Can vent dip down a small amount?

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iamkevinc

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Hi,
I'm putting in a new bathroom on a second floor. There was no bathroom on the 2nd floor previously and the roof has a barn style roof line. The vent is going through the roof not near the center and at a point which is is lower than the ceiling height of the middle of the room. I am wanting to put a sink in across from the room from where the main vent is (maybe 5 feet) but i cant get a straight path from the new sink vent to the main vent without running the vent up into the small attic area and then dipping down back into the main vent stack. I'm going to try to install a picture which is not to scale to get the idea across.

I dont think the dip is ideal.... but my question is ...is it wrong or against code? since it is well above any drain the only possible concern would seem to be which direction condensation might drip down, but either direction is down.

Thanks for any help!
vent.jpg
 
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NHmaster

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the short answer is no. the long answer is that the vent must rise with pitch toward the drain.
 

hj

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From your drawing it is NOT a small amount. By code, an inspector would probably reject it, although functionally it would work. A bigger question, since this may not be going to be inspected is WHAT pipe did you connect into for your new bathroom? I hope not the pipe coming up from the lower bathroom, because if you did that, the route of this vent is the least of your problems.
 

iamkevinc

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There are no fixtures lower in the stack. It's a very old house(1908) but no collectors item. The actual dip/drop is like one foot down and would take a foot and a half pipe to get there at 45 degrees.
 

Krow

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It will work as long as the condensation that may accumulate in the vent pipe has some place to drain, whether it be towards the fixtures or back to the main stack.

Is it code compliant in your state? probably not

In Canada it is a gray area as long as its a very short distance down back to the main vent (Not all Canadian inspectors will recognize back fall on a vent code compliant) there is room for argument with inspectors about it
 

Dlarrivee

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Why don't you just go out the roof with the vent that you're installing?

I don't understand why you think you need to connect it to an existing vent stack.
 

iamkevinc

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i've considered that. it's just a really high roof with significant slope and i dont have a 30 foot ladder.
 

Dlarrivee

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So the reason for not doing something correctly is that you don't own a ladder?

I can rent the ladder you need for $15 from the rental place 5 minutes away...
 

Rich B

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I had to do some roof additions myself...... I Hired a roofer to do the work. The peak of my 2 story house is probably 25 feet up. The roofer went right up to the peak with his ladder and did it numerous times. Installed some bathroom vents for fans and I had him add a plumbing vent that I could connect up to in the attic..... I can understand someone not wanting to climb a ladder no matter how cheap they are to rent. I used to go up on my roof by using a ladder off an addition. I am not comfortable on ladders and won't do it anymore.....Hire someone to do the roof work and install another vent thru the roof straight up.....Have him flash it properly and you can connect it up inside safely......I still haven't connected up the vent I had installed as the inside plumbing is not finished. I have it capped and can pop the cap off from inside with a broom handle once I am ready to finsih it.......
 

Dlarrivee

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Telling him to hire someone else to do the work doesn't answer the question.

By code, pretty much anywhere, the answer is no. The vent should slope towards the drain it is serving.

The proper way of doing this is to exit through the roof with the vent.

If you don't want to use a ladder, or tools, or do any work, then just hire someone... That's pretty obvious and doesn't really help any.
 

Rich B

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My advice was to hire someone to add a new vent straight up and out the roof with the flashing. My intent was for him to do it properly but have someone else do the roof work....That is exactly what I had done......
 

Rich B

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HJ can you give some more info about that flashing that installs on the inside......I'd like to see what it looks like....
 
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