Leaking donut connection to cast iron hub

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Jen24

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I have a leak at the connection of were this sewer PVC pipe connects via a rubber connector to a lead (?) pipe the goes into my concrete garage floor. What can I use and how can I seal this myself. I was hoping to use a product without taking this apart and redoing it since I am not versed in this kind of work. Thank in advance for any input. See photos attached.

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Reach4

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Consider getting that pipe going into the floor rodded out.

It may be that you could drive that rubber donut in better, but if there is not water backing up, you you probably would not have pressure driving water around that donut.

fernco-donut.jpg
 

Jen24

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Consider getting that pipe going into the floor rodded out.

It may be that you could drive that rubber donut in better, but if there is not water backing up, you you probably would not have pressure driving water around that donut.
 

Jen24

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Thanks I think I need to get that rodding done. This is a 1978 house that has never been maintained well. This area was just painted over when I bought the house.
 

Jadnashua

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It's likely that the rubber donut is not sized properly unless the pipe is split. While the PVC going into it is a standard diameter, the ID of the hub is not which is why the manufacturer makes numerous donuts. Just like with Goldilocks and her porridge, you need one just right to make the seal.

Or, it's possible that whomever installed it, did not clean out the hub well prior to putting it all together.

So, maybe the easiest thing to do would be to cut the pvc where it's straight and long enough to install a banded coupler, pull the piece out of the hub, then clean it up, measure carefully, and get a donut the proper size, place the cut pieces back together and use the banded coupler to rejoin them, torque the screws down properly, and you're done. If you have the parts on hand, it's probably all of a 15-minute job. Clean up any burrs from cutting the pipe before putting it back together.
 

Jen24

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Thanks! When you refer to a possible split pipe do you mean the PVC pipe? Or the lead pipe that goes into the concrete? I think you are referring to the PVC pipe. It leaking water from just above the rubber donut. This only leaks when the 2 collection areas the kitchen sink faucet and the dishwasher are used. I believe that I use more water from both of these more than anyone that has lived here before. Also a lot of hot water since I replaced my tank hot water heater with a tankless. I did notice cleaning up right above the donuts lip maybe someone had tried to chalk it and painted over the whole thing. I kinda don't want to have the lead pipe cleaned out since it is under my concrete floor and am worried about a plumber damaging it and having to have the whole floor torn out to replace it.
 

Jadnashua

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The PVC pipe is going into cast iron, not lead (check it with a magnet!). NOw, originally, when it was CI to CI, they did use lead and oakum to make the connection, but when you use a donut like that, you need to clean the hub out of all of the lead and oakum, otherwise, the donut won't seal well to the hub. While yes, either the PVC or the CI could be split, if they are both intact, it's probably that they used the wrong sized donut.

So, maybe the first thing would be to verify that it's leaking at the donut, and not at a joint higher up, and just pooling at the hub. That can happen if they did not prime and cement the joints properly, or the pipe split.

You drain pipes should not leak during a backup, unless there's a defect somewhere. They should hold the waste even if filled entirely up to the first exit point (well, inlet from say a trap).
 
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wwhitney

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So, maybe the easiest thing to do would be to cut the pvc where it's straight and long enough to install a banded coupler
There's already one there, you can see it in the second photo, it's just been painted over.

Cheers, Wayne
 

Jen24

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There's already one there, you can see it in the second photo, it's just been painted over.

Cheers, Wayne
Where the pvc goes into the donut is where the leak is there is a gap there. Wayne ideas on how to fix this?
 

Jen24

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The PVC pipe is going into cast iron, not lead (check it with a magnet!). NOw, originally, when it was CI to CI, they did use lead and oakum to make the connection, but when you use a donut like that, you need to clean the hub out of all of the lead and oakum, otherwise, the donut won't seal well to the hub. While yes, either the PVC or the CI could be split, if they are both intact, it's probably that they used the wrong sized donut.

So, maybe the first thing would be to verify that it's leaking at the donut, and not at a joint higher up, and just pooling at the hub. That can happen if they did not prime and cement the joints properly, or the pipe split.

You drain pipes should not leak during a backup, unless there's a defect somewhere. They should hold the waste even if filled entirely up to the first exit point (well, inlet from say a trap).
 

Jen24

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Thanks, the leak is at the point where the pvc goes into the donut not above. There is a gap where the the pvc enters the donut. I have not checked the donut on the backside to see if it's cracked on that side. I don't know if there is supposed to be a gap where the pvc enters the donut. I think it should fit tight. Thoughts on this if you have time.
 

wwhitney

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There's already one there, you can see it in the second photo, it's just been painted over.
Maybe I'm wrong about that being a banded coupling, it's hard to tell with the paint. I would have expected a solvent weld coupling not to have protrusions like that, though.

As to fixing the leak, jadnashua's suggestion ("maybe the easiest thing to do . . .") is sound.

Cheers, Wayne
 
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Jen24

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Maybe I'm wrong about that being a banded coupling, it's hard to tell with the paint. I would have expected a solvent weld coupling not to have protrusion like that, though.

As to fixing the leak, jadnashua's suggestion ("maybe the easiest thing to do . . .") is sound.

Cheers, Wayne
 
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