Is it ok that I did a sink drain this way before I close up with drywall?

[Thekid1]

As you can see, I have a 2" sink drain here. I didn't think much about it until now. Will this drain work properly since I came into the drain pipe horizontally with a sanitary tee?

It drains to the left and pitched ¼" per foot. The verticle pipe to the right a is 2" dry vent that eventually pipes into the 3" main stack along with other fixtures.

 

[wwhitney]

The main problem you have is that a dry vent can't be horizontal until at least 6" above the fixture flood rim. Also you are correct, a san-tee can't be used for drainage in that configuration, it should be a combo.

Hopefully your cabinet layout will accommodate moving the sink stub out a bit to the right. Then you can have a street LT90 sticking out of the wall, with the street outlet horizontal behind the wall. It can hit an immediate wye, with the barrel horizontal and the side branch upright, for your dry vent. The dry vent can then rise at a 45 degree angle, missing the window and connecting to your true vertical dry vent. [45 degrees off plumb counts as vertical for the plumbing code.]

Cheers, Wayne

 

[Sponsor]

 

[Thekid1]

The main problem you have is that a dry vent can't be horizontal until at least 6" above the fixture flood rim. Also you are correct, a san-tee can't be used for drainage in that configuration, it should be a combo.

Hopefully your cabinet layout will accommodate moving the sink stub out a bit to the right. Then you can have a street LT90 sticking out of the wall, with the street outlet horizontal behind the wall. It can hit an immediate wye, with the barrel horizontal and the side branch upright, for your dry vent. The dry vent can then rise at a 45 degree angle, missing the window and connecting to your true vertical dry vent. [45 degrees off plumb counts as vertical for the plumbing code.]

Cheers, Wayne

I think this is what you are saying?

 

[wwhitney]

Ah, my answer was based on the assumption the window sill was 42" or below, so that you couldn't go horizontal under the window. But with the window sill at 48", that makes it easier.

I marked up your drawing below. The drawing doesn't quite work as the segment in red is still a horizontal dry vent below the 42" elevation. So delete the red and orange segments, and add the green segment. That means instead of the combo-wye, you'll have a LT90 going to an upright wye.

As you don't need to get out from under the window before turning horizontal, there's no rush to start the vent and you don't need to use a street LT90 directly into the wye. But you still can do it that way if you like.

Cheers, Wayne

 

[Thekid1]

Thanks Wayne. I updated my drawing I guess before you commented the second time.

So I'm 100% clear on the immediate venting to clear the window.

Now that we know it is 48" sill, I just want to be clear of the configuration it should be if I don't do the 45° vent. Can you draw that please?

 

[wwhitney]

Your updated drawing in post #3 is what you need to do if the window sill is low enough that you aren't allowed to go horizontal under the sill. [Except it's not called a combo, it's a wye.]

If your window sill is high enough that you can go horizontal under the window sill, then your vent can either rise up at 45 degrees (stick with a wye on the horizontal drain) or at true vertical (use an actual combo on the horizontal drain; IPC would allow a san-tee on its back for this purpose but a combo is better). Then once you are high enough, turn horizontal with a 45 or 90, respectively.

Cheers, Wayne

 

[Thekid1]

Your updated drawing in post #3 is what you need to do if the window sill is low enough that you aren't allowed to go horizontal under the sill. [Except it's not called a combo, it's a wye.]

If your window sill is high enough that you can go horizontal under the window sill, then your vent can either rise up at 45 degrees (stick with a wye on the horizontal drain) or at true vertical (use an actual combo on the horizontal drain; IPC would allow a san-tee on its back for this purpose but a combo is better). Then once you are high enough, turn horizontal with a 45 or 90, respectively.

Cheers, Wayne

I appreciate that. So if I go the horizontal route, I believe you are explaining this:

 

[wwhitney]

Yes, that works. But the layout in post 4 (where orange and red are deleted) also works. Either way.

Cheers, Wayne

 

[Thekid1]

Nice. Thank you for your time, help, and patience.

John

 

[Reach4]

Change '6" above floor' to '6" above the flood level of the sink'. FLR looks too much like floor.

 

[Thekid1]

Change '6" above floor' to '6" above the flood level of the sink'. FLR looks too much like floor.

That's true. Didn't think of that.