Advice - Tie into this pipe - How?

[kheflw]

Hi, if I could tie into this vent pipe it would solve one of my problems. Problem is there are no straight pieces.
What you are looking at is a shower trap going to drain with a dry vent coming off and going up. I want to tie into the vent section to vent a vanity.

 

[kheflw]

A better image showing the shower trap

 

[Sponsor]

 

[Highlander]

A flat dry vent is not great (or approved)... where is this vanity sink in relation to what's in the picture? Maybe there's an opportunity to fix the shower vent and connect the sink while you're opening things up.

Edit: not a plumber

 

[kheflw]

Thanks, as I suspected, that flat section of vent was not great, but been there for 40 years or so I guess. The bath and shower that uses it has always drained fine (over the past 5 years I've been here. If you read my other post, I explained that the Bath Tub / Shower combo on the lower floor was plumbed into that drain and I guess the "Plumber" that did it figured it was also a good vent. I know that is not cool.

So to Update:
I've drilled a 2 -1/8" hole in the bay to the right, in line with that the pipe goes up, to the right of the copper supply lines, and there is clear passage to the attic. I can now put in a 1-1/2" directly up to the attic and tie into the dry vent up there for my new vanity. Sounds like a solution.

The only way I see to fix that flat section of vent would be to cut the pipe after the shower trap, and 45 it down about 2 inches, drill a new hole in the joist, and then put a Tee to go down the wall. Then connect a closet 90 to the upper part of the tee to turn up the vent, keeping it all vertical. Might work, I'll think about it.

Thanks

 

[Jadnashua]

It's hard to judge location and elevation from what you posted (at least for me).

BUT, a vent CANNOT go down and be a vent. A vent must only go horizontal, with appropriate slope and max length into consideration before it must go up.

 

[Highlander]

If I understand the other thread as well, you're trying to properly vent a vanity that's on the floor below the shower - if you wanted to hook up to that shower vent you'd have to do it 6" above the flood level of the highest fixture on that vent anyway, not below the floor, so running an independent vent to the attic is probably your best bet.

Not a plumber

 

[kheflw]

Highlander - Agreed. I've already done the same thing on the other side of the new bathroom, ran a new 2 inch pipe to up to the attic and will tie into the 3" Vent through the roof.