Correct way to connect washing machine drain to horizontal waste pipe?

[ajs317]

I'm looking to install the drain pipe and associated vent for a washing machine as detailed in the attached picture, connecting to an existing horizontal drain pipe. I've attached a marked version of how I think it should look, but I'd appreciate it if anyone could tell me if this looks right or if there are any code issues.

The new piping will be in line with the framed wall, which actually sits a few inches out from the existing horizontal pipe that is secured to the concrete foundation through the foam board. I think that will mean that I need to use a slightly angled fitting around where the blue circle is to move the trap arm in line with the horizontal pipe. Does this sound right?

Please ignore the scale of the piping that I drew in. Everything would be 2" PVC.

Any feedback or suggestions on improving this would be much appreciated.

 

[Toolaholic]

I'm looking to install the drain pipe and associated vent for a washing machine as detailed in the attached picture, connecting to an existing horizontal drain pipe. I've attached a marked version of how I think it should look, but I'd appreciate it if anyone could tell me if this looks right or if there are any code issues.

The new piping will be in line with the framed wall, which actually sits a few inches out from the existing horizontal pipe that is secured to the concrete foundation through the foam board. I think that will mean that I need to use a slightly angled fitting around where the blue circle is to move the trap arm in line with the horizontal pipe. Does this sound right?

Please ignore the scale of the piping that I drew in. Everything would be 2" PVC.

Any feedback or suggestions on improving this would be much appreciated.

Where is the hot and cold water valves ??

 

[Sponsor]

 

[wwhitney]

Is the existing PVC drain lower on the right than on the left?

If so, it would probably be easier to connect the horizontal fixture drain to the existing drain via a 45 and a wye. So like a combo wye, but the 45 is turned 90 degrees to be horizontal, rather than vertical. That wye/45 assembly can be rolled forward to account for the perpendicular-to-the-wall difference between the two horizontal lines.

Cheers, Wayne

 

[ajs317]

Where is the hot and cold water valves ??

In that box where the hoses are connected right now. The washer drain is connected to a standpipe on a wall that's catty corner to this one. I'm moving the washer to a wall that's perpendicular to where it used to be.

 

[ajs317]

Is the existing PVC drain lower on the right than on the left?

If so, it would probably be easier to connect the horizontal fixture drain to the existing drain via a 45 and a wye. So like a combo wye, but the 45 is turned 90 degrees to be horizontal, rather than vertical. That wye/45 assembly can be rolled forward to account for the perpendicular-to-the-wall difference between the two horizontal lines.

Cheers, Wayne

Yes, it slopes toward the right side of the picture. I think I see what you're saying with the 45 and wye, and that makes sense. I'll try that.

Any thoughts on the rest of the setup?

 

[ajs317]

One other question: do I need the trap arm to extend beyond (to the right in my picture) of the vent? Or can I run the trap arm into a san tee and then have a single vertical pipe running up to the AAV and down to a wye and 1/8 bend to connect to the existing horizontal pipe?

 

[Terry]

Something like this would drop into your horizontal with a combo fitting at the bottom. I don't know why you would add and extra 90 to it.

 

[ajs317]

Thanks, Terry. Agree, I don’t think I need that extra 90. The picture makes sense. Appreciate it.

 

[wwhitney]

One other question: do I need the trap arm to extend beyond (to the right in my picture) of the vent? Or can I run the trap arm into a san tee and then have a single vertical pipe running up to the AAV and down to a wye and 1/8 bend to connect to the existing horizontal pipe?

Your original idea would use a combo to connect the vent to the horizontal trap arm, then a 45 and a wye as I suggested to connect up to the existing horizontal line.

If you use a san-tee for your vent takeoff (with a straight riser on the vent to the AAV box), the drain outlet of the san-tee is vertical, and that outlet is not over the existing horizontal drain line. So to connect up you'll need something like a 22.5, a 45, and a wye.

The second drain path has more bends in it, but either way will work.

Cheers, Wayne

 

[wwhitney]

P.S. One more option:

The above options all have the trap arm in the stud wall. You could instead swivel the trap around so that the outlet is directly above the existing drain and parallel to it. Then you don't need to do the out-of-plane jog when connecting to the drain. You would need to jog the vent back to hit the AAV box in the stud wall.

Cheers, Wayne

 

[ajs317]

Thanks, Wayne, very clear and helpful. I'll play with these options and see what's easiest to execute.