[oodssoo]

Hi,



I am about to get started on my plumbing for the basement project. This will begin with plumbing the drains for the dishwasher/sink with disposal, washer, and vanity/lav drain.



Please reference my novice sketch and let me know your opinions.

(What I am looking for is wether the "stack" order I have drawn is adequate)




Thank you in advance.

 

[AndyGump]

Well...1/4" per foot is what is generally code. Not 1/16" per foot drop.

Andy.

 

[jklingel]

check w/ a local code official about reducing the size of the stack at the top. generally, they are pretty large at the top. i think 3" is a minimum. btw: do you have your own septic, or are you on a city sewer? if on your own septic, avoid the garbage disposal like the plague.

 

[oodssoo]

Though you did not answer my question, I still thank you for taking a bit of time to respond to my post/question.

My question is specifically on the stack order of the drain lines per their specific purpose.

As for the Air Venting subject (in case any of you are wondering), I will use an Air Admittance Valve (AAV) for the kitchen sink/dishwasher, while I will vent out through a 2" air vent pipe for the Vanity/Lav and Washer drain.

 

[AndyGump]

I don't think the order would matter in the least to your system.

Andy.

 

[oodssoo]

What about combining all three drain lines into one 2" drain line? Wouldn't this solve my problem?

 

[AndyGump]

I think that you should not put three 2" lines into one 2" line.
Should be a min. of a three inch line they feed into.

Andy.

 

[oodssoo]

I meant 3". Typo sucks!

 

[TheEplumber]

Hi,





(What I am looking for is wether the "stack" order I have drawn is adequate)




Thank you in advance.

The answer is no. If you want more info as to why- you need to supply more info. Such as- other vents, length of trap arms, etc.
You also need 1/4" per ft grade..

 

[mr leak]

odosso regarding drain venting

you have 5 drain fixture units Washing machine 2 sink with disposal 2 lav 1

slope must be 1/4 inch per ft and is limited on distance but a 2 inch vent is fine

 

[hammerlane]

I don't think the order would matter in the least to your system.

OK...Andy "Thinks" the order doesnt matter??? Ask your local building inspector if a major over a minor would not matter.

Then you have your answer.

 

[Javiles]

The answer to your question is no.. if your are discharging a washing machine that needs to go on bottom if dish washers then on the kitchen sink disposal or tail piece needs to be air gaped and trapped that stack is over loaded if in 2 inch and if using an AAV min 3 inch on a washer vent and drain. again that's under my code. also must have a clean out on that stack.

 

[oodssoo]

The answer to your question is no.. if your are discharging a washing machine that needs to go on bottom if dish washers then on the kitchen sink disposal or tail piece needs to be air gaped and trapped that stack is over loaded if in 2 inch and if using an AAV min 3 inch on a washer vent and drain. again that's under my code. also must have a clean out on that stack.

Sorry, Javiles, but I don't quite understand your statement... Can you please reword what you said?

I think you're saying that the washer needs to go on the bottom, the kitchen sink with disposal, then the vanity go on the top?

On the note of venting, I have the option to vent straight up into a 2" vent pipe or installing 3 aav's. Though, I think I will go the old fashion way of pipe venting...

 

[Javiles]

C on top B center A at the bottom as per your drawing.

This is what the code wants a mechanical discharge at the bottom of a gravity drain. and then it would be lavatory sink above a line discharging solids which would be your disposal. plumbing systems are designed to self cleaning, you always want clean water up stream of a solids discharge. also like others have mentioned length of those waste arms are important. if your in the south east your probably under the IPC thats the one we are under but we also have the south Florida plumbing code which covers areas not addressed under the IPC. should check with your local building official. hope this helps.

 

[hammerlane]

information given...has it been received??

 

[oodssoo]

C on top B center A at the bottom as per your drawing.

This is what the code wants a mechanical discharge at the bottom of a gravity drain. and then it would be lavatory sink above a line discharging solids which would be your disposal. plumbing systems are designed to self cleaning, you always want clean water up stream of a solids discharge. also like others have mentioned length of those waste arms are important. if your in the south east your probably under the IPC thats the one we are under but we also have the south Florida plumbing code which covers areas not addressed under the IPC. should check with your local building official. hope this helps.

Thank you, everyone that have taken time to respond to my post since the start.

I have revalidated and reviewed the 3-pipe stack configuration approach and have decided to go with a 2-pipe stack configuration. It only appears to be more feasible from the stand-point of how the pipe would fit both through the studs and at the drain stub-out - two 2" pipes would be best while staying in the proper drain heights (i.e. 14" for kitchen sink with disposal, Lav/Vanity at 18", etc.). These three fixtures will be on the same wall from left to right toward the 3" drain pipe with an air vent as drawn in the sketch.

Please take a look at the drawing that I have put together, and check my knowledge. I am open for constructive criticisms and suggestions, as some of you truly have been great and thorough in helping me.

Thank you again in advance.

 

[Javiles]

over Kill on the venting, double trapping, exceeded lengths on waste arm. what you have is not to code and will cause multiple problems. i will draw you a couple ways that may work for you. unfortunately you can not pipe around your framing, you have to frame around your piping. if you can post a drawing of the floor plan showing distance from the stack to fixtures and in between each other.

 

[oodssoo]

over Kill on the venting, double trapping, exceeded lengths on waste arm. what you have is not to code and will cause multiple problems. i will draw you a couple ways that may work for you. unfortunately you can not pipe around your framing, you have to frame around your piping.

After you pointed that it's over vented, I do see that as well. Would an AAV be best in this case?

Would you mind, also, share your thought on "double trapping"?

Also, how do you figure that the waste arm length was exceeded?

I look forward to your drawing, Javiles.

Thank you again for your help on the matter.

 

[hammerlane]

Would you mind, also, share your thought on "double trapping"?

Follow the flow of water from the kitchen sink. It has to go thru two traps.

 

[hammerlane]

also make sure the fitting circled in green are sanitary T's not Wyes with a combo