In-Slab Drain -- Sanity Check

Discussion in 'Plumbing Forum' started by wraezor, Nov 4, 2016.

  1. Nov 4, 2016 #1

    wraezor

    wraezor

    wraezor

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    Hey guys,

    I'm getting close to having my inspection (Alberta, Canada) for the below-grade plumbing and I'd like to get some of you fine folks to double-check my work. Some of it (the parts that are already in use) are cemented, but some of what you see is just dry-fitted.

    There's a lot going on in a pretty small space. There will be a wall almost bisecting the picture. Bathroom on right, Laundry / Furnace room on left.

    [​IMG]

    Some comments:
    - Backflow preventer is at where the drain exits the house.
    - There is a roughly 1/4"/ft slope throughout the horizontal.
    - The vertical stack, the vent at the shower drain and the stub for the basement kitchen will all be inside the future 2x6 wall, with access panels to the cleanouts.
    - The tub drain and overflow are not at the right height...it will end up much closer to the bottom of the picture once it is trimmed.
    - The 1 1/2" vent are going to be attached to the main stack above the overflow level upstairs.
    - All the fixtures (except for the toilet) have p-traps.
    - The center of the toilet flange will be 12" from the finished wall and the tub drain will be setup for a 60" x 30" tub.

    One of my concerns is the 180 degree turn for some of the pipes. I know it's not idea, but is it strictly forbidden, or does it depend on the inspector/locale?

    The other concern is venting. I hope I have adequate venting, but I could be wrong. I'm not 100% clear on those requirements. The basement kitchen line will have it's own vent closer to the end.

    Anything I should change or consider before cementing up the rest and booking an inspection? Thanks in advance.

    Here's the same picture without labels and also another.
    [​IMG]
    [​IMG]
     
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  2. Nov 4, 2016 #2

    nealtw

    nealtw

    nealtw

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    Frodo should be along so I will leave those details for him.

    I don't know what code is but out here, the pan under the water tank and the dribble valve feed the trap below the floor.
     
  3. Nov 5, 2016 #3

    frodo

    frodo

    frodo

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    .....................add a vent after the back water valve /before the toilet

    tub looks like 1.5..needs to be 2''

    move d.combo back, to many turns, paper will cause clogs

    0TafX0r.jpg
     
    Last edited: Nov 5, 2016
  4. Nov 5, 2016 #4

    cmccomb

    cmccomb

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    Is there a way to finish that out to where you don't have to cement it in that way you can get back to it if need be? You pour cement and it's not right you're in for a world of sweat
     
  5. Nov 5, 2016 #5

    wraezor

    wraezor

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    Thank you for the feedback, sirs. May I get some clarification on the comments.

    - What part of the tub drain needs to be 2"? From the p-trap on? The drain/overflow assembly I bought is all 1 1/2".

    - You suggest another vent down from the toilet. Doesn't the 3" vertical stack to the roof provide that as well?

    - And sorry, what is the d. combo?

    Thanks.
     
  6. Nov 5, 2016 #6

    frodo

    frodo

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    ....................

    Untitled.jpg
     
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  7. Nov 7, 2016 #7

    frodo

    frodo

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    sorry, did not have time for a lengthy answer, I have been busy
    the double combination in your picture has a 90 degre fitting attached to it and a 45 to pick up a toilet,
    WAY to many bends you are allowed up to 135 degrees before a clean out is required to claean out the line you are at 225...
    altho you are legal. you are into what i call not a good practice.

    to fix it,

    move the combo to where the combo for the upstairs is [switch spots]
    you will have to knock the dirt off that corner..but, you can handle it.

    also..you need a vent BEFORE the toilet. and the waste stack for upstairs is a waste stack, not a ven.
    so add a vent.

    what you should wind up with is 4x2 combo,4'' d wye, 4x3 combo
    in that order for the toilet and upstairs

    shower.jpg
     
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  8. Nov 12, 2016 #8

    wraezor

    wraezor

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    That's very helpful, thanks. I'm sorry I didn't take a better picture of what's going on on the other side. I can definitely make the change to get the additional vent line in, and connect into the toilet closer to the backwater valve as suggested.

    Maybe this top-down will be helpful regarding the other side of the layout. I'm really not sure how else I get the drain line (fixtures: floor drain, washer, upstairs kitchen) from the top of the photo into the main sewer line. Can I do that turn if I add another cleanout somehow?

    [​IMG]
     
  9. Dec 21, 2016 #9

    wraezor

    wraezor

    wraezor

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    Hi guys,

    Sorry to resurrect an old thread, but I've got one further hurdle to getting this solved. It is the washing machine.

    How do I tie it into my main sewer line?

    My main sewer line exits underneath the north exterior wall. I have a backwater valve in line, right before it exits under the wall. The same north wall (5 feet away) will have a washing machine. In order to connect to the main sewer line before the backwater valve, I need to drain away from the wall and then turn essentially 180 degrees.


    What is the best strategy for this? Can I put an extra cleanout flush with the floor to make the 180-ish degree turn kosher?

    Here's a simplified illustration:
    [​IMG]

    Thanks in advance. I really appreciate the help, since I feel I've gotten in over my head with this project.
     
  10. Dec 22, 2016 #10

    nealtw

    nealtw

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    You would likely want to add a vent too as your max is 60 inches ( I think)
     

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