# Repair of cast iron sewer pipe within concrete



## RegeSullivan (Dec 8, 2006)

I do not know of any DIY fixes for this but in my area some plumbing companies that specialize in sewers install epoxy liners. I have seen it done on a 16” public sewer line and it only took a few hours.

Rege


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## Grampa Bud (Apr 6, 2009)

Breaking through a radiant floor for anything is definitely not a happy thought. It would be the proper way to permanently fix the problem though . If you have a 2-3" hole in the side of the pipe 16" under the slab you should be right near the bend in the closet bend under your closet flange. You will probably find additional cracks radiating out from the hole as well so any type of sleeve repair is only going to be temporary. Most radiant jobs are held back 12-18" from the flange so heat won't melt the wax ring. You could carefully chop the concrete around the flange, by hand, back about 6-8" from the flange, dig down past the hole depth about 3-4", again by hand with a garden trowel, slit a 4" Fernco from end to end, wrap it around the cast iron closet bend, loosely put the screw clamps on it and slide the Fernco down over the hole with the slit opposite the hole and tighten the clamps (5/16 nut driver). Grab a gob of silicone in your bare hand and lather the slit in the rubber. Rebury the pipe to about 2-3" below the flange and fill in the remaining hole with a little concrete. If there is any more root intrusion at that location it should be in about 50-75 years. Just remember not to try to rod the drain from that location. You are gauranteed of finding and hooking the Fernco.


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## al's sewer (Apr 7, 2009)

see if there is a company in your area that does sewer lining. I don't know how far down your pipe goes but they might be able to just put in a short liner. where are you at.


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## cando (Apr 20, 2009)

*Cast iron pipe repair in concrete slab*



al's sewer said:


> see if there is a company in your area that does sewer lining. I don't know how far down your pipe goes but they might be able to just put in a short liner. where are you at.


 
Thanks for this. I live in San Rafael. I think I will clean out the hole in the side first. A drainage company told me a quick set epoxy filler would do the job. I think I wiil do a PVC sewer and drain pipe sleeve also,after I fit it inside the 4 " cast iron. I will epoxy this in as well and extend past the hole a few inches. I will rip a 4 in. PVC down 2 kerfs along a a 20 " pipe in order it will collapse enough to slide down the inside of the cast iron. I will glue this in place with a polyurethane adhesive.

Thanks


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## cando (Apr 20, 2009)

Grampa Bud said:


> Breaking through a radiant floor for anything is definitely not a happy thought. It would be the proper way to permanently fix the problem though . If you have a 2-3" hole in the side of the pipe 16" under the slab you should be right near the bend in the closet bend under your closet flange. You will probably find additional cracks radiating out from the hole as well so any type of sleeve repair is only going to be temporary. Most radiant jobs are held back 12-18" from the flange so heat won't melt the wax ring. You could carefully chop the concrete around the flange, by hand, back about 6-8" from the flange, dig down past the hole depth about 3-4", again by hand with a garden trowel, slit a 4" Fernco from end to end, wrap it around the cast iron closet bend, loosely put the screw clamps on it and slide the Fernco down over the hole with the slit opposite the hole and tighten the clamps (5/16 nut driver). Grab a gob of silicone in your bare hand and lather the slit in the rubber. Rebury the pipe to about 2-3" below the flange and fill in the remaining hole with a little concrete. If there is any more root intrusion at that location it should be in about 50-75 years. Just remember not to try to rod the drain from that location. You are gauranteed of finding and hooking the Fernco.


 
Thanks Grandpa.......I think I will avoid this hassle of digging. I think I will do a "leakmaster" quick setting epoxy. I may also slide in a 20 " sleeve of PVC sewer and drain pipe and epoxy that in as well. The thickness of the PVC is minimal and I will use a table saw to rip down the length 2 times in order the sleeve will conpress inside the cast iron. This will be glued in also with a great polyurethane adhesive.

Thanks for your time and advice!!!


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