Soil pipe keeps leaking

[JT101]

Hi guys

I have a soil pipe that won't stop leaking

In the original photo you can see there were 2 cracks in the cast iron pipe. When the drain got blocked, the water nearly backed out out the 1st floor toilet, and leaked through these cracks. Previous person put an ill fitting flexible coupler on the pipe.

We called out a local company who charged us £150 to try plunging the toilet (which obviously we'd done ourselves), and gave us a quote for £1500 to bring in some serious machinery to unblock the drains underground.

Rather than pay that, we cut out the damaged section of pipe. If you look at my diagram, you'll see you can't rod it around the elbow, nor from the manhole which slopes in the opposite direction.

So with some OneShot, and rodding the small section we could, eventually it seemed to release.

I replaced the pipe with plastic, socket at the top, and a securely fitted flexible coupler below.

Checked the toilet, and it flushed fine

4 weeks later, same problem, and it's also leaking out of that flexible coupler now!

So the questions are:

1) What else can I use on that lower joint to stop it leaking? I definitely tightened up the jubilee straps on there. I can't see how a slip coupler would be any better, especially since the cast iron and plastic are slightly different diameters

2) Is there any powerful equipment I could hire to blast out the drain, given the awkward arrangement underground which is all buried under concrete?
I do have access to a Karcher K5, but obviously the gun won't fit far down there. Are there any attachments I could buy? Not sure it will be powerful enough. I could borrow a friends Nilfisk

Thanks

 

[Hugh Jaleak]

I'd put money on the issue being at the bottom of the stack, either the rest bend at the bottom of the stack, or not far from that, the underground clay pipework has collapsed.

Jetting it with a pressure washer attachment may buy you some time, but really I would advise it needs proper investigation. May be able to get a smaller CCTV camera in from the top, down the stack and have a look what's going on at the bottom/under the concrete, but be prepared that you might have to start digging.....

 

[blup]

Its backing up as said.