Thread: Kitchen sink peninsula.

This is a kitchen sink on a peninsula. Does there need to be an air inlet? Is this plumbed correctly?

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Originally Posted by David D. Whitt

This is a kitchen sink on a peninsula. Does there need to be an air inlet? Is this plumbed correctly?

Should be a studer vent. Also the washer drain line coming up at an angle probably means there is no high loop and or air gap. Disposal looks like the housing is cracked and has been leaking and the rest is on you

An island loop vent could work, as could a traditional vent.

If permitted perhaps an Air Admittance Vent.

As to the drains/traps, no not correct.

Thanks guys

I'm still wondering why there is a 3" or 4" riser( it's hard to tell from the pics) to a double bowl sink? What other little issues might be found? Was a vent stack cut to accomplish this install?

I found a picture of the underside and it looks like there is a 3" t-wye with a 2" vent going up. What I do not understand is that where that 2" pipe goes up, there is no wall that goes to the ceiling, only the cabinet wall. I am wondering now if that 2" pipe is the vent

In some areas there is some obscure part of the code where if you over size the vertical drain the code will allow no vent. I seen some plumbers post about that style of drain. I would show the pictures to the local plumbing inspector and see if that is something allowed by your local code.

Personally I do not agree with it, and here in Illinois it would not be allowed. Also Illinois does not allow mechanical vents. And yes an AAV even by Studor is a mechanical vent.

Hi David, don't know about your Code but ours doesn't allow dishwasher to be drained to the disposal. Also take a look at the attached pdf for a typical island loop vent.

Originally Posted by Markus Keller

Hi David, don't know about your Code but ours doesn't allow dishwasher to be drained to the disposal. Also take a look at the attached pdf for a typical island loop vent.

Yep you are correct. Also note our code requires the disposal to be on its own trap it cannot share a trap with the other bowl. One more note about traps the code requires each bowl to have its own trap if there is more than 6" difference in the depth of each bowl. But if the bowls are all the same depth we are allowed to run up to three compartments through one trap.

Just figured I add a little bit more knowlage of the Illinois Plumbing code.

That crawl space leaves a little to be desired. Is that wiring going through the block wall?

D.D.W.,
No regarding your post #6 and photo ID on the fitting. That is a san-tee not a tee-wye. There is quite a bit wrong in that photo, appears to be a DIY or unqualified mess. There are appropriate fittings which have not been used. Installation issues abound. It goes without saying ventillation ducts hanging from plumbing via tape is also wrong.

Regards to the under-the-sink photos in Post 1, the horizontal fixture arm wye is not correct. Horizontal drains require more of a sweep to prevent clogs. The additional sweep of a true combo tee-wye or a wye with a sweeping 1/4 bend or perhaps an 1/8 bend in combination with a wye might do to enough sweep. San-tees may NEVER be on their side.

Back to photo from post 6, without a deterination of the path of the vertical above the san-tee photo from post 6 it is unknown if same is a vent, a wet-vent, etc. the install is wrong regardless.

Some review of fittings might be helpful to you.

I believe R.H. might be referring to "philadelphia system" plumbing or an ex. for horizontal branch to toilet.

One of the problems with the under-sink arrangement is that there is no trap protection. A forceful slug, i.e. from having both sinks pluged, one filled and suddenly emptied, or d/w drainage could cause the traps to completely empty. No syphon protection either for the d/w drain. 1-1/4" trap for disposal sink bowl also n/g requires min 1-1/2". Thin-walled pvc also n/g for this application (either sink bowl trap). Much more wrong with this overall installation.

A duly licensed plumber is required, probably since such extensive issues exist, a master plumber, to design a compliant system configuration, as photographed the configuration is a health hazard and to properly remediate, calculations for the system, not just the branches, are required.