Double wall stove pipe (Selkirk) questions...

[brenndatomu]

My in-laws are building a new house and are installing a new Englander NC30 stove, easy enough so far right?
Somehow I have been put in charge of this part of the project since dad knows nothing about proper chimneys, etc. I will be installing a Supervent class A chimney straight up through the roof...still pretty straight forward. Where things take a turn here is that dad went and built the chimney chase without consulting with me about its specific location.
The stove is going in the corner of the living room at a 45* angle on a built up hearth. I wanted the chimney directly above the stove so we could just go straight up, but dad put it right in the corner of the room. So now the stovepipe will need to have a little offset to it (18-20") in about 4' of rise. Also, we will have to use double wall stovepipe because now it will be within 10-12" of the wall by the time it connects to the chimney.
I have been using Selkirks offset chart to try to figure out what exactly to order...then I noticed this phrase on the description of the 45* elbow "Non-positional connection system allows 360 ° rotation".
What exactly does that mean? Does that mean it is basically an adjustable elbow? If so that simplify's things a lot...
That would mean my parts list would be whittled down to (2) 45 elbows and (1) telescoping pipe and (1) stove adapter.

 

[Highbeam]

I think it just means that you can rotate the 45. You still need the length of pipe between the 45s. Plus the single length to the stove.

 

[Karl Hungus]

Highbeam is right, you can rotate the angle pc once its on so that the angle goes where you want.
I just did 2 duravent chimneys, one with a 30 deg and one with a 15 degree. Did some reading and I don't remember where I read it but it said 30 degree is the most you want to go on a chimney angle. the less angle the better.

 

[Karl Hungus]

Just for clarification are you talking stove pipe or class A chimney pipe?

 

[brenndatomu]

Stove pipe, not class A chimney pipe.
So the effective angle can be changed? Like a 45* can be adjusted into a 25* just for example. (like the cheap single wall adjustable elbows) I've always thought double wall was normally non adjustable angle wise...I have a feeling this actually is the case here...when they refer to "rotating", they mean you can "turn it around on the pipe" which I don't understand why they list that as a feature...I mean if you have an elbow that locks onto the pipe, can't you then just turn the pipe to a workable spot?
Their wording on this is clear as mud IMO...

 

[begreen]

For Technical Service - 1.800.748.0392 (press option 5)

 

[Highbeam]

Stove pipe, not class A chimney pipe.
So the effective angle can be changed? Like a 45* can be adjusted into a 25* just for example. (like the cheap single wall adjustable elbows) I've always thought double wall was normally non adjustable angle wise...I have a feeling this actually is the case here...when they refer to "rotating", they mean you can "turn it around on the pipe" which I don't understand why they list that as a feature...I mean if you have an elbow that locks onto the pipe, can't you then just turn the pipe to a workable spot?
Their wording on this is clear as mud IMO...

45 is a 45. With most double wall pieces the screw holes are prepunched so they can't be rotated. Sounds like the feature of these 45s is that the holes are not punched.

 

[begreen]

I just spoke with an engineer at Selkirk and the clarification I got was that this is just marketing speak. The joints of the 45 are not adjustable, but you can rotate the position of the elbow until it is attached to the next piece.

Even if the holes on the non-crimped end are prepunched, the crimped end are not. You need to either predrill those holes or use self-tappers. Up to the point of screwing it together one can rotate the position at will, then drill or self-tap in that position.

 

[brenndatomu]

Yeah I stopped at Menards and looked at 'em today...definitely not adjustable, the sections are tack welded together inside. Thanks for the responses guys!
Guess I'm back to getting the right combination of adjustable and fixed pipe lengths to go with the (2) 45*s...and a lil brushing up on the ole geometry. I really don't find their run/rise chart very helpful.

 

[Sconnie Burner]

Yeah I stopped at Menards and looked at 'em today...definitely not adjustable, the sections are tack welded together inside. Thanks for the responses guys!
Guess I'm back to getting the right combination of adjustable and fixed pipe lengths to go with the (2) 45*s...and a lil brushing up on the ole geometry. I really don't find their run/rise chart very helpful.

Look into DuraVent (found it at my local farm store, Fleet Farm). I ordered 2 double wall 45s (unavailable at my stores) online and they are adjustable on the angles like the old single wall ones. I don't need to move them for my install but playing around with them I did notice that the individual sections do pivot to change the angle. Not sure exactly how far though.
6DVL‑E45 is the part #
Here is where I ordered from:
https://www.hardwareworld.com/p9w79c6/Elbow-45-Degree-Double-Wall-Black-6

 

[rwhite]

If you are going straight up then over you need 90 degrees no matter how you get there. Otherwise the pipe is not going to sit flush on one of the connections. So if you adjust one section to increase length the other section has to be adjusted to get your 90 and it will shorten, putting you right back to the same run length as you started with. Place the stove where it is exact on all clearances. Find the center of your support box and measure that distance off the truss and drive a screw in the ceiling to hang a plumb bob off. Move the screw left or right until the Center Of the stove collar, plumb, and corner all line up. Measure from the stove collar center to the plumb to get your run. Just go down the column for the diameter of pipe you using to get the proper run length then over to the right to see what length of section you need . I recommend marking your stove legs with a sharpie once you have it where you want because it's likely you'll have to move it to get a ladder in there. Makes getting it back in the same spot easier. I also recommend the use of a telescoping section so you can raise it up and down to meet the elbows properly.

 

[Highbeam]

The way I read the op is that this is an offset to the ceiling support box that was placed 18" farther into the corner than it should have been for an all vertical install. Not an up and over through the wall.

If so, then the angles of the elbows just need to match. Varying the angle would vary the length of the slanted piece between them. Instead, with fixed 45s you must either move the stove or use two adjustable lengths for the interior pipe.

 

[brenndatomu]

The way I read the op is that this is an offset to the ceiling support box that was placed 18" farther into the corner than it should have been for an all vertical install. Not an up and over through the wall.

Yes, exactly.
It was supposed to be a simple straight up chimney, directly above the stove. I was thinking we'd just cut a hole in the roof when it was time, but I didn't realize they wanted a chase around the pipe and dad went ahead and built the chimney chase above the "corner of the room" before I got there to lay things out.
So now the pipe will go straight up, 45 over, and then another 45 at the chimney adapter.

I was out there today and remeasured, then I went and bought all the chimney parts that I think we need.
It measures out as follows, the offset is actually 23.5" and I need about 46" of pipe height between the top of the NC 30 and the bottom of the class A (actually the chimney adapter) due to the raised hearth that she'll be sitting on.
Now if you look at their offset chart, (1) section of 24" pipe will get me 22.75" offset. I can actually reduce the amount of offset that I need by 1/2" by moving the center line of the chimney 1/2" (which will put the CTC at the 2" minimum) so that leaves me a 1/4" short...I can probably "fudge" the DSP stovepipe that much...or scooch the stove back a hair and fudge the pipe a hair. That brings up another question, when ESW says you need 15" from the rear corners of the stove, are they talking from the corners of the rear heat shield, or the corners of the actual firebox? Inch or 2 difference there...

 

[Highbeam]

I would fudge 1/4" but remember that you can get a telescoping chunk between the 45s and another elescoping chunk between the stove and a 45. Then put it all together, plumb her up, and pin the slipjoints.

Not sure where the measurement is taken but I would assume the stove body and not the edge of the top plate.

 

[brenndatomu]

I think this will all work out just fine with the 24" section between the 45s...I can move the stove back another 1/2". I originally measured 15.5" out from the studs to account for the drywall. But it turns out instead of drywall they are putting Durock up on the walls behind the hearth...and then "drystack" stone on the walls...so between moving the chimney a bit, and moving the stove a bit, we are good to go!
And yeah, I'll be using 1 adjustable pipe and 1 stove adapter in the vertical section, gonna work out juuust right...