Clothes Washer Drain 3"?

[Tuttles Revenge]

So on a job recently a plumbing inspector berated one of our plumbers for not installing 3" drain to the clothes washer. The locality is unicorporated King County and falls under 2018 Washington state amended UPC. None of the amendments specify anything to do with clothes washers.

Its apparently come up a couple other places or my plumber made it sound like it had, but this one just took the cake. She literally was swearing at him about how he should "Effing know this stuff"

He did explain to the inspector that was his interpretation of the code and that we pass inspections all the time with this configuration and that there were structural limitations to even attempting to get 3" into the wall.. She then said to leave it and signed off the rough in inspection.

2" horizontal can handle 8DFU and a Clothes washer is only 3...

Anyone have any insight as to why this would come up?

 

[Terry]

Sounds like an IPC thing on the East coast.
What about expansion tanks for tankless in Kirkland? Asking for a friend.

 

[Sponsor]

 

[John Gayewski]

Sounds like a dummy.

Makes no sense.

I think the IPC is 3" for a clothes washer plus any other thing like a lav or anything. Was there anything else tied into this?

 

[John Gayewski]

Sounds like an IPC thing on the East coast.
What about expansion tanks for tankless in Kirkland? Asking for a friend.

An open system?

 

[Terry]

I had a home in Bellevue where I ran 1.5 for the washer in ABS. Most homes in the 60's had 1.5" run with galvanized.
I later sold that home, and it quickly got torn down. It had been built around 1950 as a temporary home while they had built a bigger one on the front of their acre. I did install a sewer line 220 feet and replaced the 350 foot water service while I lived there.

 

[Terry]

An open system?

There might be a check on the meter.
My tank water heaters always get expansion tanks.

 

[Tuttles Revenge]

Sounds like a dummy.

Makes no sense.

I think the IPC is 3" for a clothes washer plus any other thing like a lav or anything. Was there anything else tied into this?

I dont know if there was, but if so it still wouldnt require 3" up to the trap arm. They had a rim joist on top of a concrete wall that prevented them

 

[Terry]

So Doug, Is this what they're doing here with the expansion tank?

 

[John Gayewski]

So Doug, Is this what they're doing here with the expansion tank?

Wow. I just saw this in a spec book for a job I'm starting next week. That's handy. Tiny tank lol.