Question about relief vent for laundry

[Peter R]

As part of a renovation, we're reconfiguring our laundry room. The new location of the washing machine places it more than 5 ft. from the existing stack into which it will drain and would otherwise vent. But, code requires a vent within 5 ft.

I can't run a vent straight up, because it is against an exterior brick wall and, well, I don't much feel like channeling out that much brick. So, while not ideal, the vent can't be placed in the wall. I'd like to run a relief vent through a chase in the corner of the room (other end of the wall from the stack). I'll tie back into the stack in the attic.

So, my questions is: Is it okay to place the trap on a horizontal run (with the appropriate 1/4" pitch, of course) between drain and the relief vent? It seems that diagrams of relief vents usually depict the vent taking off between the trap and drain.

Thanks in advance for helping a novice out.

 

[Tom Sawyer]

Short answer is no.

 

[Sponsor]

 

[Reach4]

Look up about AAV (air admittance valve) units for venting.

I think some have a problem with letting you put the bottom of the laundry trap below the floor.

https://terrylove.com/forums/index.php?threads/washing-machine-drain.20625/
https://terrylove.com/forums/index.php?threads/new-washing-machine-vent-question.49793/
https://terrylove.com/forums/index.php?threads/washer-drainage-in-basement.45285/

 

[Peter R]

Thanks for the prompt responses.

The horizontal run will actually be above the floor, running through cabinets and behind the washer/dryer. I should have noted the floor level on th diagram.

AAVs are out of the questions, as they aren't allowed in my area, and this is a permitted job—to be inspected. My local code is UPC.

Tom Sawyer, can I assume the issue is with the flat vent before it takes off vertically (905.2)? I suppose if I go up with the vent from the trap above the flood level of the highest fixture (washing machine) and over to the corner of the room, that would comply with code?

Thanks again.

 

[Terry]

Can I assume the issue is with the flat vent before it takes off vertically (905.2)? I suppose if I go up with the vent from the trap above the flood level of the highest fixture (washing machine) and over to the corner of the room, that would comply with code?

Thanks again.

Yes, the vent needs to be above the flood level before it goes horizontal.
The washer can go into a wet stack, but not a vent stack. Is the the stack to the left waste or vent?

 

[Peter R]

Thanks, Terry. Yes, the stack to the left is the main waste stack in the house, going to the basement floor and venting through the roof.

Basically, my problem is I can't get the washer close enough to the stack (within 5') to properly vent.

I can build out a shallow box behind the washer/dryer to house the plumbing that will allow me to go straight up with the vent and then over (horizontal, above flood level) to the corner of the room before it goes up into the attic. Once in the attic, I can tie it into the stack.

Will that comply with code?

 

[Reach4]

How about this:

 

[Peter R]

Well, that makes perfect sense! If others agree that works, I'll likely do that.

Otherwise, I can build a shallow box behind the washer/dryer to house the plumbing and bring the vent up and over (above flood level) within the box.

 

[Reach4]

Probably should have a cleanout... I am thinking somewhere in the new vent.