Septic line DIY replacement

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by Smith333, Sep 28, 2009.

  1. Smith333

    Smith333 Member

    Messages:
    108
    I recently removed a large concrete patio and plan to replace it with a ground-level deck. The septic line that services the house runs under this area, and I've decided to replace it because it is 35 year old cast iron, it has a leak inside of the foundation wall with several roots in the pipe at that location, it isn't very deep (30" at most), and is convenient to do at this time.

    The line leaves the house at two points and combines near the septic tank. Currently, the only cleanouts are in the basement, which would make a big mess if they ever had to be used.

    I propose to replace the cast iron with SCH40 PVC. All joints will be solvent weld except for those denoted by the blue line, which will be sheilded connectors. I will dig around the cast iron pipe, but not under it, to retain the proper pitch and bedding. I want to back fill the pipe with sand, followed by some class-2 fill , then native rocky-gravel fill on top of that.

    I plan on adding cleanouts at the locations denoted by the red circles.

    Does this sound like a good plan? I checked Wisconsin code, which indicates that septic lines don't need frost protection within 30 feet of the foundation.

    Thanks in advance.

    Attached Files:

  2. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    It looks good to me. Just make the clean out in the center a two way so it can be snaked in either direction.

    John
  3. leejosepho

    leejosepho DIY scratch-pad engineer

    You might run the far line over to the close one either inside or just outside the basement wall and save some digging.
  4. Smith333

    Smith333 Member

    Messages:
    108
    johnjh2o1 : That's a great idea, I'll be sure to use that fitting.

    leejosepho: I'd like to do that, but the basement is finished. Also, other utilities in this area make moving the pipe closer to the house rather impractical.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,653
    Location:
    Cave Creek, Arizona
    pipe

    DO NOT USE A TWO WAY CLEANOUT FITTING. Use TWO cleanouts at the building, and eliminate the one in the middle of the line. Can you angle the right hand line on a 45 after it leaves the building to make a more direct flow?
  6. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    What is wrong with a two way? He has two clean outs at the building.

    John
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,653
    Location:
    Cave Creek, Arizona
    Two way

    What is wrong with a 2 way? Just that if you REALLY need that cleanout it will be because it is full of water and getting your snake to go the proper direction can be a pain. The only "good" two way cleanout is one in the scrap bin. Why would he need it since he has cleanouts at the house which will snake past that point?
  8. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    To you it may be a pain but we have tools that make it go in the proper direction. Why must you play the know it all with just about every post? I think that we need a moderator for the moderator.
    John
  9. Smith333

    Smith333 Member

    Messages:
    108
    I've completed exposing the line, and this is what I've found:

    - It is composed of 5 ft sections of XH cast hub connected w/ rubber inserts.

    - It is completely broken off just outside the foundation where it leaves the house closest to the septic tank (see pic). The allignment is still intact, but it has separated about 1/8".

    - The far end of the line is not square to the building.

    - The PVC portion is a patch job from 10 years ago when a backhoe struck the line while replacing the electrical service.



    Is it safe to assume that the break is due to the out of whack allignment?

    As shown in the picture, I ran a string line that is parallel to the house. I'm guessing my life will be a lot easier if I correct this problem during replacement? Any tips or comments would be greatly appreciated.

    The parallel run is about 50 ft, and 9 ft from the house.

    [​IMG]

    [​IMG]
    Last edited by a moderator: Oct 3, 2009
  10. Smith333

    Smith333 Member

    Messages:
    108
    Finally got it changed out today, and it went pretty well. As HJ suggested, I changed all the 90's to 45's. I used shielded fernco couplings and added 3 cleanouts. As you can see from my pic, I had my own "funky" allignment issue at the 2nd wye, but everything went together alright. It wouldn't be a DIY job without a few screwups. LOL

    [​IMG]
  11. Smunderdog

    Smunderdog New Member

    Messages:
    19
    Location:
    Indiana
    For those of us playing along at home...is there a reason you used Fernco couplers to join the straight runs of pipe? Is there a benefit to using those instead of couplers you would glue?
  12. Smith333

    Smith333 Member

    Messages:
    108
    There's other threads from a while back that discuss how solvent weld joints underground can break over time if the ground shifts. I'm not sure how likely such an event is, but I tried to avoid solvent weld joints where possible.
  13. Lakee911

    Lakee911 I&C Engineer (mostly WWTP)

    Messages:
    1,328
    Location:
    Columbus, OH
    Looks nice! :)

    Maybe everyone doesn't have those tools. If I was paying a plumber by the hour on a holiday Sunday at 3AM when the company is at the house and he can't get his snake in the hole to go the right way, I'd be pretty pissed at myself for skimping and putting in that 2-way clean-out.

    I think we just need self-moderation. :)
  14. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,143
    Location:
    South*East
    The tool is a piece of PVC pipe with a 45 on the end to guide the snake in the right direction. All it takes is a little commonsense.

    John
  15. Smith333

    Smith333 Member

    Messages:
    108
    I decided to put the cleanout at the far end instead of the middle, which would have been under the deck. This way it will always be accessible. There's also another cleanout right next to the foundation.

    [​IMG]
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