Can the chimney go through a wall at an angle?

[farmerchakey]

I've been lurking around the forum for a few weeks and thought I'd run a question by you folks. I bought a Dutch West 2478 earlier this summer and have just set it up last week (BTW I appreciate the videos posted by tradergordo and I noted that this stove does have some complaints on the forum).

I haven't finished off the area around the stove. I'm going to run durock to the ceiling, then we'll probably put up some metal lathe and some faux stone. I've set the stove to the distance specified for an unprotected surface, allowing for an extra 3 inches for finishing the wall. I have two questions. The first is pretty simple - do you normally use some type of cement when fitting the stovepipe together, or do you just slip them together and screw them in place? My second question is related to the photos I attached. My metal chimney goes through a stud wall then up through a closet and out the roof. My concern is when the stove pipe connects to the chimney. It is right next to a block wall, but when I finish off the wall, this connection will be about 2 inches from the faux stone. I know that I could not have any wooden lathe behind the durock in this vicinity. I can still rotate the chimney so that it comes through the wall at an angle giving me more room by the block wall. I read other posts that said up to a 30 degree angle is permissible. I could also use double-wall stove pipe but I suspect that my finished clearance is going to be too close. I estimate around 3 inches. Any comments?

Thank you,
Jay

 

[Brian VT]

I suspect that even with dbl. wall pipe you've got to get away from the outside wall 6". 18" with single wall.

 

[begreen]

Normally no cement is needed at the joints. Just 3 screws, 120 degrees apart.

Is that a standard wall thimble, it looks a bit odd. What is behind that firred in wall that encloses the tee? What are the clearances from the tee and thimble to the wood strips? Are there at least 2" clearances from wood at all points and is this class A pipe?

We'll need to know the pipe for clearances. Is the stove connected with double-wall pipe? If yes, cut out the section of furring strip that is within 6" of the pipe. Don't worry, the durock will bridge the gap. Then you will be ok as long as clearance to combustibles (not the final, stone surface) is 6" or greater.

Edit: On closer inspection that looks like single wall pipe. If so, it won't work.

 

[farmerchakey]

Is that a standard wall thimble, it looks a bit odd. What is behind that firred in wall that encloses the tee? What are the clearances from the tee and thimble to the wood strips? Are there at least 2" clearances from wood at all points and is this class A pipe?

We'll need to know the pipe for clearances. Is the stove connected with double-wall pipe? If yes, cut out the section of furring strip that is within 6" of the pipe. Don't worry, the durock will bridge the gap. Then you will be ok as long as clearance to combustibles (not the final, stone surface) is 6" or greater.

The tee is behind a stud wall (actually in a separate room). Clearances going through that wall are greater than 2". The stove pipe is single wall pipe. I could completely remove the ferring strips on the block wall (to the right in the picture) and use tapcons to put the metal lath on the block wall, but I was hoping to avoid that work. I can rotate the whole chimney so that the tee comes through the stud wall at an angle, giving me more clearance at the ferred block wall.

A local company makes the chimney's using a slightly heavier gauge metal than what I saw in the Amerivent catalog. It is double wall, insulated, 304 (if I recall correctly) stainless steel. Does that answer the class A question?

I trimmed the edge of the thimble because of it's proximity to the block wall. The thimble has a 10" diameter wall in it to provide the 2" clearance around the 8" of the chimney T that passes through it. So I believe the clearance going through the wall is fine.

Thank you,
Jay

 

[begreen]

Sorry, what is showing appears to be an illegal and maybe dangerous installation. The single wall pipe doesn't seem to come close to meet clearance requirements of 18" to combustibles. As for the tee and main flue, what is company and product name? Hard to say whether this is class A pipe or not.

Can you post a picture from the other room of the backside of the pipe? How does this pipe penetrate the floors above it? Are there fire stops and is it chased?

 

[farmerchakey]

Here is a picture from the other side. It is an unfinished room. The tee sits 6" off the wall. I'm going to put some insulation between the wood and thimble.

I'd rather not post the company name. They are a local sheet metal company and they produce chimneys. I'll have to verify with our fire marshall. A shield and firestop exist passing through the attic. I don't have one where it passes into the enclosed space on the first floor but I can still put one on there, which I will do.

To make sure the stove pipe is safe at the wall, should I replace it with double-wall stove pipe or turn the chimney so that I get more clearance from the block wall?

Thank you

 

[Brian VT]

I don't think you're supposed to (allowed to?) insulate around the thimble. The air space is desirable for safety. Leave 12"x12" clear around the thimble.
I don't think double wall will even get you away from the outside wall combustibles enough. I think you need to both turn the tee and use double wall to get the 6" clearance. Maybe you could replace the wood furring with metal stud ? That might help but if I was an insurance person I would be alarmed that the thimble collar
was cut. That right there suggests that clearances have not been met.
Is this pipe all UL listed ? All the clearances we've stated are based on common brands of UL listed pipe.
You gotta think "worst case scenario" here. Your safety 1st and then will insurance cover you if something happened.

Also: It seems that if you turn the tee you'll eliminate one of the 45 elbows. That's a good thing, no ?

 

[begreen]

Sorry, but this setup appears to be using uncertified and untested pipe. There is no way we can be sure about its quality or ability to stand up to wood stove use and temps without proper credentials. Even if it seems ok now, questions about how it will perform over time are unknown.

Also uncertain are the joints, insulation shields, transition adapters to double-wall pipe (that it appears you'll need to connect the stove).

 

[Arlo]

Just my two cents, but your safety is far more important than saving a few $$'s. That set up looks way to inferior to burn wood with. Metal expands, and deforms under extreme temps if pressure is applied to it and that tension strap on the T = failure in the future and possible creasote issues. Do yourself a favor and invest insome Simpson or equivelent stove pipe and chimney. The clearences are nowhere near what they need to be. If the worst does happen, your insurance company would tell you to get bent.

 

[Brian VT]

Another note. If you go through the wall on an angle you'll need to adhere to clearances all the way through.
If it's an approved class A Simpson then you need 12"x12" on both sides of the wall, not just a 12x12 straight through and the pipe angled in that opening.
What I mean is that the thinble will also need to be angled and the 12x12s on either side would be offset from each other. Capiche ?

 

[humpin iron]

that looks like a relining tee, note the hose clamp on the snout. You should spend $$$$$ and have a certified (NFI. org) stove installer come look at this before a disaster happens. If you did a scratch coat over the cinder block and put fake stone on that you would have a completely non-combustible wall and the clearance would not be an issue. The fact that this was not considered and judging by the pics, I believe this may be a DIY project above your capabilities.

 

[farmerchakey]

You folks convinced me. I'm not going to save a few bucks if it puts my family at risk. Since the pipe I had was made of the same materials, I thought I was OK. But I couldn't get anybody to come out and tell me the installation was safe, because the pipe wasn't UL listed. I got a lot of "you should be OK" type of answers, but that wasn't good enough. So...out it came. The local company said that they could reuse most of it. I have replaced it with UL listed pipe matching the specifications of the stove. Shields and firestops are in place.

As far as the original question about going through the wall at an angle - there aren't any prefab parts that support this kind of configuration. So I went straight through the wall. All lath and studs on the block wall have been removed. I'll scratch coat it before applying the stone.

Thank you,
Jay

 

[jtp10181]

Just came across this thread, looks much better now from that angle. The old pipe you had looked like it would be for lining a masonry chimney, not safe to be exposed to studs like that.

 

[Brian VT]

Good to hear. Glad you got it sorted out.
Enjoy the heat !

 

[begreen]

Good to hear Jay. You'll sleep better at night with the right pipe and clearances. And so will I.

 

[pen]

You folks convinced me. I'm not going to save a few bucks if it puts my family at risk. Since the pipe I had was made of the same materials, I thought I was OK. But I couldn't get anybody to come out and tell me the installation was safe, because the pipe wasn't UL listed. I got a lot of "you should be OK" type of answers, but that wasn't good enough. So...out it came. The local company said that they could reuse most of it. I have replaced it with UL listed pipe matching the specifications of the stove. Shields and firestops are in place.

As far as the original question about going through the wall at an angle - there aren't any prefab parts that support this kind of configuration. So I went straight through the wall. All lath and studs on the block wall have been removed. I'll scratch coat it before applying the stone.

Thank you,
Jay

Nice installation!

Now, when you smell something in the middle of the night, and you hop out of bed to check to the stove, you will be doing so out of being obsessive-compulsive regarding safety, because you will know that smell is your neighbor burning ineffeciently, not a problem on your end.

pen

 

[humpin iron]

NICE Sometimes the stuff I see and read on this site scare me. Am glad you took the advice and did the right thing. Yes it was more $$, BUT ITS SAFE