AAV for a island sink

[Lou94stang]

I am in NY so we follow IPC. There is no
Backsplash to get the vent high enough. So Is it possible to vent the island sink that also has a dishwasher and disposal by using a AAV mounted as high up as possible. Or I’m a stuck with using a loop vent. Thanks

 

[BJN]

I am in NY so we follow IPC. There is no
Backsplash to get the vent high enough. So Is it possible to vent the island sink that also has a dishwasher and disposal by using a AAV mounted as high up as possible. Or I’m a stuck with using a loop vent. Thanks

The AAV only has to be 4” above where the trap arm of the sink hits the vertical drain in the IPC code. Please see the link below. You may have to copy and paste it into your browser, I don’t know if it will hyperlink or not.

CodeNotes: Installation of air admittance valves - ICC

The CodeNotes, Installation of Air Admittance Valves, provides an understanding of the IPC and IRC requirements on the installation of these valves.

www.iccsafe.org

 

[bill1952]

I believe in NYS you can use an AAV by specific permission of the building official. If not, a loop with high point basically to touching underside of counter is your option.

 

[fatboy]

That's how we handle it by ordinance, if conventional vent to atmosphere is possible, then do it. If not feasible, then we will approve the use of an AAV.

 

[steveray]

The AAV's don't really like the "pumping" discharge so read the install instructions....

 

[Glenn]

You can do a single fixture combination waste and vent. Here is an article I wrote on the subject.

A New Old Way to Vent a Kitchen Island - Fine Homebuilding

Code expert Glenn Mathewson describes three ways to vent a kitchen island and explains what the IRC requires. Learn more, here.

www.finehomebuilding.com

 

[Beniah Naylor]

You can do a single fixture combination waste and vent. Here is an article I wrote on the subject.

A New Old Way to Vent a Kitchen Island - Fine Homebuilding

Code expert Glenn Mathewson describes three ways to vent a kitchen island and explains what the IRC requires. Learn more, here.

www.finehomebuilding.com

I did not know that. Is this legal under the UPC as well?

Main reason it matters is that many jurisdictions around here use the UPC, and many of the plumbers around here got their license under the UPC, work in jurisdictions that use the UPC, and so when I discuss plumbing code I like to be able to tell them if something we allow because of the IPC would fail in a UPC jurisdiction.

 

[Joe.B]

I believe what he's describing would not be expressly accepted by UPC (at least by CPC which is based off UPC) for two reasons:

1. What's described and shown in the picture looks like an S-trap

1004.1 Prohibited

No form of trap that depends for its seal upon the action of movable parts shall be used. No trap that has concealed interior partitions, except those of plastic, glass, or similar corrosion-resisting material, shall be used. "S" traps, bell traps, and crown-vented traps shall be prohibited. No fixture shall be double trapped. Drum and bottle traps shall be installed for special conditions. No trap shall be installed without a vent, except as otherwise provided in this code.

2. No prescriptive section for other than bathroom.

908.2 Horizontal Wet Venting for a Bathroom Group

A bathroom group located on the same floor level shall be permitted to be vented by a horizontal wet vent where all of the conditions of Section 908.2.1 through Section 908.2.5 are met.


BUT, it seems there might be some leeway by:

910.0 Combination Waste and Vent Systems

910.1 Where Permitted

Combination waste and vent systems shall be permitted where structural conditions preclude the installation of conventional systems as otherwise prescribed by this code.

910.2 Approval

Construction documents for each combination waste and vent system shall first be approved by the Authority Having Jurisdiction before a portion of such system is installed.

So.... maybe?

 

[ICE]

This is the configuration that Glenn is talking about:




There is a violation with the dishwasher.

 

[Beniah Naylor]

There is a violation with the dishwasher.

Looks like a san-tee on it's back that everything ties into. Don't see the violation with the dishwasher - although where does it plug in?

Back to being serious. I found this on UpCodes. It is from the Oregon Plumbing Specialty Code, which is based on the UPC. Not sure if they amended this section or not.

910.1 Where Permitted
Combination waste and vent systems shall be permitted where structural conditions preclude the installation of conventional systems as otherwise prescribed by this code.

But right before that, you have this section:

909.0 Special Venting for Island Fixtures

909.1 General

Traps for island sinks and similar equipment shall be roughed in above the floor and shall be permitted to be vented by extending the vent as high as possible, but not less than the drainboard height and then returning it downward and connecting it to the horizontal sink drain immediately downstream from the vertical fixture drain. The return vent shall be connected to the horizontal drain through a wye-branch fitting and shall, in addition, be provided with a foot vent taken off the vertical fixture vent by means of a wye branch immediately below the floor and extending to the nearest partition and then through the roof to the open air, or shall be permitted to be connected to other vents at a point not less than 6 inches (152 mm) above the flood-level rim of the fixtures served. Drainage fittings shall be used on the vent below the floor level, and a slope of not less than 1/4 inch per foot (20.8 mm/m) back to the drain shall be maintained. The return bend used under the drainboard shall be a one-piece fitting or an assembly of a 45 degree (0.79 rad), a 90 degree (1.57 rad), and a 45 degree (0.79 rad) elbow in the order named. Pipe sizing shall be as elsewhere required in this code. The island sink drain, upstream of the returned vent, shall serve no other fixtures. An accessible cleanout shall be installed in the vertical portion of the foot vent.

My guess is that a combination vent for an island will not be permitted in a UPC jurisdiction unless you ask first. Which I would, since it seems like a better option than the loop vent as far as cost, installation, and usability of the space is concerned.

 

[ICE]

Don't see the violation with the dishwasher

414.3 Drainage Connection. Domestic dishwashing machines shall discharge indirectly through an air gap fitting in accordance with Section 807.4 into a waste receptor, a wye branch fitting on the tailpiece of a kitchen sink, or dishwasher connection of a food waste grinder. Commercial dishwashing machines shall discharge indirectly through an air gap or direct connection in accordance with Section 704.3 with floor drain protection.

This is California Plumbing Code based on the UPC and yours may be different.

 

[steveray]

And IRC just for clarity on the dishwasher piece.. Indirect not required....

P2717.2 Sink and dishwasher. The combined discharge
from a dishwasher and a one- or two-compartment sink, with
or without a food-waste disposer, shall be served by a trap of
not less than 11/2 inches (38 mm) in outside diameter. The
dishwasher discharge pipe or tubing shall rise to the underside
of the counter and be fastened or otherwise held in that
position before connecting to the head of the food-waste disposer
or to a wye fitting in the sink tailpiece.

 

[ICE]

And IRC just for clarity on the dishwasher piece.. Indirect not required..

And just for the rest of the country, California did not adopt the plumbing, electrical or mechanical sections of the IRC.