Replacing old cast iron

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by m.herndon, Nov 5, 2012.

  1. m.herndon

    m.herndon New Member

    Messages:
    1
    Location:
    Fayetteville, NC
    I am about to buy a house that was built in 1920. I am on a limited budget and we are going to be remodeling the house so I am trying to do EVERYTHING I can myself, and hire out the rest. I am not a plumber by any means but I feel I could tackle small jobs here and there. I was in the crawl space and took some pictures of the existing plumbing. Some of the pipes were crumbling when you touch them; others had cracks in them. I believe that they are drain lines, including a major drain line running to my septic tank. My question is, can I replace them with PVC or ABS pipes of the same diameter? I was told to basically assemble the pipes in the same fashion and lengths as the originals, and when I cut the old ones out, use a fernco coupler and attach the PVC to the cast iron. Should I cut the existing traps and t's out and replace them with the PVC or ABS? I know that I need to maintain certain slopes and such, I am just not sure of the route to take when replaceing these!

    \/Main drain pipe leading to septic. About a 4'6" crack down center
    [​IMG]

    [​IMG]

    [​IMG]

    \/This one has a crack on the underside of it.\/
    [​IMG]

    Can I cut the fittings off and install new ones? What do you think would be the best route for these as far as materials and where to cut? There are only a couple places that are bad so I dont think I need to have a plumber re-do the entire house.
    Thanks for all the help!
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,268
    Location:
    New England
    Cutting cast iron can be a pain. The way it was done may no longer meet current codes, so a direct replacement may not be the best choice. But, yes, you can replace it with abs or pvc. Use a no-hub connector above ground - this is thin rubber sleeve with a metal reinforcement band around it, and screw clamps to tighten it down.
  3. hhplumbing

    hhplumbing New Member

    Messages:
    13
    Location:
    Victoria, BC
    Hello m.herndon,

    Cast Iron can be a pain like Jadnashua said but what I think you should be doing, if like you said, you don't need to replace everything is start with the worst runs and replace the Cast Iron pipe with ABS pipe as it's the same diameter. Use a Fernco coupling where the cast is reusable. When it comes to the fitting(s) your going to have to check your local code and see what your allowed to do. After you find out, use ABS fittings to replace the cast.
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,049
    Location:
    Cave Creek, Arizona
    Deteriorated cast iron may NOT cut with a snapper, but may crush instead.
  5. godsplumber

    godsplumber In the Trades

    Messages:
    8
    Location:
    California
    great pictures. with limited money if its not broken don't fix it approach. Fernco's (all rubber/no metal shield) are used for only when buried by earth. must use approved shielded coupling which will be labelled cast to abs, or cast to copper etc. I used a skill saw with a $3.00 metal blade to cut cast iron, where my saw would fit. made clean cut and didn't crush like my snap cutters did. Also 4" grinder worked good too.
    Check out the code where it talks about "rat proofing" be sure to seal holes while your there and use proper fittings.
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,268
    Location:
    New England
    And, I'll say it again...what is there now, while it may have worked, may NOT meet current codes, and a direct replacement may not cut it with the local inspector! If you're going to go to the trouble of replacing large chunks, you may be required to bring it up to current codes. The line between a repair and a remodel can get dicey depending on where you are.
  7. Gary Swart

    Gary Swart In the Trades

    Messages:
    7,386
    Location:
    Yakima WA
    Might be worth the expense to have a plumbing contractor deal with this. You're trying to save money I realize, but you could go through a lot of work and time and then find out what you did will not pass inspection and have to be redone. This is a job that may look fairly simplistic, but is actually has pitfalls that are not apparent to the novice. Just something to consider.
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