# Relocating vent pipe from kitchen soffit



## Javiles (Dec 12, 2011)

90s fine have an accessible cleanout at the base of the stack, notching beam not a good idea, you may consider an AAV depending on the set up


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## slowmotion (Jul 26, 2015)

I looked into the AAV option you mentioned and AAV's are considered "mechanical vents" in Illinois which are prohibited by Illinois Plumbing Code. I know notching is not ideal, but the joists are in line with the studs so my thought was that the Simpson tie plate would transfer across the top plate.

I've included an additional picture set back a ways to give a better idea of what the situation looks like.


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## rjniles (Feb 5, 2007)

If that is only venting the kitchen sink, it only needs to be 1.5". You can drill that thru the double top plate. If it is larger than 1.5", you can reduce it.


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## slowmotion (Jul 26, 2015)

Yes, it only serves the sink. So I could do the following then?
1. Reduce vertical pipe from 2" to 1.5" diameter
2. Drill 1.5" diameter hole in double top plate (in lieu of cutting a significant notch
3. Install 90 degree bend
4. Expand 1.5" to 2" diameter to meet existing horizontal run


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## rjniles (Feb 5, 2007)

slowmotion said:


> Yes, it only serves the sink. So I could do the following then?
> 1. Reduce vertical pipe from 2" to 1.5" diameter
> 2. Drill 1.5" diameter hole in double top plate (in lieu of cutting a significant notch
> 3. Install 90 degree bend
> 4. Expand 1.5" to 2" diameter to meet existing horizontal run


Yes, except the hole needs to be larger than 1.5". That is the ID of the pipe, you need the OD.


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## djlandkpl (Jan 29, 2013)

slowmotion said:


> 4. Expand 1.5" to 2" diameter to meet existing horizontal run



If you put a reducer on the horizontal run to expand from 1.5 to 2, any water that gets into the vent will get stuck there.


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## slowmotion (Jul 26, 2015)

Good point DJL I had not thought of that. Also the vertical pipe is flush with the face of the stud so I wouldn't be able to drill a hole in the center of the top plate and have everything line up without some type of offset. A drilled hole would need to be large enough to accommodate the bell of the 90 degree bend. I am leaning towards making a ~2.5 inch notch and reinforcing with the strongtie repair plate as shown in the attached image.


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## djlandkpl (Jan 29, 2013)

There should be some wiggle room to get the pipe to the center of the plate. Looking at the pics, is there room above the top plate for an elbow? It looks tight but could be perspective.


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## Yodaman (Mar 9, 2015)

are the new wall cabs. going all the way to the ceiling? I have 39" wall cabs. and still have 6 to 8" of clearance to the ceiling


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## slowmotion (Jul 26, 2015)

Yodaman said:


> are the new wall cabs. going all the way to the ceiling? I have 39" wall cabs. and still have 6 to 8" of clearance to the ceiling


These will be 40" IKEA SEKTION cabinets and the tops will be 1" below the 8' ceiling.


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## Yodaman (Mar 9, 2015)

I have a 8'3'' ceiling, and Ms yoda is a shorty so I sat the wall cabs down 2" from normal height which gives me the 6+ inches above.

Personally I would prefer to drill a hole than notch and use a cover plate. The pipe will push back into the center once you have cut it. (IMO)


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## TheEplumber (Jul 20, 2010)

Your choices are:
Cap the horizontal 2" and extend the vertical piece up and out the roof- add flashing as needed.

Reduce the vent to 1.5" , bury the hub of the 90 in the top plate and the tie back into the 2" and use the structural plate strap. 
Water in the vent should not be an issue- it's a 2" line so pocketed water won't affect the vent because it's over sized.

Verify that no other vent from a basement connects at the kitchen sink- if you have one


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## slowmotion (Jul 26, 2015)

TheEplumber said:


> Your choices are:
> Cap the horizontal 2" and extend the vertical piece up and out the roof- add flashing as needed.
> 
> Reduce the vent to 1.5" , bury the hub of the 90 in the top plate and the tie back into the 2" and use the structural plate strap.
> ...


Just a crawl below so no other lines. If I reduce the vent to 1.5" below the top plate, at what point do I transition back to 2"?


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## TheEplumber (Jul 20, 2010)

slowmotion said:


> Just a crawl below so no other lines. If I reduce the vent to 1.5" below the top plate, at what point do I transition back to 2"?


At or before the next tee

Be sure your inspector excepts those structural plates too


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## rjniles (Feb 5, 2007)

slowmotion said:


> Just a crawl below so no other lines. If I reduce the vent to 1.5" below the top plate, at what point do I transition back to 2"?


If you can access it, I would go back to 2" in the vertical section thru the roof.


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## slowmotion (Jul 26, 2015)

So here is what I ended up doing... I reduced the pipe from 2" to 1.5" and made the 90 degree bend. Glad this was recommended because the 2" bend would have been too large to allow the drywall to extend to the corners - it will be tight enough with the 1.5" bend. I tried to hole saw it and you were correct that there was enough play if I could have drilled the hole in the center of the top plate for that to work, but I just couldn't get it to work. I decided instead to go for the notch and have installed a Simpson plate (not pictured) for reinforcement over the opening after installing the pipe.

Thanks for all the suggestions!


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## jacksplumbingvideos (Nov 23, 2020)

You used pressure fittings on a drain line, that is not code. The old ones where genova dwv elbows from the 1970s.







You need to use new dwv elbows.


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