Broken vertical clay pipe

[Bobbywiz96]

Hello, long time lurker/first time poster here.

Basically I've had to remove (and will hopefully replace..) the cast iron soil pipe on our early 60s semi. The old one came down without too much trouble but before starting I noticed the collar on the clay pipe was cracked. Sadly the crack turned out to be a large broken piece going down in to the pipe. Seen here on the right;

20210805_121859

• Bobbywiz96
• 8 Aug 2021

I excavated a bit and am unsure how best to proceed. My current thinking is to make a bit of space, cut the pipe just below the break and then use one of those flexible adapters to join on the new 110mm plastic pipe. Not sure if that's the correct thing to do..? And if so how would I finishit off? Pea gravel around the pipe and lean mortar to top it off perhaps? Also, the clay pipe appears to have a bit of play in it. Not loads, but it surprised me as I thought it would be very rigid.

A couple more pictures with it cleared out a bit;

20210805_133715

• Bobbywiz96
• 8 Aug 2021

20210805_133705

• Bobbywiz96
• 8 Aug 2021

20210805_133712

• Bobbywiz96
• 8 Aug 2021

Any advice would be great!!

Thanks

 

[CBW]

It doesn’t appear to be cracked down the length, so either a dc1-bl and sand/cement flaunching, or if possible, angle grind to below the collar, and use same fitting, or a flexseal.

 

[Bobbywiz96]

Thanks CBW, that's really helpful. Do you have any thoughts on the clay pipe moving around a bit? I reckon I can probably move it around 10mm in any direction at the very top of it. Should I excavate a bit further down and replace the material surrounding the pipe with anything more appropriate? It appears to be just soil/clay/debris at the moment..

Thanks

 

[JohnD]

I reckon I can probably move it around 10mm in any direction at the very top of it

then it's probably got another break that you haven't found seen yet.

this is quite normal for old clay pipes.

You'll find it when you dig deeper.

 

[CBW]

It may have another break in it a second John suggests, however, don’t forget you’ve exposed quite a bit of drain, which might be why there’s movement.

 

[HERTS P&D]

You've got that far, keep digging and dig it out and replace the bend.

Andy

 

[Bobbywiz96]

Thanks for the replies guys. I think that it's probably about another 350/400mm before I get to the bend. Is it a particularly involved procedure to replace? Not too much more to dig I suppose, though more of the tarmac driveway will have to get smashed up.

I'm sort of on this 'may as well do it properly' journey at the moment, but because of it everything is taking ages haha. Best to do it well though, especially with the pipes in question..

 

[Hugh Jaleak]

Problem can often be with these old clay drains, where do you stop. I'd suggest you dig carefully, dont lever the spade to put any pressure onto the pipework, and see what sort of condition it is in further down, although it may not be a bad idea to replace the bend and at least ensure it's leak tight to a point the pipe is away from the wall of the house slightly. It would probably be very easy to condemn the entire run though, hence being gentle!

 

[Bobbywiz96]

Right, so I had a chance to do a bit more with this today. As you've all suggested I dug down a bit further and the pipe began to wiggle a bit a bit more and I could see the joint on to the bend. I was very gentle clearing it all out (mostly just scraped away with a pointing trowel tbh) but sadly the collar on the bend was in a load of bits.

Not sure how long it had been like that, the cracks were quite grubby and there was what appeared to be asphalt mixed in with the clay/gravel/soil so could've been whenever the previous owners had the driveway done.. who knows.

I'm thinking that replacing the bend is definitely the way to go, can anyone suggest what I need to buy? I've lifted the man hole for the sewer and the entry appears to be at 45 degrees from the current soil stack position. Am I to assume (foolish perhaps..) that the bend goes to a straight piece, then has a swept piece the connects to the sewer? So my new bend should *hopefully* just connect on to that straight piece?

I feel like the chasing back of this more and more broken clay pipe is like some sort of metaphor for the work we've been doing on the whole house haha.

Thanks for your help thus far!

Cheers,

 

[JohnD]

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