Ok to screw through outer shell of double wall class a pipe?

[eieioo]

Hi guys,

Noob here trying to get my new wood burning stove installed.

I am trying to install about 20’ of Selkirk supervent class a pipe through an existing brick chase, so I can only support at top and bottom. I did talk to technical support there and they said ok. I am using the additional exterior rings around each joint. I have to build a segment at a time by adding to the bottom

Unfortunately, I have assembled the chimney twice within the chase, but each time I go for the final lift into place, one of the pipe joints in the middle of the run decouples in spite of the outer locking bands being applied as tight as I can get them.

Would it be ok to use some stainless sheet metal screws to also screw the segments together through the outer wall only?

A timely answer would be greatly appreciated as I want to complete tomorrow?

Thanks!

 

[Jackfre]

Well, it is your pipe and their warranty. Sorry, your warranty. I used to represent Selkirk and it has been a while, but they were always sensitive about "how was the pipe installed?" I understand your issue but I would be reluctant to punch holes in the pipe. If you do it make sure that you do not penetrate the inner liner. This can be done but you need to work either from the top or bottom. In your case, the top. Assemble the first joint or two up top. Secure the locking band and make sure you are not turning the joint loose as things progress. I am surprised that you say you can unscrew it even with the locking band tight. You need a "riser clamp" secured below that first joint with the locking band resting on it. A riser clamp is a two piece pipe clamp which will fit around the pipe and the two halves are bolted tight. This done properly will prevent the pipe from slipping. You then have to rig things from above sufficient to support the accumulating weight until you get to the top of the stove. The trick here is to rig this properly. I will say that unless you know what you are doing here, you are living dangerously. Hell, you are living dangerously anyway with this amount of weight. Do not let anyone work from below while this is being assembled and lowered. You go piece by piece and have to be able to handle the weight and secure it as you go piece by piece. I will say that this is an ideal place for a Dura-vent Dura Plus triple wall chimney. I can lift or support 20' of Dura-Plus. At one time I could lift 20' of Selkirk, but then again. "the older I get, the faster I was." Oh, and when you are done you have to reach up inside and remove the riser clamp.

 

[brenndatomu]

I would say no on the screws.
I have put up several Supervent chimneys...the band clamps aren't a foolproof way of keeping things from turning, as you have found out...only turning clockwise (IIRC) pretty much is though. The only time I have had issues with things unscrewing is when trying to remove a creosoted on cap...can be a real problem...helps to be able to put a strong leg grip on that first piece of pipe! That part might be an issue on your setup...one of those pipe clamps mentioned above might be a good idea on the top section (wedged in corner to corner)
But if you decide to screw, use 1/2" stainless steel screws in the outer jacket only, I would think things should be OK since the pipe is in a "brick chase" (old chimney?) I wouldn't do it on an external chimney. Even so, as was mentioned, your warranty will probably be KAPUT, and if there was a chimney related fire, HO insurance would have a way to weasel out of a claim too...

 

[eieioo]

Thank you, folks,

Yes it is a heavy amount of pipe, i would have gone for the triple wall, but there is piece of metal protruding into the chimney and there was not enough clearance.

I don’t thnk that I am unscrewing the pipe, although I suppose that is possible...I think that it is buckling in the middle when I try and lift it up the chase...I need to work from the bottom, because I am about 9feet off the ground level at the bottom and I am trying to push it up as I assemble it...I have a platform at the bottom to work off of...I thought at being 30 ft up, I would prefer not to work off the top!

Yes it is an old chimney that is only lined with cinderblock, and I really don’t want to burn the house down...so I am going to try again without any additional screws. I will only twist rightward.

My wife grew up with regular wood burning for heat, and she really, really wanted (read non negotiable) a particular hearthstone stove! So thanks for helping me !

I looked around for someone to do this job...one wanted to use a flexible stainless liner, but I refused that.

The other one wanted 4K just for the chimney install!

Thank you again.

 

[bholler]

Thank you, folks,

Yes it is a heavy amount of pipe, i would have gone for the triple wall, but there is piece of metal protruding into the chimney and there was not enough clearance.

I don’t thnk that I am unscrewing the pipe, although I suppose that is possible...I think that it is buckling in the middle when I try and lift it up the chase...I need to work from the bottom, because I am about 9feet off the ground level at the bottom and I am trying to push it up as I assemble it...I have a platform at the bottom to work off of...I thought at being 30 ft up, I would prefer not to work off the top!

Yes it is an old chimney that is only lined with cinderblock, and I really don’t want to burn the house down...so I am going to try again without any additional screws. I will only twist rightward.

My wife grew up with regular wood burning for heat, and she really, really wanted (read non negotiable) a particular hearthstone stove! So thanks for helping me !

I looked around for someone to do this job...one wanted to use a flexible stainless liner, but I refused that.

The other one wanted 4K just for the chimney install!

Thank you again.

Why are you putting a chimney inside of a chimney? It is a waste of money and effort. All you should be using is an insulated liner whether it be rigid or flexible.

 

[eieioo]

Thanks to everyone for their response,

The chimney is in! No screws! Nobody died or was injured.

I think the advice to turn right only was helpful.

If you can or could lift 20’ of the double wall, you are the man! That stuff gets heavy.

I talked to the manufacturer (I think that was duravent people)about the liner. They said that is only ok if it is already lined with clay tile, and is not approved for cinderblock...I don’t know if that was just corporate cya, or it really could pose a problem...they said it would not be to code, and I decided not to risk it, and put in a true chimney.

Thank you again to all responders

 

[bholler]

Thanks to everyone for their response,

The chimney is in! No screws! Nobody died or was injured.

I think the advice to turn right only was helpful.

If you can or could lift 20’ of the double wall, you are the man! That stuff gets heavy.

I talked to the manufacturer (I think that was duravent people)about the liner. They said that is only ok if it is already lined with clay tile, and is not approved for cinderblock...I don’t know if that was just corporate cya, or it really could pose a problem...they said it would not be to code, and I decided not to risk it, and put in a true chimney.

Thank you again to all responders

Who ever told you that from duravent was completely clueless. That is what liners are made for they replace clay in many cases. I am glad you got it in but I am curious how you are supporting it? What you are doing is not at all what that chimney was designed for. As long as it is supported properly it will be fine. You just spent much more than you needed to

 

[weatherguy]

Why did you refuse the flexible stainless?

 

[eieioo]

To answer those questions in hopes that this thread can be a resource for somebody else in the future and to hopefully clarify when a liner can be used:

The chimney I was tapping into is over an exterior gas grill... it is built of house brick veneer and cinderblock...there is no true refractory material in the chimney.

I tapped into this chimney from the backside using a through the wall thimble kit, and that is what is supporting below.

on the top I have the mounting brackets tapped into the brick about a foot below the sheet metal cap that the chimney protrudes through.

As I said, when I asked duravent about using a liner, they said it was only approved to line refractory materials that were leaking, and if not refractory materials then I shouldn’t use it...

That is a bummer if I could have really used a liner, but it is in and ready to go at this point.

 

[bholler]

To answer those questions in hopes that this thread can be a resource for somebody else in the future and to hopefully clarify when a liner can be used:

The chimney I was tapping into is over an exterior gas grill... it is built of house brick veneer and cinderblock...there is no true refractory material in the chimney.

I tapped into this chimney from the backside using a through the wall thimble kit, and that is what is supporting below.

on the top I have the mounting brackets tapped into the brick about a foot below the sheet metal cap that the chimney protrudes through.

As I said, when I asked duravent about using a liner, they said it was only approved to line refractory materials that were leaking, and if not refractory materials then I shouldn’t use it...

That is a bummer if I could have really used a liner, but it is in and ready to go at this point.

Yeah you have it done now so it doesn't matter. You did support the bottom as well right? And no you don't need any refractory material at all to use a liner. Just a masonry structure that is a minimum 4" nominal which is actually about 3.5"

 

[begreen]

Yeah you have it done now so it doesn't matter. You did support the bottom as well right? And no you don't need any refractory material at all to use a liner. Just a masonry structure that is a minimum 4" nominal which is actually about 3.5"

The construction of the brick chase is unclear. Not sure if it is brick on all 4 sides and/or a single layer of brick? Or if there are combustibles involved in the construction?

 

[eieioo]

So, i called duravent about the liner because one guy who gave me a bid said liner was ok. But the other guy said not
Ok, has to be a chimney. When I called duravent they were pretty unequivocal that cinderblock(on the two walls shared with the house, and house brick on the other 2 walls wouldn’t be ok with a liner...when I mentioned that back to the guy that originally wanted a liner he back d down and said yeah probably does need a chimney. I’m guessing because no one actually got them selves dirty and truly didn’t more than stick there head under the grill portion of the chimney that they assumed that the chase was built like the rest of the house with wood framing and brick veneer. There are a couple of pieces of 1’ 2x6 lumber stuck under the angle iron where the chimney reduces down to size but they are not structural and I have cut them out.

I am disappointed though because I made it entirely clear to the duravent tekchnical support how the chimney was built and they were pretty unequivocal not to use a liner.

To answer the other question, I have it supported on the triangle support shelf thing under the t on the through the wall assembly. That support part is bolted to the brick, according to Selkirk, that piece is supposed to be able to support 20 or 30 feet of chimney.