Leaking Soil Pipe

Hi,

I've got a 4" cast iron soil pipe that passes through my laid-up stone foundation right where my chimney/fireplace base is located. There is an ash cleanout below the fireplace, and if you can believe it, the pipe passes right through this open space. As you stand in the basement, you can look into the ash cleanout, look up, and see the pipe passing through. And it passes through at about a 45 degree angle from right to left.

I'll follow this up with some photos later today.

A crack and leak has developed in this area. It took a long time to diagnose, because normal use does not cause enough leaking. But do a few loads of laundry and drain our new bathtub, and suddenly there's water on the floor.

A year or so ago, the soil line got blocked. A local rooter type company came out and blew the blockage down the line and then scoped it. The pipe extends straight out into the yard about 30 feet to and old stone drywell. (The house was built around 1830). There was a belly in the pipe about halfway out, but we didn't notice anything in the first couple feet of pipe.

Immediately inside the foundation wall was a tee that had cracked on the topside. A chunk of cast iron had fallen in, and this combined w/ the belly in the soil pipe probably contributed to the blockage. I replaced the tee w/ 4" PVC wye and a cleanout.

If I remove this tee, I know it's a straight line out of the house. I'm wondering if a length of 3" PVC will fit inside the 4" soil pipe. If so, I could pass enough of it down the pipe to clear the leaking section, and hopefully seal everything up inside the foundation at the bell of the soil pipe. Then reconnect to the PVC already inside the house. I'll have to rework the transition from the 4" to 3" to make sure I don't cause problems.

Any chance this would work?

I'm concerned about starting a proper soil pipe replacement job in the winter here in upstate NY, and the fact that it passes through the chimney base worries me too.

Thanks for any advice.

Tim

You do not want to transition from 4" to 3" as it will cause problems. You can only go from smaller to larger 3"-4" or 4"-5" ect. as you are heading to the street.

Also if the ash pit is active and the leaking water is passing through ashes the resulting liquid will be potassium hydroxide or potassium based lye. This can be very caustic and burn skin and eyes if contact is made. Flush with water if you get any on you.

Is there a possibility of cutting loose the cast iron and re-routing the sewer pipe with PVC thru the wall and re-connecting outside? Do away with all the old stuff that apparently is failing and needs replacing????

I'm sure I could dig outside the foundation and get that length of pipe out of there and replaced properly. I'm just concerned that it will be a real challenge given the wet winter conditions right now. If it were summer, I'd probably have it half excavated by now.

The ash pit isn't active, and at this point it looks like plenty of water has washed through there! But no doubt all that contributed to the corrosion of the pipe. Thanks for the words of caution though. I'll be wearing heavy rubber gloves, whatever I end up doing.

Most of the soil pipe inside the house has already been redone and is 3" PVC. If I replace the last few feet of 4" cast iron w/ 3" PVC, would it then make sense to try to insert the 3" PVC into the deteriorating 4" cast iron sewer line? I wouldn't have any 4" to 3" transitions.

Thanks again.

If the rest of the plumbing is 3" and only increases to 4" where it transitions to 4" Cast Iron, I cannot see why you could not slip some 3" PVC inside the 4" Cast using it as a sleeve...
We do it all the time when passing pipes through foundations etc...
We put pieces of Cast iron in the footings etc and then slip the PVC through it later....
I would only recommend this as a temporary fix till you can replace the whole line...
If I were in your shoes, I might be tempted to try to slip as much 3" into it as possible using couplings etc - the 3" couplings should slide through the 4" CI pipe.
Keep track of how much you put in then, come spring/summer, measure that far out in the yard and start digging...
Be sure to seal around the pvc pipe in the cast iron sleeve with some sort of waterproof sealant (hydraulic cement would work) We usually use waterproofing compound

If you can go from 3" to 3" which is inserted into the 4" it would be a handyman temporary repair until the weather got better....as long as you have plenty of slope so that the effluent doesn't wash back around the 3".

Thanks everyone. It seems to have worked. I was able to get about 7 feet of pipe out there. It fit tight and I had to hammer it along. I stopped once it really started to meet resistance. Anyway, I got it all rebuilt and have filled and flushed everything I can and no water is leaking in.

Whew!

Sweating feels good! Doesn't it????