Replace cast iron drain pipes.

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Big John, Dec 25, 2009.

  1. Big John

    Big John New Member

    Messages:
    3
    Location:
    California
    Water bubbles up through slab near vent pipe in wall. I can see down about 12 inches with a light. As we have a lot of ground water and the CI is about 50 years old I expect to have to cut the slab and replace any damaged CI and refill the trench. Should i use sand or rock to refill? The dirt we have is clay like and moist all the time. The CI pipes in several nearby homes have deteriorated and had to be fixed. I'm assuming the worst case and preparing for the dig.
  2. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    You should bed with sand but the water issue should be addressed when you cut the concrete. You need to provide drainage beneath the slab or the pipe may settle unevenly.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,056
    Location:
    Cave Creek, Arizona
    pipe

    Describe what you mean by "water bubbles up? Water does not bubble up unless it is under pressure of some kind, so either you do not have a drain pipe problem, or you do but also have a plugged drain line to go with it. The only way to tell definitely if you have a problem with the piping is to have a video inspection. It will show you what the pipe's condition is, and also WHERE the pipe runs under the floor, because if one section is bad, it should ALL be bad.
  4. Big John

    Big John New Member

    Messages:
    3
    Location:
    California
    Thanks for the information. I will find out more when i cut the slab and get into the project.
  5. Big John

    Big John New Member

    Messages:
    3
    Location:
    California
    You are right about the water "bubbling up". It happened when the main was plugged up further down the line and the dish washer was running. When the clog was cleared through another clean out the drain water stopped coming up through the slab. I tried to get a video and a company tried but it could not be done because "the line was filled with too much sludge and it had to be pressure cleaned first." I will try again to get a video of the line which I agree is the only way to really know what is going on. Thanks for your advice. This is going to be very interesting. I expect to be eating out a lot while this is getting fixed.
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,269
    Location:
    New England
    The line may need to be entirely replaced. It sounds like it may not be pitched properly if it is full of sludge. This can cause standing water in the drain, and can corrode things even faster. Could be a dip, belly, or crown.
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