Vent Stack in Attic

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ksteen148

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Hello everyone,

Is it okay / does code allow for attaching to the vent stack in the attic? In other words, I don’t think it is practical / possible to tie into the vent stack in the “living space,” the attic would be much easier. I am re-plumbing a master bathroom (shower, sink, separate bathtub, and toilet).

Thanks for your help!
 

MicEd69

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A pure vent, yes. It would be no different that the pipe in the unheated attic.

If a fixture drains into the pipe inside the exterior wall, you might have an issue. If it drains into the line in the basement (not a cellar), then you are probably fine. Or if the wall has 2x6 studs, and the line is not larger than 2", and the line is run next to the drywall with insulation packed between the exterior wall and the pipe, you will also likely be fine.

If the exterior wall has 2x4 studs, I would sister another 2x4 to the studs and make the wall thickness equivalent to a 2x6 stud, or even place the new "sister" stud edge to edge with the existing stud making the wall 7" wide studded.
 

ksteen148

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A pure vent, yes. It would be no different that the pipe in the unheated attic.

If a fixture drains into the pipe inside the exterior wall, you might have an issue. If it drains into the line in the basement (not a cellar), then you are probably fine. Or if the wall has 2x6 studs, and the line is not larger than 2", and the line is run next to the drywall with insulation packed between the exterior wall and the pipe, you will also likely be fine.

If the exterior wall has 2x4 studs, I would sister another 2x4 to the studs and make the wall thickness equivalent to a 2x6 stud, or even place the new "sister" stud edge to edge with the existing stud making the wall 7" wide studded.
This is a huge help! Thank you.
 
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