Can I make a horizontal run of Class A before a Tee?

[shub]

I am trying to design a code acceptable way of getting a Class A chimney out the back of my roof and lined up on the same plane as my masonry chimney, so I can later put a chase around it and have them look symmetrical.

I made a scale model of the profile of my home, and my idea.

Basically I want to run the chimney from my living room on the front of my ranch house, out the back of the house. The 30 degree offsets will not allow this without running straight up from the other side of the attic carrying beam. Can I install a Wall thimble, then from the thimble, run a horizontal run of Class A chimney pipe through the basement stairwell over to a Tee. In other words can I make the Tee an effective 90 degree elbow about 3 feet from the thimble or does the Tee by code need to be connected directly to the thimble?

Also... Once I get the chimney out the roof, does it need to be 10 feet away from the other chimney if I want it to be the same height as the masonry chimney?

 

[begreen]

It looks like a recipe for poor draft with the long horizontal. I don't know the specific rule here, but in this case I would say the tee is acting as a 90 deg elbow which is not permitted on class A.

 

[mikefrommaine]

I believe supervent allows a 24" max horizontal run before the tee. Other brands may be different.

 

[shub]

Okay, 24" would be better than nothing. Is it possible to do a 15 degree offset out of the thimble before the tee to pitch the run a bit?

 

[woodmiser]

I think BG is correct. Class A is not designed to take heat in a horizontal direction. I would say no way. I doubt if any class A manufacturers even lay it sideways in testing.

 

[ScotO]

yeah I have to agree with the others on this one, hands down....esp. having that long horizontal run coming right out of that stove where the gasses are their hottest, that is a bad bad idea......why not go more-or-less straight up?........you will reap large benefits from both the draft aspect AND the cleaning aspect......and class A, IMHO, looks good installed through the roof......nice clean look......

 

[shub]

Thanks for the advice guys, I freely admit I am green and ignorant on the subject of chimneys. As a new member to the forum I am pleased to see how readily you guys lend advice. I hope to get a stove installed this month, and become a frequent poster. I've only spent a couple weeks seriously considering having an installation performed, so I'm learning as I go. The reason I wanted to route the chimney out the back is because I have some minor OCD, and right now there's nothing protruding from the roof of my house street side. But in the back, there's a chimney and a few vent pipes, so it wouldn't really bother me to have another thing sticking out of the roof. If I go out the street side of my roof the stainless steel pipe will feel like an eye sore to me and increase my desire to get it chased out in brick sooner (which is sort of out of budget in the short term)

Does anybody have any creative suggestions for how I can still get it out the back? The drawing is to scale. The home is 24' wide and 38' long. 7.5 feet to the ceiling, 4ft in the attic.

 

[mikefrommaine]

It will be a much better and less expensive install if you go straight up.

However the instructions that come with the supervent through the wall kit allow for a maximum 24" horizontal section of class a. It must protrude through the wall 3"

 

[shub]

Okay.

Well, I am not sure what brand of pipe the installer is using. He quoted $2,500 (parts & labor) for a straight up through install, which I may end up having to do. He wants $500 more for each offset I want to add. I'll ask him what he's using, but it sounds like having the Tee that far away from the thimble will be a bad idea anyway. I'll keep messing around with the drawing to see if I can come up with an alternative. At the moment, I am wondering what will happen if I do a through the wall thimble like I originally intended, but then immediately have the Tee on the opposite wall, followed by a 30 degree elbow coming out of the tee, delivering a length of pipe to the attic diagonally. Are there support boxes that will take a pipe entering at 30 degrees? I think that would roughly line it up with my other chimney.

On a separate note though, is my other chimney considered an "obstruction" when figuring for the 10 foot radius? Even the straight through the roof installation will have the chimney 8 feet from the other chimney. If I need to go two feet higher than the other chimney that would put it about 6 feet tall, which would require bracing if I understand right. That would also offend my OCD a bit... If I end up chasing out a chimney though, will that suffice as a brace?

 

[Backwoods Savage]

Welcome to the forum shub.

In addition to the advice above, you should take into consideration what will happen when it comes time to clean the chimney. That diagram looks like it would really cause some problems that you would not want to tackle.

As for the horizontal, we do run horizontal from the stove and use a Tee. However, our pipe runs through the outside wall (with about 1/2" rise per foot of horizontal. 1/4" rise is to code.) and into a tee. Then it goes straight up the outside of the house. Yes, this is a bit expensive but it works rather nice. Also, realize that for every bend in the pipe you are effectively reducing the total height of the chimney. Generally you can figure for every 90 degree bend you are reducing by 2-3'. So if your chimney is 15' high and you have 2 elbows, your chimney is then effectively from 9' to 11' for draft purposes. Most stoves want 13' - 15' minimum.

 

[mikefrommaine]

Fwiw 2500 seems high for a straight up chimney/install.

I don't see more than 750 in materials and 8 hours labor. Unless there is rafters and joists that need to be moved, which is unlikely based on your diagram, I would look for a contractor that is a little more reasonable.

 

[Vincent]

I have a 2 or 3 foot section before my tee. I built a dummy wall for water pipe shut off when i finished my basement. My leads to a outside tee and runs up side of house and though the eave. I had a professional installer do the job. I never have a draft problem, but I always open a nearby window just to make sure.

 

[ScotO]

Fwiw 2500 seems high for a straight up chimney/install.

I don't see more than 750 in materials and 8 hours labor. Unless there is rafters and joists that need to be moved, which is unlikely based on your diagram, I would look for a contractor that is a little more reasonable.

I agree......so shop around, you should be able to find a better deal than that, although you are gettin near the season when they can kinda dictate the price, esp. if you want it done before winter.....