Black Double Wall Pipe / Screw Length

[djlarson77]

Looking ahead to when I clean my chimney this spring - I want to disassemble the double-wall Excel pipe above the stove. When I removed one of the screws a while back (put in by installer), I noticed that based on the length of the screw, it is possible the screws are penetrating the inside pipe? Do I need to worry about lining up the piping so I use the same screw holes? If not, will the smoke exit those holes? If so, where will it go - does it end up making it inside of the insulated excel piping above?

 

[DAKSY]

You don't want to penetrate the inner wall.
Line the screw holes up if you can, but if you can't,
if you use the holes in the outer diameter, it'll still
work fine & won't look like a cob job...
Unless your cap or chimney are blocked, or it's
REALLY warm outside, there should NOT be any
smoke coming out of anywhere in your connector.
Air will be drawn IN as the chimney drafts.

 

[djlarson77]

You don't want to penetrate the inner wall.
Line the screw holes up if you can, but if you can't,
if you use the holes in the outer diameter, it'll still
work fine & won't look like a cob job...
Unless your cap or chimney are blocked, or it's
REALLY warm outside, there should NOT be any
smoke coming out of anywhere in your connector.
Air will be drawn IN as the chimney drafts.

That's good - that's sorta what I was thinking/hoping but wanted a more experienced opinion or two - thanks!

Seems like using the right size screw would have been the right thing to do - by the contractor. Same contractor who forgot materials to install the inside air kit and blamed it on me for changing my mind several weeks before the install (the invoice he had in hand the day of install showed the inside air kit). He also cut the hole in the floor/ceiling above the stove too far away from the wall, even though I had the correct location marked. If I hadn't been there to correct him, I would have had a pipe 8" further from the wall than it needed to be. I guess it would have been easier for him if I wasn't there watching/helping.....just a little venting, overall he did a good job - he just needed a little guidance/oversight.

 

[daryl]

Looking ahead to when I clean my chimney this spring - I want to disassemble the double-wall Excel pipe above the stove. When I removed one of the screws a while back (put in by installer), I noticed that based on the length of the screw, it is possible the screws are penetrating the inside pipe? Do I need to worry about lining up the piping so I use the same screw holes? If not, will the smoke exit those holes? If so, where will it go - does it end up making it inside of the insulated excel piping above?

The screws supplied with the pipe are a self tapping and do go through the inner liner. So I don't think you have any worries.

 

[Fsappo]

We use 1/2" self tappers on our install. Daksy is right, you can drill a 1" diameter hole in a pipe and if your chimney is working properly, rarely have smoke coming into the room. You'll just be pulling room air into the pipe (which would create a whole different issue) But the size holes your dealing with...line up the outside holes like suggested and you'll be fine.

 

[Wood Heat Stoves]

Looking ahead to when I clean my chimney this spring - I want to disassemble the double-wall Excel pipe above the stove. When I removed one of the screws a while back (put in by installer), I noticed that based on the length of the screw, it is possible the screws are penetrating the inside pipe? Do I need to worry about lining up the piping so I use the same screw holes? If not, will the smoke exit those holes? If so, where will it go - does it end up making it inside of the insulated excel piping above?

The screws supplied with the pipe are a self tapping and do go through the inner liner. So I don't think you have any worries.

nah. the duravent dvl screws only go thru the outer wall, not the stainless inner wall

i think they are about 3/8" +/-