How do I loop a drain with out access to a vent line?

Loop vent is vented. If you don't have existing vent inside nearest wall, you will have to run new one.

What are you exactly doing? Post lay-out of your sink showing nearest walls. Is it inside an island in the middle of your kitchen ? Are you on slab? What city are you in ? You may get away with AAV. Is the project inspected ?

Please, post these details so we can help...

You are describibg a Chicago loop vent often used where we install sinks in kitchen islands. Chicago Loop (plumbing - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Chicago_Loop_(plumbing)) sometimes you can also install a AAV (air admittance vent) but many codes do not allow them.

Ballengerb: yep, it would be lot easier if posters included simple sketch of their project and their geo-location. Let's hope he/she will come back...

How do I loop a drain with out access to a vent line?


Wikipedia does not have an article with this exact title. Please search for Chicago Loop (plumbing in Wikipedia to check for alternative titles or spellings.
And no wonder. Chicago loop Vent is a local name. What we have here is a Island Sink Vent,(see images) I have put up two versions. One is a regular Island loop vent and the other is a loop vent using a AAV. Good luck tom

I sure though I had posted the pic but apparently not. http://www.powerset.com/explore/go/Chicago-Loop-(plumbing)

I sure though I had posted the pic but apparently not. Chicago Loop (plumbing - Powerset (http://www.powerset.com/explore/go/Chicago-Loop-(plumbing))

That drawing in the link is wrong by our Code. It doesn't have 3 required clean outs: 2 on the loop vent, one on the drain...

Just thought I should share this detail with you...

Thanks Milo, But the other 90% of the country doesn't live in California. Why are two cleanouts required on one vent line? You have two lines inder the counter, one drain and one vent. Where does the extra cleanout install? Regards, Tom

Guess this is why is not called an LA Loop .

Guess this is why is not called an LA Loop .

With three cleanouts it's a "California Loopy Vent" in my book. LOL, Tom