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Pex or Pure-Core underground H2O supply

avion | Posted in General Discussion on May 26, 2009 12:01pm

Hello,
What would you recommend to supply water from a house to an unattached garage. This will be in a 48″ deep trench which will be shared with the return 2″ PVC (sched40) which will carry the waste back up to the house main which is hooked up to city sewer.
I am thinking 1″ Pex or 1″ Pure-Core. It is a 120′ run underground. Might be able to get by with 3/4″ but thought the cost difference would be minimal.

Thanks, Patrick

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  1. JTC1 | May 26, 2009 12:15am | #1

    Patrick,

    Welcome to Breaktime, filling in your profile will help with answers sometimes - this would be one of them.

    Not a plumber.

    That being said, around here, DE, if we run both supply and sanitary sewer in the same ditch 1) the sewer must be below the supply and 2) vertically separated by 24" (I think -- i.e., the supply is 24" above the sewer - not positive on dimension).

    This would put your supply pipe at 24" below grade -- my local frost line is 32" = trouble at some point.

    Would be worthwhile to check your local regulations.

    Others, more informed as to your pex vs pure-core question will chime in soon.

    Jim 

    Never underestimate the value of a sharp pencil or good light.
    1. avion | May 26, 2009 12:41am | #2

      Jim,
      Thanks for your quick reply.
      I am unfamiliar with the "profile" I could fill out, I will snoop further, this is all new to me.
      I am in Iowa, the frost line is 42".
      I thought the supply water could be above the waste pipe if I maintain a 12" separation in the trench, maybe this is not correct.
      Now that I think of it the trench would have to be 58" deep in order to maintain that 12" separation and have the supply pipe 42" below grade.
      I don't think the trencher I will rent can get below 48",I will call tomorrow.Patrick

      1. GregGibson | May 26, 2009 02:25am | #3

        In my soil, trenching twice would be a breeze - maybe not where you are. Great to be efficient, but two trenches would take care of the separation.I'd probably pop in a run of 1 inch gray conduit with a pull string - never know when you might want to wire a security system out there.Greg

        1. avion | May 26, 2009 02:50am | #4

          Greg,
          Thanks for your input. Trenching may not be too bad here, more of an issue of tree roots rather than rock. Lets say I trench two separate trenches 48" deep, I am unclear as to how far apart they have to be. I have heard 10', that seems excessive. Also whatever the separation can they come together where they enter the garage or house?Patrick

          1. User avater
            bobl | May 26, 2009 03:06am | #5

            does waste have to have a slope in the ground.iirc inside a house it is 1/4 in per foot. 

            bobl          Volo, non valeo

            Baloney detecter    WFR

            "But when you're a kibbutzer and have no responsibility to decide the facts and apply the law, you can reach any conclusion you want because it doesn't matter." SHG

      2. JTC1 | May 26, 2009 03:20pm | #7

         

         

         

         

         

        I thought the supply water could be above the waste pipe if I maintain a 12" separation in the trench, maybe this is not correct.<<

        You may be right - local regulations vary. 

        >>I am unfamiliar with the "profile" I could fill out, I will snoop further, this is all new to me.<<

        Click on your screen name - avion - in this post (or any other) this will take you to a screen where you can create or change your profile - basic info about your location, etc.  Click on any other poster's name and see theirs.

        Jim Never underestimate the value of a sharp pencil or good light.

  2. PedroTheMule | May 26, 2009 06:39am | #6

    Hi avion,

    What would you recommend to supply water from a house to an unattached garage. This will be in a 48" deep trench which will be shared with the return 2" PVC (sched40) which will carry the waste back up to the house main which is hooked up to city sewer.
    I am thinking 1" Pex or 1" Pure-Core. It is a 120' run underground. Might be able to get by with 3/4" but thought the cost difference would be minimal.

    I'm not a licensed plumber but have done exactly what you are seeking to do and the inspector was pleased.....

    4' trench, pumped sewage with lift grinder from 50 gallon holding tank in shop through 2" pvc. Since a pump does add some pressure to the line, I tested it as you would a water line....I took it to 200 psi and was given variance to run drinking water in same trench by double sleeving the septic line inside of 4" pvc. The concern seemed to be with something puncturing the septic line and it getting into a similarly punctured water line. The idea of the outer pvc sleeve is to prevent the inner from being punctured. I used 1 1/4" pvc for my water....almost a 100' run...although the primary connection was only 3/4", the larger pipe offered far less resistance. I used gray pvc electrical pipe for my subpanel feed after backfilling 18", backfilled another 14" then laid in a pair of 3/4" pex, ran Cat5 for telco & Cat6 for network in one and a pull string in the other....who knows I might want fiber out there one day. Backfilled the rest.

    Pedro the Mule - I'm in deep dirt

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