Help with Kitchen Sink and Laundry Plumbing (venting)

[Higgs]

Hello and good day to all of you.

First of all thanks for taking the time to read this post!

I am a DYI enthusiast and currently working on a kitchen sink + laundry plumbing and I have the sink drain connected to the laundry drain, is this allowed?

I planned to connect the laundry drain to the upper vent line you see in the picture (using a tee on its back sligtly turned and 22.5 angle fitting) but now, if the drain connections are ok, then should I connect the vent before or after the wye connected to the kitchen sink. Please note the kitchen sink drain has its own vent.

Last question, is there a better way to do this?

Kindly refer to the pictures. Thanks so much for your help and expert advice!

Regards
Plumbing enthusiast!

 

[Sylvan]

Looks great

 

[Sponsor]

 

[Reach4]

I think IPC would like this. I think UPC would not due to santee on its back for ,and the trap being below the prescribed elevation.

New Jersey NSPC? Dunno https://epubs.iapmo.org/NSPC/NJ2021/

I saw nothing specifying a minimum trap height above the floor. As to the santee on its back, I saw somebody say "In NJ it's legal if it is a dry vent ", but that is not authoritative. I am thinking you are OK.

 

[wwhitney]

As you have individually vented both the kitchen sink trap arm and the laundry standpipe trap arm, after venting the drains can connect and be routed anyway you like. You show the laundry standpipe vent takeoff in the correct location, it needs to be before the laundry standpipe trap arm joins another drain.

As for a better way to do it, it looks like it would be possible to avoid having a vent cross over a drain, by raising the standpipe trap above the floor a bit (check the NSPC, which NJ uses, to see if it has a maximum height; the IPC does not, but the UPC limits it to 18" IIRC) and dropping the kitchen sink drain after the vent takeoff (e.g. change the san-tee on its back to a san-tee in the usual orientation with a LT90 on the outlet), and having the kitchen sink drain pass under the laundry standpipe trap. All while keep the wye at its current elevation; the laundry standpipe would be connecting to the branch entry, with the kitchen sink connecting to the horizontal entry.

But with the holes already drilled, and the framing having sufficient depth for the vent/drain crossing, I wouldn't think it's worth redoing. Your vent only has to be 1-1/2".

Cheers, Wayne

 

[wwhitney]

UPC . . . the trap being below the prescribed elevation.

UPC 804.1 says the laundry standpipe trap "shall be roughed in not less than 6 inches (152 mm) and not more than 18 inches (457 mm) above the floor." It's not clear to me that the picture violates the not less than 6" part. The UPC 804.1 rule doesn't actually specify where you measure to on the trap, could be the bottom of the u-bend, the bottom of the outlet, the middle of the outlet, or the top of the outlet.

Just an aside, as NJ doesn't use the UPC, it uses the NSPC.

Cheers, Wayne

 

[Higgs]

As you have individually vented both the kitchen sink trap arm and the laundry standpipe trap arm, after venting the drains can connect and be routed anyway you like. You show the laundry standpipe vent takeoff in the correct location, it needs to be before the laundry standpipe trap arm joins another drain.

As for a better way to do it, it looks like it would be possible to avoid having a vent cross over a drain, by raising the standpipe trap above the floor a bit (check the NSPC, which NJ uses, to see if it has a maximum height; the IPC does not, but the UPC limits it to 18" IIRC) and dropping the kitchen sink drain after the vent takeoff (e.g. change the san-tee on its back to a san-tee in the usual orientation with a LT90 on the outlet), and having the kitchen sink drain pass under the laundry standpipe trap. All while keep the wye at its current elevation; the laundry standpipe would be connecting to the branch entry, with the kitchen sink connecting to the horizontal entry.

But with the holes already drilled, and the framing having sufficient depth for the vent/drain crossing, I wouldn't think it's worth redoing. Your vent only has to be 1-1/2".

Cheers, Wayne

Thanks so much Wayne, highly appreciated.