Plumbing a kitchen double sink, with dishwasher and disposal


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Old 04-22-16, 02:12 PM
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Plumbing a kitchen double sink, with dishwasher and disposal

I have a double kitchen sink with disposal and dishwasher. I plan on connecting the outlet from the dishwasher to the inlet on the disposal.

i have 2" ABS coming out from the floor.

The kitchen sink is on a peninsula.

The current design is 2 sanitary tee's stacked one on top of each other, each with with a trap adapter for each respecting trap from each sink drain.

Is this the best design?

It currently vents out the top of the sanitary tee into a 1 1/2 roof stack.
 
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Old 04-22-16, 02:28 PM
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Hello!!! Welcome...

Is this the best design?
No.. Its one trap per fixture per code..

You need to do a side waste ..

[ATTACH=CONFIG]65379[/ATTACH]
 
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Old 04-22-16, 02:36 PM
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everywhere i look the disposal side has its own trap. Each goes into a vertical stack that i mentioned consisting of two sanitary tee's one on top of each other.
 
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Old 04-22-16, 03:13 PM
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everywhere i look the disposal side has its own trap. Each goes into a vertical stack that i mentioned consisting of two sanitary tee's one on top of each other.
Well where are you looking Andy?

Im telling you what code is as I know it..

You can hook it up anyway you want.. Its your house..

I just answered your question is all..

Is this the best design?
No and not to code!!!!
 
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Old 04-22-16, 03:33 PM
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Mike is correct. One trap, just as his drawing shows.
 
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Old 04-22-16, 03:42 PM
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my current waste line goes through the floor. It is 2" ABS. I plan on cutting it off at the bottom and re-doing to fit my new deeper sink. I need a design that ends with going straight into the floor, and also incorporate a vent line before it goes to the ground.
 
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Old 04-22-16, 03:52 PM
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It currently vents out the top of the sanitary tee into a 1 1/2 roof stack.
Thought you said it had a vent. Its not too hard to figure out what you need to do. In Mikes picture, where the number "5" is, that's where your vertical sanitary tee would be.
 
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Old 04-22-16, 03:57 PM
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Right OK, so 5 would literally be a sanitary tee, with a 2" bottom, 1 1/2" for the trap side, and then 1 1/2" on the top which leads to the vent, correct? I've seen this model a bunch online, but when i look around my city at both existing and NEW construction, it seems that EVERYONE has a 2 trap system. They have two inlets into the wall, one on top of the other.
 
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Old 04-22-16, 04:15 PM
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The code can sometimes be interpreted, but it's best to stick with the plan. One san tee.

IMO, it's easier to work with one tee and one trap, and I hook up a lot of sinks.
 
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Old 04-22-16, 05:17 PM
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I think this is what Mike means. Wait for confirmation.

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Old 04-23-16, 09:33 AM
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I've seen this diagram before, but the feedback that i've heard is that the drainage isn't very good, this is why i have been seeking a two trap system.

Garbage Disposal Plumbing
 
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Old 04-23-16, 10:37 AM
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Below is a sink I hooked up. I like to hook up all sinks like this if at all possible.

Notice the disposer elbow goes down into a baffle tee, which is also where the other bowl ties in.

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Old 04-23-16, 10:42 AM
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Can anyone think of why one would use a two drain/trap design vs the singular approach that has been given many times? In my city, all the new construction seems to use a two drain (vertical stack) design
 
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Old 04-23-16, 10:57 AM
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IF the two drains are installed at the correct height and at the correct angle, then connecting the plumbing would be easier. This never happens to me when I walk in and just simply connect two traps. It usually turns into a pain.

The picture I posted is ideal to me. If I see this trap set-up, I know I'm going to have a good day.
I want to make this easy on you.
 
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Old 04-23-16, 11:11 AM
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Some municipalities require that a commercial or restaurant garbage disposal have its own trap. This is never a requirement in residential. 2 traps is just a needless congestion when one will do.

Most places in the US likely follow the IPC 2012 as the basis for their local code... 1002.1 Fixture traps. Exception 2.

You never said where you are located in Missouri. Maybe you've got an inpector that has his head in the sand... or maybe you're in an area where there is no code and it's a free for all.
 
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Old 04-23-16, 11:17 AM
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2 san tees on top of each other is a wet vent.. wet vents have not been allowed for sometime..

I cant fathom that you see this in new construction..

Show me a pic if you can...
 
 

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