Extending a Waste-Supply - Lazy Option?

[brianfoley]

Hi there,

I'm kinda new to all this and hoping that someone may be able to prod me in the right direction. I have decided (read: my girlfriend has told me) that our kitchen sink is to be moved to where "we get the sun".

It's a nice idea, but it means that there will be no waste pipe where the sink is to be and we have only just tiled the floor.

Is it possible (I know it wouldn't be ideal) to leave the waste-pipe where it is and trail a pipe extension - through existing kitchen units (would only be through one) to the new location? The plan would be to come up with something like this:



The reality of the situation, however, is a little less straight-forward, as I would like the pipe to take a few bends and was thinking about using flexible PVC pipe to keep it as close to the rear of the units as possible?

Does this strike anyone as impossible, or breaching some particular golden rule that I may be ignorant of? Perhaps I'm missing something obvious about pressure?

Thanks for any help

Brian

[jadnashua]

Probably won't work or meet code. All sorts of crud goes down a kitchen sink. First, you would need to maintain the 1/4" per foot slope - you probably won't have enough height to do that. Second, it doesn't appear that you are going to move the vent...it would be too far away in its present position. You might get away with an aav (air-admittance-valve) instead. If you can overcome those two things, you mightget a reliable connection. A flexible line would not (as far as I understand - I'm not a pro) meet code, and would be rife for trapping crud and clogs. Getting a rigid pipe in now could be a big pain. You might do it with a few couplings - depends somewhat on how large the cabinets are. You doing new countertops? what are you goingto do with the existing hole?

Running water new supply lines to the relocated sink should be doable.

So, maybe...

[Mikey]

Might be easier to move the window.

[hj]

The way you have it drawn and the way your text reads, you may be breaking a lot of the golden rules.

[Verdeboy]

I don't know what the whole hullabaloo is about. We're talking about a sink drain, not an atomic reactor. The worst thing that can happen, is that the sink backs up.

What I'd recommend is to pitch the drain extension at the maximum possible slope, and if you plan on using some couplings, use PVC with nuts that you can easily open in case of a clog. In order to help prevent clogs, I'd stay away from using a garbage disposal.

Enjoy the sunshine!!

[Gary Swart]

With all due respect, you need to tell your GF that moving plumbing around is not like moving the sofa, table, and recliner around. As a novice, you would be well advised to have a plumber evaluate the problem and get the job done properly. The "Golden Rules" are not just lofty ideals that we can just overlook if it's not convienent to follow them. There are sound reasons why things have to be plumbed in a particular way.

[kordts]

If it's less than 4 or 5 foot, I think, you can arm it over, without worrying about the vent. Farther than that, I would revent it back to the original vent riser, 6 inches above the flood rim. You need to use long sweeps when you turn any corners.

[brianfoley]

First, you would need to maintain the 1/4" per foot slope - you probably won't have enough height to do that.

.

Thanks, but as I understand things the slope ratio refers to the minimum necessary slope for proper drainage rather than an absolute requirement. So, if the space actually allowed for a higher gradient (which it does - about a 20 degree slope), then it should be ok?

In respect of code - it's not an issue for me - jurisdiction issues.

Thanks again

[brianfoley]

I don't know what the whole hullabaloo is about. We're talking about a sink drain, not an atomic reactor. The worst thing that can happen, is that the sink backs up.

What I'd recommend is to pitch the drain extension at the maximum possible slope, and if you plan on using some couplings, use PVC with nuts that you can easily open in case of a clog. In order to help prevent clogs, I'd stay away from using a garbage disposal.

Enjoy the sunshine!!

It's weird how I gravitate towards the most favourable response!

Ah seriously though...thanks everyone. The diagram was perhaps misleading and was simply to get the "idea" across rather than offer proportionate dimensions. The actual space between the waste-pipe-fixed-in-floor and the new location is quite small - probably under 5 feet.

Plumber will be in as part of a whole new kitchen fitting exercise I reckon, but I'm just not keen on letting anyone eat into the floor...again.

[brianfoley]

With all due respect, you need to tell your GF that moving plumbing around is not like moving the sofa, table, and recliner around. As a novice, you would be well advised to have a plumber evaluate the problem and get the job done properly. The "Golden Rules" are not just lofty ideals that we can just overlook if it's not convienent to follow them. There are sound reasons why things have to be plumbed in a particular way.

Granted. But I wasn't asking whether I could do it, but whether it could be done.

In this country, one rarely tends to get people out to look at work who then tell you that it doesn't need to be done. So, I simply wouldn't trust someone to come out and say "ahh yeah, you need to open up the floor again...re-line the vent under the ground...I can do it for about one and a half grand". Hence me looking for advice here.

[hj]

You can do it anyway you want to if doing it correctly is not an issue. In fact if it is done according to your drawing, you don't even need a trap, because everytime you drain the sink the trap's seall will be siphoned out anyway, especially if you use the 20 degree slope.

[brianfoley]

You can do it anyway you want to if doing it correctly is not an issue.

Granted. But there is more than one correct way to do many things. The very helpful feedback here has suggested a range of reasonable alteratives, rather than one formally deducible "right answer". So, it's not that "doing it correctly is not an issue", but whether "doing it correctly" really involves some of the more intricate steps outlined above - in particular with regard to the AAV (sp?).

In my profession, for example, I could give someone two sets of "correct" ways to deal with a particular problem, but one may be more detailed and tricky than the other.

Don't get me wrong - all this is VERY helpful.

[Lakee911]

I think it would work, but when you go to sell your house, it's going to look...how do they say it...ghetto-rigged. Throw on some duct tape--even if it serves no purpose--helps for the effect!

You could install false backs in the cabinets if you wanted to hide it though.

Much better might be to pull up those three cabinets and trench the floor under them to move it. Might create an illegal S trap though. You could probably run the supply lines in the space under the toe kicks of the cabinets--maybe drain too.

Jason

[Gary Swart]

You began this thread by asking for help in going the right direction on this project, but you seem to be looking for support in doing it your way even if it's wrong. Have you considered what will happen if/when you decide to sell this house? You will not pass the inspection until this is made right.

[Verdeboy]

This forum is like going to the Doctor. I don't always do what my Doctor tells me. I hire him or her for advice. I'm ultimately in charge of my body. In fact, I usually end up throwing out the majority of the prescriptions I get. I'd probably be dead by now if I listened to them and not my own gut feelings.