I noticed cracks in the walls getting larger and called someone to check on the foundation. The foundation is fine (it's previously been repaired) but the center of the house is sinking. I plugged the outside drain line and did a leak test, and the water level in the shower drain dropped pretty quickly, so I'm pretty sure there is a leak.

My house was built in the 60s and I'm told it should have iron drain pipes. I assume the problem is a pipe running through the foundation to the outside sewer line. What is going to be involved in replacing the drain pipes? Am I going to have to tear up the floors all over my house to get all of them?

EDIT: I should add that this is Texas, so I don't have a basement.

  • You might not necessarily have cast iron sewer pipes. So called orangeburg pipe was quite common during 60s. That pipe is pretty much cardboard and will be in a bad shape after 50 years – Vitaliy May 20 '13 at 4:47
  • Are clay drain pipes common in your area? They are notorious for getting tree roots growing in them and causing leaks. – auujay May 20 '13 at 16:35

Vertical sections of cast iron rarely need replacement. Horizontal ones do. I would get a quote(s) from a plumber that does/has connections with sewer line installations.

They should start with a in-line camera review.

Chances are most of your work will be in the (hopefully you have) basement and yard to the main sewer, but again, don't panic until someone runs the camera

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I literally just finished this. I had black cast iron via 1967.

If you have all original black iron pipes then yours are about end of life - they last about 50 years without issues. They literally rust from the inside and it reduces the amount of space for things to drain in your pipes and the rust allows things like hair to snag and start clogs... When I took mine out more than half the pipe was restricted - all of them.

If you are going to dig up your basement then I would replace everything that is iron.


  1. Figure out where your pipe meets the sewer line to the street.

  2. You will have black iron under your foundation but usually it will meet clay/pvc/whatever right outside your house. You may need to dig outside your house too. Either way you need to have a pretty good idea on the exit path.

  3. Starting from where the main stack hits the ground - you need to jackhammer the concrete and remove the dirt above the cast iron. You will need to actually dig a few inches below the pipe - don't break it.
  4. Follow this until you hit the wall or the city sewer line.
  5. Cut out cast iron - you will probably cut about 2-3 feet above ground on the stack.
  6. Connect new PVC. Also you may want to think about if you need exits for the basement. Doing roughins for a basement bathroom is easy at this point so that is something you need to think about. Steps 5-6 need to happen in the same day so you can go to the bathroom.
  7. Get it inspected... Inspectors need to see it at this point and usually not before.
  8. Fill with dirt and reconcrete.
  9. Replace the rest of the cast iron - toilets, showers, sinks, whatever
  10. Finish inspections.

This is not rocket science. You have the lines already there. Unless you reroute something then you will basically make the exact cuts that you took out and just replace material. If you do hire a plumber you can save a TON of money doing the jackhammering and concrete work - which is just labor. A good plumber (+helper) can do steps 5-6 in 3-4 hours and step 9 in a full day.

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  • I don't have basement... – noah May 20 '13 at 13:30
  • Same thing minus basement then... You can either knock out the floor to the exit or close it off and have a brand new exit. You are in for a lot of work and fixing of flooring. Sorry. – DMoore May 20 '13 at 14:48

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