Island vent for L-shaped kitchen

Discussion in 'Toilets and Sinks' started by branimal, Jun 8, 2019.

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  1. Jun 8, 2019 #1

    branimal

    branimal

    branimal

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    I'm putting a sink on the L of my kitchen. I drew up a rough sketch of what I think the rough plumbing should be.

    I cannot run my drain and vent under the cabinets of the kitchen as in a traditional island vent setup b/c my attachment point to the drain line is 6" above the finished floor. The drain pipes will be 2".

    I have a few questions:
    1. Does this setup work?
    2. Can I downsize the vent pipes to 1 1/2"
    Screen Shot 2019-06-08 at 5.35.39 PM.png IMG_5122.JPG
     
  2. Jun 9, 2019 #2

    breplum

    breplum

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    For UPC jurisdictions: you can run a 2" trap arm 5', or a inch and a half trap arm 3'-6".
    The drawing you made is not proper on many points.
     
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  3. Jun 9, 2019 #3

    branimal

    branimal

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    Yep - I forgot I could run the trap arm straight a certain distance b/f I connect to a sanitary tee in the wall. The distance I need to cover is less than 5'.

    Thanks.
     
  4. Jun 9, 2019 #4

    frodo

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    a 2'' trap arm will require a 2'' trap

    you can reduce to 1 1/2'' on the vertical

    i strongly suggest installing a 2'' wye next to the the ptrap with a clean out in the wye
     
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  5. Jun 9, 2019 #5

    branimal

    branimal

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    If I’m using cast iron pipe, can I use a 2” cast iron cleanout tee like this?

    75445B92-1D8D-4468-A875-EFA5D1627E73-2366-00000051B93D995F.gif
     
  6. Jun 9, 2019 #6

    frodo

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    that is used in the vertical like at the base of a stack
     
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  7. Jun 9, 2019 #7

    branimal

    branimal

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    Ok I’ll use a pvc wye with cleanout adapter.

    IMG_5126.jpg
     
  8. Jun 9, 2019 #8

    frodo

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    it would be a whole lot cheaper
    is there any reason you are using cast?

    I know you have to if the building is 4 story or taller [fire codes]
     
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  9. Jun 9, 2019 #9

    Zanne

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    I can't tell from your drawing if the 90 elbows are all for vent or if they are for drains, but if any 90s are for drains, they need to be long sweep 90s and not the short vent 90s.
     
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  10. Jun 10, 2019 #10

    branimal

    branimal

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    Can I can point the p-trap toward the wall so as to avoid one 90 degree turn?

    When I did my first reno, it was in a 6 story building in NYC which required cast iron. So I got experience using cast. I found working with PVC a little difficult b/c once you set an angle on a fitting you can't redo it without cutting it. On the current project (3-family, 3 story) I used cast for all my drains, and PVC for my vents. I'm a bit more comfortable with working with PVC now. So I will use more PVC going forward.

    I find that PVC is a bit noisy when draining and this kitchen drain run is long run. I'll start it off with a PVC trap and PVC cleanout wye and then convert back to cast.

    Plus I have a sh*t-ton of cast iron. I bought $450 worth of brand new cast iron from a metal scraper at a new construction site for $25. 4", 2" no hub pipe and 3/4" gas pipe with the red sleeves still on them.

    @Zanne - yes I'm going to use longer 90's (I believe they're called short sweep 90's in the cast iron world) or 2 45 degree elbows where ever I can fit them in.
     

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  11. Jun 10, 2019 #11

    Zanne

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    Are you using glued fittings for the trap under the sink or are you using the slip joint kind? You can use slip joint so you can adjust the angles.

    Yes, you can point the trap where you want so long as it has sufficient space. It's probably better to aim it toward where you want it rather than having to use long sweeps. The more straight runs you have, the less obstruction & the easier it is to snake out. You can get P-trap with trap adapter (goes from the slip fit to the solvent weld type of PVC) as kits at big box stores. The slip fit isn't as sturdy as the solvent weld so I've found it is more likely to crush in when trying to use a cutter so it can be a pain if you're not used to working with it. Kitchen sinks usually have 1-1/2" drains so you could get that sized kit & expand up to 2" later in the run. I'm trying to figure out where your vent would be-- is it going to be in the wall?

    Sounds like you got an awesome deal on the cast iron stuff! I take it you're running a separate water line & drain for the dishwasher? I know a lot of people put the dishwasher directly next to the sink & use the sink's drain. My family got a freestanding dishwasher that has to be pushed over to the sink, have an adapter attach to the faucet & hot water turned on at the sink. It then dumps everything into the sink when it drains. It's such a royal pain that we haven't actually run it in years. In retrospect, I wish we'd gotten a built-in & put in a small island to make up for the lost cabinet space.

    Just to be clear, your sink is on the peninsula (like an island but attached to other cabinets) right?
    Red line represents the drain path?
    Is your vent for the sink going to be in the wall?
    Frodo can probably tell you more about the vent length requirements because my brain is still in zombie mode right now.
     
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  12. Jun 10, 2019 #12

    breplum

    breplum

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    "a 2'' trap arm will require a 2'' trap " follow the code.
    I suggest you use no-hub type couplings at the plastic 2" trap to make servicing easier. In other words, use a union 2" plastic p-trap and a NH coupling at the cabinet wall, and slip joint or NH type adapter coupling at the sink vertical tailpiece.
     
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  13. Jun 10, 2019 #13

    branimal

    branimal

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    Vent connection is going in the wall that the peninsula attaches to.

    Yes sink is on the peninsula. I might move the dishwasher to the peninsula to the right of the sink.

    Dishwasher drain will connect to the tailpiece off the sink. They make special tailpieces with a "tee" in it. Hot water for the dishwasher will tap off the sinks hot water supply.

    MY parents had one of those freestanding dishwashers growing up. It was better than washing dishes. 1980s for ya. Lol.

    Red line is the drain path.
     
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  14. Jun 10, 2019 #14

    Zanne

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    How much space is between the sink & the wall?

    Is there a garbage disposal?

    The tailpiece fitting was what I was visualizing when I was wondering how you were connecting your dishwasher. It would probably be easier to have the dishwasher next to the sink- looks like there's room for it off to the right of the sink. The cabinet between the sink & where the dishwasher is in your drawing could be accessed from the other side of the peninsula with a door, leaving room for the vent pipe to run to the wall. We did something similar on our kitchen peninsula but we put the stove on the peninsula instead. In retrospect, I wish our sink was closer to the stove.

    Have you considered putting the sink where the dishwasher is in the sketch? and moving the dishwasher to closer to where the sink is? That way you can easily fill pots from the sink & then put them on the stove & also easier/closer to put stuff in the sink. Then you can rinse stuff in the sink & stick it in the dishwasher.
    Another option would be to put a diagonal corner sink base cabinet in & put the sink at an angle. This way it would be closer to the wall, closer to the stove & it could make better use of space. The dishwasher could still be on the wall where you want it & be closer to the drain. You could still put a door on the backside of the base cabinet to access the plumbing if there's not enough room from the front.

    Another alternative would be to install the sink at an angle on the corner an

    We had the dishwasher in the 80s as well, but we never had one that would clean the dishes without them being scrubbed/washed first. I often had to rinse anything that was put in the dishwasher bc it left a film/scum on the outside or just didn't clean so I ended up just using it as a drying rack. LOL.

    As a weird side note, are you going to have upper cabinets above the peninsula or is it just going to be open?

    Questions for Frodo about island/loop vents:
    1. Does the lower pipe have to go under the floor/cabinet or can it just be run under the other pipe?
    2. Does the loop vent have to go to a vent within the same distance parameters as a trap arm?
     

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    Last edited: Jun 10, 2019

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