Studor Mini-vent

[Cleadus Robinson]

I am planning to relocate my utility room (hot water heater, washer/dryer and sink) to the gargage. I plan to install two sinks on opposite walls (one for laundry and one for other) and instead of running a new vent through the roof I was thinking of using the mini-vent instead. Can I tie both sinks into a single mini-vent?

[Dom D'Agostino]

Assuming you meet the typical requirements, here are Studor's specs and design info for their product.

http://www.ipscorp.com/pdf/studor/Studor_MiniVent_Spec_Sep08.pdf

Being that the sinks are on opposite walls, it's much easier to add another $15.00 AAV under the sink.

[Jerry Peck]

The sinks would be too far apart for one vent (of any type, even one open to atmosphere above the roof) to serve.

Here are a couple of maximum allowable distances from the trap to the vent for a common pipe sizes:
1-1/4" pipe - 5 feet maximum from trap weir to vent
1-1/2" pipe - 6 feet maximum from trap weir to vent
2" pipe - 8 feet maximum from trap weir to vent

Each of the above is based on the minimum 1/4" per foot slope, if you increase the slope, you reduce the allowable distance between the trap and the vent.

[Joshua Hardesty]

The sinks would be too far apart for one vent (of any type, even one open to atmosphere above the roof) to serve.

Here are a couple of maximum allowable distances from the trap to the vent for a common pipe sizes:
1-1/4" pipe - 5 feet maximum from trap weir to vent
1-1/2" pipe - 6 feet maximum from trap weir to vent
2" pipe - 8 feet maximum from trap weir to vent

Each of the above is based on the minimum 1/4" per foot slope, if you increase the slope, you reduce the allowable distance between the trap and the vent.

Not to mention, for that to work at all, the trap would have to be below the floor.

[Ken Rowe]

You'll need to check your local codes. Studor vents are not allowed everywhere.

[H.G. Watson, Sr.]

Developed lengths, etc. and design requirements for plumbing are significantly different in the UPC than in the IPC. IIRC Washington State uses the UPC (Uniform Plumbing Code), not the IRC or IPC ("International Codes, or I-Codes) for residential plumbing.

As mentioned you'd need the approval from your local authority. UPC requires all developed venting through the roof, but an exception with expressed local authority approval might be possible, however the limit is ONE per structure. I am doubtful you could gain such an approval for your garage plumbing project. Since the garage would likely not be conditioned, an AAV wouldn't be protected from freezing, so it would most likely not be approved.

You would require a permit regardless to do any of what you propose.

STUDOR (R) inVENTive Technology (TM) - Air Admittance Valves (http://www.studor.com/approvals.htm)