Thread: What do you think

Haven't seen this before. Does the diameter of this pipe make it acceptable to vent properly.

Not likely to cause a problem, but should have (required to have) an AAV.

See it often at island sinks. No known problems but I still explane the loop system for island drains.

James

That looks like remodeling work.
Did you look at the other vents? Bath, toilet

Scratch my last post, looks like it is a Bar sink.

I think original equipment but who knows. thanks for the quick replies

They allow it here as long as the pipe is at least 1.5 x larger.

Originally Posted by wayne soper

Haven't seen this before. Does the diameter of this pipe make it acceptable to vent properly.

Not following what you are asking, but, yes, it is acceptable to vent it properly ... (which it is not)

Originally Posted by wayne soper

Haven't seen this before. Does the diameter of this pipe make it acceptable to vent properly.

They still make TANG?

Maybe it was an astronauts house.

Doesn't look like an AAV on the top of the pipe??? If not, needs an AAV I believe.

James: What loop?

Frank: 1.5x larger? So, in your area a 2" shower drain needs to be vented by a 3" pipe?

Robert: It's not a vent, it's a rubber cap. So...

That's an elaborate S-trap. Plumber probably didn't have one on the truck at the time, forgot to go back and put one on. Or was lazy.

That's not an S-Trap and if that's a rubber cap the plumber forgot the AAV.

Originally Posted by Robert Dalga

That's not an S-Trap and if that's a rubber cap the plumber forgot the AAV.

Because they did not vent it, it is effectively an S-trap ... it will suffer from the same problems for the same reasons.

Originally Posted by Jerry Peck

Because they did not vent it, it is effectively an S-trap ... it will suffer from the same problems for the same reasons.

An S-trap could siphon itself dry, and that is a bad thing. Are you saying this unvented P-trap will siphon itself dry? I think not.

No offence intended, I know it is not correctly plumbed. But I suspect it works just fine. There is no way there will be enough suction on that trap to draw water out of it. I would point it out as incorrect and move on.

They do them that way under peninsula and island kitchen cabinets here all the time and they work fine. The AHJs here do allow it and it is commonplace on new construction.

I know, only in OK and we're a bunch of morons, blah blah blah.

Originally Posted by John Kogel

An S-trap could siphon itself dry, and that is a bad thing. Are you saying this unvented P-trap will siphon itself dry? I think not.

You can bet it will, in fact ... that is why it is required to be vented.

Originally Posted by Frank Bombardiere

They do them that way under peninsula and island kitchen cabinets here all the time and they work fine. The AHJs here do allow it and it is commonplace on new construction.

That is not how island and peninsula sinks are done ... at least that is not how they are SUPPOSED to be done ...

If they are being done that way then they are wrong.

I suspect, however, that you are only thinking they are "done that way" when in reality they are done properly and you are just not noticing the difference.

A AAV will not work unless its installed above the flood rim.

Attachment of an island sink venting set up.

Originally Posted by Raymond Wand

A AAV will not work unless its installed above the flood rim.

Attachment of an island sink venting set up.

I like what Raymond has posted. this is what I put on my reports.

Best

Ron Bibler
EXCELLENCE HOME/BUILDING INSPECTION SERVICE
Petaluma California Home Inspection - Exterminating & Thermal Imaging
www.sonomahomeinspection.com
Vacaville California Home Inspection - Exterminating & Thermal Imaging

Originally Posted by wayne soper

Haven't seen this before. Does the diameter of this pipe make it acceptable to vent properly.

It looks ok as long as the 3" trap arm is not over 12 feet.

Originally Posted by Raymond Wand

A AAV will not work unless its installed above the flood rim.

Attachment of an island sink venting set up.

Here is what the NC code says about the location of AAV's. Your state's code may be different when it comes to the required height.

917.4 Location. The air admittance valve shall be located a
minimum of 4 inches (102 mm) above the horizontal branch
drain or fixture drain being vented The air admittance valve
shall be located within the maximum developed length permitted
for the vent. The air admittance valve shall be installed a

minimum of 6 inches (152 mm) above insulation materials.

Originally Posted by Jerry Peck

You can bet it will, in fact ... that is why it is required to be vented.

Jerry, I believe the rule says it will but I say it won"t.
I challenge you to make a 3" plumbing stack draw hard enough on a 1" P-trap to suck a teaspoon of water.

It is 9 times larger in volume.

If it's less than 12' to a vent, wouldn't it be considered a wet vent which would be acceptable?

Originally Posted by Raymond Wand

A AAV will not work unless its installed above the flood rim.

An AAV *does not* need to be above the flood level rim of the fixture.

Not sure where you got that information from?

Originally Posted by Jerry Peck

An AAV *does not* need to be above the flood level rim of the fixture.

Not sure where you got that information from?

Jerry

I am glad you asked the question.

the Ontario Building Code, Section 7.5.9.2 ("Air Admittance Valves") states that "The air admittance valves shall be located, (a) above the flood level rim of the fixture it serves, ..."

This definition is provided:

Flood level rim means the top edge at which water can overflow from a fixture or device.

7.5.9.2. Air Admittance Valves
(1) Air admittance valves shall only be used to vent,
(a) fixtures in buildings undergoing renovation, and
(b) installations where connection to a vent may not be practical.
(2) The air admittance valves shall be located,
(a) above the flood level rim of the fixture it serves,
(b) within the maximum developed length permitted for the vent,
(c) not less than 150 mm above insulation materials, and
(d) installed in a location not subject to back pressure.
(3) Air admittance valves shall,
(a) only vent fixtures located on the same storey, and
(b) be connected to the horizontal fixture drain.

7.5.9.3. Installation Conditions
(1) Air admittance valves shall not be installed in supply or return air plenums, or in locations where they may be exposed to freezing temperatures.
(2) Air admittance valves shall be installed in accordance with the manufacturer’s installation instructions.
(3) Air admittance valves shall be rated for the size of vent pipe to which they are connected.
(4) Installed air admittance valves shall be,
(a) accessible, and
(b) located in a space that allows air to enter the valve.
(5) Every drainage system shall have one vent that terminates to open air in conformance with Sentence 7.5.6.2.(1).

Originally Posted by Raymond Wand

the Ontario Building Code, Section 7.5.9.2 ("Air Admittance Valves") states that "The air admittance valves shall be located, (a) above the flood level rim of the fixture it serves, ..."

Not required by any AAV manufacturer, but ... if Ontario decides it knows better than everyone else, so be it.

Good morning Jerry,

I did note the caveat in the code reference about manufactures instructions.

Thanks for the feedback.

Cheers,