Need DWV Guidance

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by Ryan_Z71, Feb 23, 2010.

  1. Ryan_Z71

    Ryan_Z71 New Member

    Messages:
    11
    Location:
    South Jersey, USA
    Hello everyone! I found this forum in trying to research DWV requirements. My situation is this: we bought a home with an unfinished in-law suite and had contracted to have it finished for my mother. Unfortunately, our contractor went under with the economy and took our money (we paid 80% over the time for work complete and materials), and then I lost my job of 12 years and have been bouncing around to what I can get for the past 18 months. Mom's health has deteriorated to the point where she cannot live alone (she has bone cancer) with a part time nurse, and we cannot afford any more help or assisted living, and my wife and I barely have money for groceries for the kids after the bills are paid.

    Only the suite's bathroom remains unfinished. Rough framing and electrical were completed, and we have all the materials that we had paid for (shower stall, tub, toilet, vanity, sinks, faucets, floor tile, drywall, and some lengths of 2" and 1.5" ABS DWV pipe). Basically, I need to finish the bathroom myself, and talked to the local inspectors who will work with me (I live in NJ). I do have construction experience having worked residential and light commercial (framing and finishing) in my youth to pay for college, but I am lost when it comes to DWV design and do have experience doing general plumbing repair and fixture replacements. Building office says I need a DWV diagram for a permit. Can you guys help???

    I've attached a schematic of the bathroom layout, and all that's in there for DWV is a 3" ABS pipe that runs at about 1/4" per foot slope over a ~25-foot length in the crawl space till it ties into the main 3" leaving the house to the street. Nothing at all is on that branch and it's capped. The house is a one-story ranch with a foundation crawl space and attic crawl space so I can vent as needed. I'm really lost with what the contractor's plumber had in mind to connect the new tub drain because the 3" line is directly below the drain center. The 3" cannot be moved anymore in the direction of the closet in the area of the tub because the heater plenum is there (ends about 14" off the new long, closet wall), but can be moved toward the exterior wall slightly (12-16") before other things seriously interfere, but then I can't see how to vent that drain.

    Thank you in advance for any help and guidance you could share with me.
    Ry

    Attached Files:

  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,647
    Location:
    Cave Creek, Arizona
    Even if we gave you a "generic" diagram, it might not fit your installation, since it depends on HOW far below the joists the 3" is located, and other factors we cannot tell from the drawing. The only way to decide on the "best" installation is to be there and actually see what we are working with. We can appreciate your financial situation, but like surgery, sometimes the best option is to leave it to an expert.
  3. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    This is a tall order sight unseen. They will want an isometric pipe diagram. Let me just list some basic points for starters:
    > All pipes must always slope downward at least 1/4" per foot
    > Vent pipes cannot be horizontal ( less than 45º) unless they are ~42" above floor
    > On a horizontal pipe, the vent cannot be taken off horizontally ( except see wet vent)
    > You will need to learn about fittings....long sweeps, wye on horizontal, sanitary tee on vertical, etc etc
    > Each fixture must be vented. Most codes allow a wet vent arrangement on a single floor bathroom group, which will make life easier.
  4. Ryan_Z71

    Ryan_Z71 New Member

    Messages:
    11
    Location:
    South Jersey, USA
    HJ, well after going the route of paying the pro and having them go under without finishing the work and paying for work never completed... I had 3 plumbers come look at it over the last month, and cannot find a way to pay for what they estimated - all within 10% of each other. I tried to ask if I could pay them for their help in putting together a diagram I could follow, but none were interested - "all or nothing and your loss" was the harshest comment from the one plumber who seemed like I wasted his time even though advertising free estimates... So, if I could honestly afford it, I would because I need to get my mother in here, but I believe I can do this with some help and the inspector should keep my straight.

    I have been studying this a little while and am familiar with the various plumbing fittings, just not sure I understand the "rules" of when to use a combi vs a wye, and so on. Where the 3" is capped, from the top of the pipe to the bottom of the closest joist is an 1-3/4". What kind of information could I provide to help make things clearer?

    Thank you!
  5. JohnnyR

    JohnnyR New Member

    Messages:
    12
    Location:
    Spokane
    Hey Ryan

    Can you or have you used Google SketchUp? Its free and in a couple of days you can put together a pretty accurate model of the project, then maybe some of the pros can help. Look around these forums for discussions on using sketchup, it pretty easy and lets you visualize the "big picture", I'm far from a pro, but I've seen this forum in action, and if these guys have enough info they definitely help. Here's a link to the program, just get the free one and watch the getting started vids. Good luck, Im working on my model too. :D You'll find this forum is wonderful and full of very helpful guys/gals.

    P.S. you can download scale DWV fittings and pipe so you can see how they will fit in your walls etc.

    Anywho, Good luck man.

    JohnnyR
    Last edited: Feb 24, 2010
  6. Ryan_Z71

    Ryan_Z71 New Member

    Messages:
    11
    Location:
    South Jersey, USA
    Johnny,

    Thanks. I really don't know if I can squeeze in the time to learn it. I work two jobs during the week and another on the weekends right now and try to still spend time with my wife and twin 4 year-olds.

    If no-one really wants to dive in, can someone at least point me to a good book where I can learn about the design basics? If I can get it at the public library, even better.
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,647
    Location:
    Cave Creek, Arizona
    I will give you one experience I had with a friend/customer who relied on a drawing of a DWV system to do it himself. He went to the city, and they gave him a "perfect" isometric drawing of the system he needed, and he installed it exactly as HE saw it in the drawing. Then he asked me to make the connection into his existing system so it could be inspected. When I saw how he had put it together, first I had to laugh a bit, then tell him I would have to toss it all in the scrap heap because it was COMPLETELY inaccurate. I told him the plumbing inspector would have been laughing so hard he might not have been able to write everything he had to on the rejection tag. He looked at the diagram and saw it the way he thought it should be, but did not realize that was NOT the way the drawing was showing it. For that reason, I NEVER try to tell someone how to do a complete system, because they will see and hear it, but may interpret it completely differently than intended.
  8. Ryan_Z71

    Ryan_Z71 New Member

    Messages:
    11
    Location:
    South Jersey, USA
    Isometrics

    hj,

    I can read plans without confusion. I trained as a mechanical draftsman when Rapidograph pens were the staple, and a draftman's best friends were his T-square, triangles, and eraser shield. Spent many years after working part-time nights and weekends for a fab shop preparing their shop drawings. Only wish I had learned CAD because that would help me now financially. No-one needs a draftsman who can use French curves and explain an "H" versus "HB" pencil...

    I could draw an isometric for this with little issue if I knew the proper rules of venting and what fittings are right and which are not...

    Ry
  9. tuffy

    tuffy New Member

    Messages:
    8
    Location:
    British Columbia
    here is a top view of what you may be able to do if local code permits. use a double tee to connect the two sinks and this will wet vent the toilet and shower through a double y fitting. check with inspectors to see if local codes permit this. then vent the bath on its own through the wall near its drain

    Attached Files:

  10. tuffy

    tuffy New Member

    Messages:
    8
    Location:
    British Columbia
    here is isometric. If you are not absolutly sure of how this goes together or if codes for your area dont allow this then you may end up spending more than it would cost to get it done professionally. once you glue together fittings they are basically garbage if an inspector tells you it is wrong. As HJ has said... you may not interperet this isometric correctly or some unforseen obsticle will make this not work correctly and you could end up with a lot of fittings for the trash heap and could end up paying a pro to do it anyway. Draw it out and take it to inspector to see if it even passes their codes.
    Keep trying different plumbers. You may find one that will just guide you
    good luck with this

    Attached Files:

  11. Ryan_Z71

    Ryan_Z71 New Member

    Messages:
    11
    Location:
    South Jersey, USA
    I wish I could thank you in person!

    Tuffy,

    I worked from what you provided and was issued my permit yesterday! All that was requested is that the shower be vented by itself. I went to the plumbing supply today and purchased the fittings and cement. I asked the inspector if there was any chance he'd be willing to review my piping in dry fit. While he didn't agree, he didn't disagree and said to call him when I get to that point...

    Thanks again for the help! I appreciate the time you took!!!

    Ry

    [​IMG]
    Last edited by a moderator: Jun 2, 2010
  12. Ryan_Z71

    Ryan_Z71 New Member

    Messages:
    11
    Location:
    South Jersey, USA
    Haven't been by in awhile, but a quick note following up. Thanks to Tuffy's guidance, I made a successful install only needing to add more support hangers and raise my vents above the roof an additional 6" (probably because of this past winter's accumulations) to get the approval.
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