Offset flue or straight up?

[nshif]

Im close to installing a Quad 4300 in a new const home. The stove will sit in a corner near the lowest wall which is 16' high. The roof has an 8/12 pitch which means I need at least 10 - 12 feet above that to meet the 10/2 rule. The stove will sit on a 16" hearth so the distance to the ceiling would be about 12'. So im guessing about 22 -24' overall.
My concern is with the snow sliding off the roof tearing the chiminey down. Its a metal roof on an 8/12 pitch and will build up to about 18" before it leats go. And when it does its like an avalanche. Sometimes I fear for my dogs lives if caught under it.
I realize I could build a chase around it but that seems rather a pain and wont look so good.
My other thought is to exit the wall at about 12' with a 90, out 2' to clear the overhang then up the remainder.
I guess my only question is do you think this will hamper my draft adversly?

 

[jtp10181]

If you get at least one set of roof support brackets and use joint clamps on all the exposed joints you should be good. There are usually quite a few other little things you can get to add extra support depending on the chimney version you are using. Take a look at the catalog and see what they have for adding extra stability.

 

[nshif]

JTP
Im useing Simpson Duravent, and Ive looked at the support options but Im not sure I trust them. Plus Im 3' from 2 eves so Im limited in my anchor options. We get very heavy WET snow at this elev. And when it comes down its like a D8 Cat. Ive seen gutters ripped off, deck rails knocked over and even a patio roof caved in. If Im not going to suffer alot of draft problems from the 3' of horizontal run and 2 90s then it isnt worth it, I just thought that putting it out in the open might be better. ( and perhaps cheaper, Id only need a wall thimble and 2 90s instead of a ceiling box and a roof seal.

 

[Shane]

Either way your at the bottom and that chimney is going ot get whacked. I would suggest some sort of snow diverter built into the roof. Angle iron or other means of breaking the snow and diverting much of it. Keeping the chimney straight if you can is advisable, as horizontal runs always affect draft.

 

[nshif]

I dont think its going to get wacked if Im on the outside of the roof line on the angle side, not on the downhill side. I realize I will compromise my draft but with that kind of height will it be significant?

 

[Gooserider]

Well, your best draft will be if you go straight up, so I think the optimal solution would be to build a "frog" on the roof to divert the snow (perhaps multiple frogs in a series?) but that might not be possible.

Given that you are looking at a fairly tall chimney, I think you probably could get away with the jog approach, but it will definitely hurt your draft - a 90* elbow is considered to be the same as shortening the stack by 5 feet, so your efffective length would go from 22-24' to 12-14', or almost cutting the stack height in half, and possibly going below the reccomended minimum stack for your stove (especially since Tahoe is fairly high altitude, and minimum stack goes up as you get higher...) Cleaning the pipe will also be a real pain as it is not easy to get the brush to go around a 90.

One thing that might be possible (I'm not sure, as I don't know if the hardware is available - do they make 45* wall pass through boxes???) would be to use two 45* angle bends instead of 90's, and a longer transition peice running at an angle. That would give you only one 90* in effect, so you would have less impact on the draft. It would also be easier to clean.

Gooserider

 

[begreen]

Double brace it if necessary, but I'd prefer straight up if possible. There was a thread a while ago that showed some stout bracing, Alaska style. That oughta do her.

 

[nshif]

Goose
I thought of 45s but Ive had no luck in finding a 45 wall thimble. Min height from Quad is 14 - 16' so Id be right on the edge. I just got out my blue prints and did some more presise measuring and looks like stack height is more like 25- 26'. My elev. is not as high as Tahoe Im just above 4000'. Quad doesnt recomend any offsets above 4000' . So looks like to be on the safe side Id better go straight up and build a chase with a cricket. or brace the tar out of it as BG said.

 

[Hogwildz]

Why dont you just put snow stops on the roof panels above the chimney?

 

[nshif]

Hog
Thats was I was refering to as crickets. Not the wooden type used on flat roofs but prefab metal ones screwed or lagged to the metal roof.