Broken Sewer Line. Shifted about 1/2 inch down.

Looking for some advice.

I have 20 year old home that has a broken sewer line (steel) that cracked right at the foundation wall. The line shifted about 1/2” down and is resulting in a sewage smell in the basement.

The line is connected to PVC on the interior of the home and unfortunately the basement is finished limiting what I can do.

I spent a good portion of today digging up the pipe to hoping it wasn’t right at the wall but it definitely is. Any recommendations on how to fix properly?

 

Seems to me you will need chip away at the foundation to allow a portion of the PVC to be seen or enough that a sleeve can be attached to it. Then raise the iron pipe up using crushed stone to bring it level. Attach sleeve. Leave it open for at least 6 months to ensure it seals. If exposed to freezing conditions, throw insulation in the hole and maybe a small heater to be used during freezing conditions. If after 6 months or year, and no leaks, patch chipped area with new cement, bury it and plant grass.
Another possibility is to totally remove PVC pipe through the foundation and replace. But that will require inside work.

 

I have never seen a cast iron pipe break clean like that. Is it a break or is it a pipe connection that came apart?

I would go ahead and open up the wall inside the basement. Repairing sheetrock is easy and it will allow you to make a more proper repair. I don't like the idea of have a joint, fitting or connection right at the foundation wall. I would chip out the pipe in the foundation wall and run PVC through the wall and about a foot outside. Then I would install a cleanout to the surface with about 6" of PVC on the outlet side. Then use a boot coupling to connect to the cast iron. Code requires a no hub coupling with a metal shield on the outside but in this situation I prefer a plain Fernco style rubber boot for it's flexibility. Then patch around the pipe in the wall with mortar or hydraulic cement. Then coat the area with waterproofing. Backfill under the pipe and compact as best you can to support the pipe to prevent settling in the future. Then backfill and repair the wall in the basement.

This approach will get you new, good PVC through the wall without a joint or fitting in the wall for reliability and allow you to properly seal against water intrusion. The clean out, well... every house should have one and is a great saver if you ever have a clog. Then, the rubber boot coupling will allow some flexibility in case your sewer line settles or moves any more. If you leave about an inch or two gap between the ends of your old and new piping it will allow the rubber coupling to accommodate even more movement without damage/leaking.

 

I wouldn't try to fix a pipe in the wall like that. Too much work to get a potentially problematic connection.

I agree with Pilot Dane to open up the wall/floor and make the connections well outside and well inside the wall. Some locales require cast iron outside the house, check your local codes before replacing with PVC.

 

The soil under the cast ion pipe was never compacted before the pipe was covered way back when. I've seen this more with PVC pipe than with cast iron.

 

Thanks gents, I will be pushing a new PVC pipe through and connecting it to the cast iron pipe.

The cast iron pipe broke directly on the foundation wall, after breaking through the dry wall I could see the sleeve that was installed in the wall prior to the concrete being poured.

There seems to be two schools of thought on how to seal it up, some recommend hydraulic cement other urethane because of its expansion properties. Any thoughts? I was planning on using roof tar on the exterior wall after I seal this up as was done before.

 

I would let the size of gap determine what you use to seal around the pipe. For a large gap hydraulic cement would be better but if it's a pretty small gap then I'd use the caulk.

 

Just following up, when I started to chip away the exterior wall around the pipe, I actually found that they cemented over about 1.5" of the pipe before I was able to reach the wall sleeve. The gave me enough room to strap a clamp to it.

With this much material available, I ended up not having to cut out the pipe out of the wall sleeve:

• I cut back the cast iron pipe approximately 2 feet.
• Installed a PVC clean out.
• Clamped both ends of the PVC replacement to the cast iron pipes.
• Used hydraulic cement to seal up the foundation wall that I had to chip into.
• Waited one day for the hydraulic cement to fully cure, and tarred the exterior of the newly patched section of the wall.
• I then back filled with rock until 3/4" of the pipe was covered and made sure to tamp down the rocks to ensure real good coverage under the pipe.
• I think back filled the hole with the dirt I dug up and hopefully this holds forever as I do not want to dig that hole again!