Plumbing vent

[Phisherman]

I've been reading about the proper way to vent a utility sink in the basement. After looking at the existing plumbing I discovered that a first floor bath and kitchen sink share a single (wet) vent. Only the bath sink has a dry vent. I bought this house (new construction) in

1992. All the plumbing books say that every fixture must have its own vent, yet clearly this is not the case and it passed city inspection. Since this configuration has not had any problems since 1992, I'd say it works just fine but not to code. Is this a common occurrence? Are there any perfect plumbing systems?

[Speedy Jim]

The answer may lie in the fact that the US does not have one single recognized plumbing code; accepted practice varies across the country. And even locally, there may be exceptions to the published code(s).

So it's hard to say. But as you noted, wet vents have pretty much gone the way of the horse and buggy.

Jim

[Big_Jake]

I am doing a major addition on my house right now, and the plumber has wet vented at least one fixture, possibly two.

How many plumbing books do you own, since you make the statement "all the plumbing books say..."?

Here's a discussion and some of the rules for wet venting from Terry Love's site:

JK

[Phisherman]

I don't own any plumbing books. I read parts of a plumbing code reference book in the local library and checked out 4 how-to books that are 2003 or later. I also found (like Speedy Jim pointed out) that plumbing is not nearly as standardized as electrical code. Thanks for the link!

[RicodJour]

An air admittance valve is a simple way to do it. Check out Oatey's site for info.

R

[Mark]

A Wet Vent is one where waste from another fixture drains thru the vent from another fixture. Are you sure this what is happening with your first floor bath and sink? They could share a common vent?