Another laundry sink question

[Benbo]

Hi All,

I'm trying to hook up a laundry sing in my garage next to the existing washer drain. I was hoping to use the configuration called out in 802.4.3.1, but in my application the P-trap is on the wrong side of the vent. Any ideas how I might solve this?

Thanks much!

 

[Bannerman]

If the vent pipe above the existing 'Tee' connection for the standpipe P-trap connection is cut to install an additional Tee and P-trap for the new sink, will that be too high to connect the new sink?

 

[Sponsor]

 

[Benbo]

Yep - the bottom of the new sink is 21" high. With a 1/4" fall, a straight pipe like shown in the 802.4.3.1 drawing hits right at the cleanout. My latest idea is to bring the vent pipe over to the other side of the stud bay above the washer box and mirror the existing p-trap. If it all lines up, that would let me attach the sink drain above the p-trap.

 

[Bannerman]

Your drawing shows one P-trap serving both the sink and laundry machine stand-pipe.

My initial suggestion was to cut the vertical vent/drain line above the existing Tee and clean out area to install a 2nd Tee above facing the garage. The new sink would require its own P-trap but as I anticipate that horizontal trap arm distance will be less than 30" before connecting to the vertical drain line, it may not need an additional vent, as shown in the code diagram.

Because the sink will typically require a tailpiece between the drain assembly and P-trap fitting, that will likely further lower the connection height. Perhaps the clean out could be located above both Tees if the new drain location will need to be lower than the existing Tee.

A possible alternative Tee location could be in the short vertical section between the existing stand pipe elbow and the P-trap. As it appears that vertical section may be too short to fit a Tee, you may need to raise the height of the laundry machine connection box maybe an inch or two. This will then allow the existing P-trap to also serve the new sink as shown in the code diagram.

 

[Benbo]

Yes - the tricky part is the sink tailpiece is only 14" above the bottom plate. What do you think of this setup - I moved the vent pipe over and reversed the p-trap from the washer box.