. Onduline was only one of my mistakes. I've got 1000 lbs of roll copper surplus from the last roof. Thinking about it.
For me, form follows function. Stupid inside is OK if I stay warm, it's a shop. More pipe inside is warmer. No accident that I got off easy, exiting at the peak.
Speaking of stupid, that's likely the last heated building I'll ever construct above grade. Passive heating/cooling really is better.PAHS Designer/Builder- Bury it!