Kitchen drain/vent routing ideas

[Dmt78]

Sorry for all the questions, but this forum has been very helpful.
I need to bring the vent for this kitchen sink to the right of this window. All my vents are 2”, but I could reduce down this portion to pass through the 2x4 studs or there is a 8” metal purlin directly behind the 4 studs on the right that I may be able to drill through. I’m leaning towards rolling back with a 22 degree then drilling through the metal purlin/girt and then rolling back forward with another 22 once inside the next stud bay. Should I drill/notch all the studs or try going through the purlin? Any suggestions?
I will be cutting this stub shorter btw. code is IPC.

 

[Terry]

Venting on a kitchen sink is 1.5"
A hole that works for that is 2-1/8",
2-1/4" if it needs to be large enough for the fitting to be inside the hole.

 

[Sponsor]

 

[wwhitney]

Is the wood stud wall load bearing? There seems to be a metal structure behind it on the exterior.

If the wood stud wall is not load bearing, just drill all the studs dead center. If it is load bearing, you could consider moving the stud to the right of the king stud, still going through the king/jack/cripple, and using a Simpson HSS2-3-SDS3 to reinforce that.

Cheers, Wayne

 

[Dmt78]

Venting on a kitchen sink is 1.5"
A hole that works for that is 2-1/8",
2-1/4" if it needs to be large enough for the fitting to be inside the hole.

Hi Terry, so going to the 1 1/2” and drilling through the studs then connecting back to the 2” main vent is my best bet? Thanks for the advice.

 

[Dmt78]

Is the wood stud wall load bearing? There seems to be a metal structure behind it on the exterior.

If the wood stud wall is not load bearing, just drill all the studs dead center. If it is load bearing, you could consider moving the stud to the right of the king stud, still going through the king/jack/cripple, and using a Simpson HSS2-3-SDS3 to reinforce that.

Cheers, Wayne

The steel building is supported on its own, so nothing inside is really load bearing, other than a small second floor loft across the house. Drilling through the studs would be much easier. Thanks

 

[wwhitney]

The steel building is supported on its own, so nothing inside is really load bearing, other than a small second floor loft across the house.

If that kitchen wall is supporting the second floor loft, that I would suggest using the Simpson HSS2-3-SDS3.

Cheers, Wayne

 

[Dmt78]

If that kitchen wall is supporting the second floor loft, that I would suggest using the Simpson HSS2-3-SDS3.

Cheers, Wayne

It’s not supporting the loft. The loft is on the other side of the house.

 

[Jeff H Young]

I haven't worked with metal buildings but it appears no need to go through the studs? if not bearing anything shouldn't hurt to drill if you find it easier

 

[wwhitney]

I’m leaning towards rolling back with a 22 degree then drilling through the metal purlin/girt and then rolling back forward with another 22 once inside the next stud bay. Should I drill/notch all the studs or try going through the purlin? Any suggestions?

So what is elevation of the girt relative to your final counter top height? One of the restrictions is that a horizontal dry vent needs to be 6" above the fixture flood rim, which is generally the countertop for a kitchen sink. Unless your plumbing code has an exception for structural conditions precluding that, which in the US the UPC does but the IPC doesn't.

If the girt were 12" above the counter, you could rise to 6" above the counter, turn horizontal pointed at 22.5 degrees relative to perpendicular to the studs, jog behind the studs, hit a 22.5, then pass under the girt, hit another 22.5 and 90 to jog back into the stud bay and back to vertical. This assumes the girt is deep enough for the vent to fit between the studs and whatever the girt is supporting.

But presumably the girt is lower than that, so you'd either have to go through the studs at a 45, go through the girt at a 45, or go horizontal lower than 6" above the flood rim (in which case you could still jog around the studs under the girt), or use an AAV.

Cheers, Wayne

 

[Dmt78]

The girt is at 40” from floor. So according to 2012 IPC I can’t turn horizontal before reach 6” above sink rim correct?
So best bet would be to cut the drain stub up lower and go 45 degrees through studs and turn up to the right side of the next bay? The sink is under mount if that makes a little difference.

 

[Jeff H Young]

technically 6 inches above flood level so if the sink is undermounted it would be counter top height. kind of splitting hairs but meeting code sometimes is.
sometimes you can offset the vent on a 45 its Legal before going horizontal at the minimum. a little tip that might help

 

[Dmt78]

Hey guys, one last question on this. Would it be up to code (IPC 2012) to use a 60 degree fitting to go up through the studs to instead of 45 degree? I know the code doesn’t seem to say specifically.

 

[wwhitney]

If you mean turn 60 degrees from plumb, 30 degrees above level, that's generally considered horizontal.

But I think your best solution is to duck behind the studs for the horizontal traverse, and back out into the stud bay to go past the metal girt. Starting at the wood plate and going upward, the following would keep you at 45 degrees off plumb at each elbow:

Vertical stub up
45 elbow with inlet pointed towards wall
60 elbow with inlet pointed to the right
Pipe behind studs
60 elbow with inlet pointed away form wall
45 elbow with inlet pointed straight up

That doesn't specify where the san-tee for your sink trap arm is located. It can go in either of the straight pipe sections: either on the vertical on the riser coming out of the slab, or on the pipe segment behind the studs that is rising at a 45 degree angle. In the later case the trap arm would stub out in the stud bay next to the triple stud.

The picture below attempts to show the above, with the san-tee represented by a circle, but I can't really draw the double elbow bends accurately.

Cheers, Wayne

 

[Reach4]

Another alternative with two horizontals, which could be easier, but if you are not drilling, probably not easier.....

Lower right 90 is long sweep.

 

[Dmt78]

Here’s what I ended up with. Ended up drilling through the girt behind the stud pack and, because of the angle, had the go through the horizontal girt to turn the vent vertical again.
If I had started lower on the drain stub up, like Wayne suggested, may have cleared that horizontal girt.

 

[Jeff H Young]

ok looks good no second guessing now its fine no concern on to next obstacle lol

 

[Dmt78]

ok looks good no second gussing now its fine no concern on to next obstacle lol

lol yeah you’re right. Learning as I go thanks to everyone’s help.