Home>Discussions>PLUMBING>kitchen sink, no trap no vent, HELP!
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craigmg
kitchen sink, no trap no vent, HELP!

We have an 1892 kind of renovated brick house. Our double kitchen sink stinks because it has no trap, and the waste drain is vertical beneath the sink drains. I don't know how to even put an s-trap (I know not to code) or p trap without the space, or try AAV or cut the wall and vent outside with some weird drain arrangement.

There is a joist which prevents easily getting a pipe at the back where it is supposed to be. I don't want to just hash it again like the previous owners did, but I have no idea how to do it as "proper" as possible with the limitations in place.

after 10 posts I can submit pictures which I am sure would be far more useful than my description

johnjh2o
Re: kitchen sink, no trap no vent, HELP!

The drain line can be at any location under the sink. To use a AAV Just install a sanitary tee on the vertical pipe, connect the trap to the branch of the tee so it ends under the sink drain opening and install the AAV as high as possible on the run of the tee. (top side of the tee)

John

craigmg
Re: kitchen sink, no trap no vent, HELP!

Thanks for the reply John. This is just to make sure I understand, so the end result would look something like my drawing here?

A couple other pics are for seeing what is behind the wood front of the cabinet.

Just another thought. I can get at the pipe really easily in the basement. Could I put the trap here where it elbows to the main drain with an AAV at the top (under the sink)? That way there would be just one trap for both of the fixtures, or would this not work correctly.

craigmg
Re: kitchen sink, no trap no vent, HELP!

Hi John,

Thanks for responding. I tried to add a pic to make sure I understood this, but it went into a moderating black hole and two weeks later still hasn't shown up.

With this being a double sink, can I use the kind of tee with four connections? I have each sink drain running to the vertical drain, so a sanitary tee is being used now except it is in a literal T configuration. I would need an extra opening at the top to install the AAV. At this point I'm thinking I can add the p trap to each sink before it runs to this T, or could I do just one large trap where the drain pipe goes into the basement (meaning I would need only one and there is more space down there, this would be far below the two sinks though.

JLMCDANIEL
Re: kitchen sink, no trap no vent, HELP!

Craigmg, a simpler solution would be to install a trap at the elbow of the black plastic pipe below the floor, you could also install a vent or AAV at that point.

Jack

craigmg
Re: kitchen sink, no trap no vent, HELP!

Hi Jack,

I was hoping someone would say that would work. With a trap fitted there, where would I put the AAV? I was thinking it would have to be above the sink drain.

Could I use a 45 degree wye pipe and then have a vertical with the AAV at the top? This would mean the AAV would be on its own vertical pipe behind the pipe coming down from the sink to the drain. Or do I need it to be further away from the drain pipe.

dj1
Re: kitchen sink, no trap no vent, HELP!

Your top picture with your green markings will work. There is a connector called "double sanitary Tee", it has an outlet on top, where you can attach your AAV. Use it in the intersection of the sink and the GD.

The only possible problem that I can foresee, is whether or not AAV is allowed in your city. Check with your building department before you start.

johnjh2o
Re: kitchen sink, no trap no vent, HELP!

You can not put the trap below the floor. There are limits as to how far the trap can be from it's fixture. With the trap below the floor you far beyond these limits.

John

HoustonRemodeler
Re: kitchen sink, no trap no vent, HELP!

What John said and for a good reason; if the trap is too far down, the force of the falling water will drain the remaining water out of the trap,, allowing sewer gasses to come into the kitchen.

From the looks of that plumbing, I'd be starting over and doing things correctly, this time using a level,tape measure, and some pipe clamps. :eek:

JLMCDANIEL
Re: kitchen sink, no trap no vent, HELP!

I thought the the limit was 5 feet for the trap supply, and i think in this case it would be well within that range. Tub and shower traps are almost always below the floor. The AAV would be installed after the P trap. I do believe however that the green drawings would be the easiest and best solution.

Jack

johnjh2o
Re: kitchen sink, no trap no vent, HELP!
JLMCDANIEL wrote:

I thought the the limit was 5 feet for the trap supply, and i think in this case it would be well within that range. Tub and shower traps are almost always below the floor. The AAV would be installed after the P trap. I do believe however that the green drawings would be the easiest and best solution.

Jack

Jack the limit in most codes is 30". A shower or tub trap is below the floor but it is well within the 30" limit. Also the AAV must be after the trap.

John

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