P-trap location

[skatona]

I need to run a kitchen sink drain line roughly 3 feet through a few cabinets to get to the through-wall connection (due to layout of framing). Are there any "rules" regarding where the p-trap needs to be? Can I put it all the way over near the wall connection, or does it need to be under the sink?

 

[Dlarrivee]

Under the sink.

Running traps aren't allowed.

 

[Sponsor]

 

[Jimbo]

Please be careful to have slope ( 1/4" per foot) on that arm over from the trap through the cabinets to the wall. Yours is not an uncommon situation, due to things like kitchen windows. If that arm is allowed to be flat, so close to the sink, it will quickly be a gunk-catcher. Get in the habit of running the water at lease a minute or two AFTER the disposal runs, if you use one of those.

 

[hj]

Your life will be a lot easier if you put the trap under the sink. And that would be for several reasons.

 

[NHmaster3015]

Are running traps illegal?

 

[Jerome2877]

Running traps are not to code, however what was decribed wouldn't be a running trap. It wouldn't be much different from an ada sink. That being said I agree with putting the trap under the sink if possible.

 

[NHmaster3015]

Who say's they are not to code?

1002.3 Prohibited traps. The following types of traps are prohibited:
1. Traps that depend on moving parts to maintain the seal.
2. Bell traps.
3. Crown-vented traps.
4. Traps not integral with a fixture and that depend on interior
partitions for the seal, except those traps constructed
of an approved material that is resistant to corrosion
anddegradation.
5. "S" traps.
6. Drum traps.
Exception: Drum traps used as solids interceptors and drum
traps serving chemical waste systems shall not be prohibited.

I don't see anything there do you?

 

[Gsalet]

I believe the answer is in the tailpiece definition. a tailpiece connecting to a sink or similar fixture will be as short as possible but not longer than 2 feet (upc 910.5)
personally I like the P-Trap directly under the garbage disposal outlet

 

[NHmaster3015]

Nope tailpiece length has nothing to do with trap location. IE handicap lavs with offset drains. Truthfully, IPC and UPC say nothing about running traps and in fact sometimes trapping a floor drain can require a running trap. Not used commonly and will probably raise eyebrows from uninformed inspectors but unless your code says no......you can

 

[Dlarrivee]

And so because you can, that means you should?

I don't agree.

 

[NHmaster3015]

Well now you are on to a whole different subject. To running trap or not to running trap...that is the question

 

[Shacko]

Running Trap

Wally Hays: I also looked it up, it looks like its not in there anymore but i agree that the inspector is going to have problems passing it

 

[NHmaster3015]

so the question is, Is a running trap a problem or not and why?

 

[Jadnashua]

The longer the drain line before the trap, the more possibility of the potentially nasty bio buildup on the pipe will create nasty smells, especially on a kitchen sink where there will likely be grease and food particles that get washed down it. A disposer would add to that bio buildup, especially if the water is not run long enough after use.

 

[NHmaster3015]

The distance from the trap to the drain is still in force.

 

[Geniescience]

without seeing your situation, I won't put myself in the yea or nay camp.

skatona if you buy the remote pop up for kitchen sink drains, it comes with a tight elbow under the sink strainer so it sends your sink drain tailpiece horizontally instead of going down like we usually see it. This is a commercially sold and available product. Yes it is true that this horizontal pipe might get gunk in it, or that it will, and secondly that since it's prior to the P trap any smell the gunk would generate will come into your kitchen. BUT this is not the deal breaker kind of information that you were asking for. From that tight elbow, there is a slip joint to the tubular which goes over to your drain pipe (copper or PVC or whatever), and you have another slip joint at that connection. (((Anyway, that is what I have))). Any time I want to unscrew these slip joints I can do so, easily. I can look inside the tubular, and clean it out. I can look into the copper and clean it too. Easily for a few inches, not for three feet.

So, yes skatona you CAN "run your kitchen sink drain line through a few cabinets to get to the through-wall connection (due to layout of framing)." And the "rules" regarding where the p-trap needs to be will allow it, so that is a yes again. HOWEVER there are good reasons to encourage you to put the P trap closer to the sink drain than roughly 3 feet away. One is the reason described in this post already. Another one is that a P trap closer to the drain makes it easier to snake.

Where is your dishwasher connection? If it can be put close to the sink drain, then this will wash out the horizontal drain prior to the P trap, a lot.

The height from the floor is almost the same, of the pipe prior to the P trap and downstream of the P trap. So, there may be no NEED to put the P trap that far away. As a compromise, I'll suggest you put the P trap closer than 18" from the sink. The portion of pipe that follows the P trap is "Trap Arm" in the DWV code. It can be 2" diameter.

 

[hj]

EVERY grease interceptor is a "running trap", and they ARE permitted. As far as a sink using a running trap, even if it is "permitted" there is no reason to DO it unless there are overwhelming reasons for it, which is seldom the case. The ""remote pop-ups" I have used and seen, all have the mechanism in the vertical drop under the sink, NOT in any offset.