Soil pipe repair

[Lobster]

Got a bit of a problem with a leaking soil pipe and would appreciate some advice...

I have a boxed-in, steel (not cast iron) soil pipe, which feeds into what I assume to be the top of a clay drain pipe at ground level (ie, inside the house). Sort of like this...

steel soil pipe | | | | | | | |

-----|__|_ _|__|------------ground level | | | | | | | | | | clay drain

The gap/interface between the steel and clay pipes had been plugged and sealed with mortar, but this had cracked (radially), and there's been quite a bit of slow leakage within the boxing over time (fair bit of wet rot).

I've tried to gently chip out the mortar 'interface' in order to reseal it with new mortar, but not unsurprisingly have managed to bust the clay pipe. That is itself embedded in concrete - see

for a photo of the current situation! (there's also a new crack now, just visible at the 3 o'clock position).

At this point I really don't know what the hell to do. Digging out the broken clay pipe - which is embedded in the solid floor and then presumably turns to pass through the foundations - looks a non starter, and the only thing I can think of is just to lather the whole broken joint in oodles of wet mortar and hope for the best. Is that likely to work, though? It would make matters a lot worse if it doesn't! If that's the only way, any top tips to ensure a waterproof seal?

[Mike]

Is the pipe broken below floor level ? If not try to cut it off with and angle grinder to restore a clean edge and then go off to your local specialist plumbing merchants and they will sell you a 'precision fit' (i.e. hammer job) fixing which slides inside and provides a new fresh standard ring connector on the other end. Of course this will be for PVC pipe so you'll then need to convert this to the steel pipe which hopefully they can also provide.

[fred]

In article , Mike writes

Sorta like 12710/12716 here:

(near the bottom) but sized for your steel pipe, sure your merchant will find something if you go armed with the right measurements. Mentioning you want something like a WC pan adaptor but different might save on the explanations.

[Lobster]

Ah, right - I've used these before in a horizontal situation but for some reason it hadn't occurred to me they'd work vertically too! Having said that, I'm not entirely sure what interface I have with the clay pipe... if you look at my photo, the steel pipe is sitting on a horizontal, flat section of the clay pipe, and *that* is level with the floor - ie, presumably the internal bore of the clay pipe must be less than the external diameter of the steel pipe. Or is there likely to be some form of internal rim on the clay pipe, which the steel pipe's sitting on? Can't really see what's going on, and I'm not familiar with the geometry of the 'socket' on a clay pipe. Don't want to cut it all off flush with the floor unless it will definitely work, obviously!

[Chris Bacon]

It's difficult to get cement out of the socket, as you've found. The bedt way is very gently with a gentle hammer drill and a small bit, making lots and lots of holes, and drilling at an angle. However.

You need to get the metal pipe out of the way, & push in an adaptor which you can get from a BM or PM. It's a plastic version of the clay one, with rubber fins which seal between the clay & plastic. Break off the rest of the socket as cleanly as you can, then push the adaptor in. Re-position the metal pipe. Fill the socket with cement as normal.

[fred]

I think the steel pipe will just be sitting there, no socket other than the part that has broken and just the mortar will have been holding it in place. Now that it is broken I don't think you can rely on it sealing properly again so a rubber sealed adaptor socket is the way to go. I think your confidence will be raised if you go to your PM to have a chat and see what they have. Locally I have a drainage specialist who doesn't stock regular plumbing stuff at all and it is there that I would go if I was in your spot, perhaps you have a similar outfit in your area. Ideal would be to remove the steel pipe to check socket & pipe dims but I can understand you not wanting to do that until you get the necessary bits. Get the to the PM :-)

Btw, the fact that it has leaked at all (if the socket wasn't broken before) suggest that the soil pipe may be backing up a bit, just thought I'd mention it.

[Lobster]

Thanks Fred - yes I'm sure you're right about the mortar being the only seal. I didn't mention it before, but in fact if you look at the photo

at the very back of the area now exposed by the lump having broken away, there is a cavity beneath the mortar seal, which AFAICS goes right round the pipe. There was the rotting remnants of some sort of fibrous material inside there, which I suspect may have been some form of spacer or washer? Make any sense? Also, if you look at the base of the lump which has broken away (now positioned upside down) you can just see annular grooves, with a corresponding pattern on the opposing face in the pipe. I'm wondering whether this lump has not broken off the pipe per se, but off a separate annular component? Might make a difference as to whether the Kwickfit adapter will work?

Anyway - having reinspected the 'project' this morning, I find that there is certainly no easy way to raise or move the steel pipe; it goes upwards through the ceiling (mating with the loo upstairs) and then continues straight up through the roof to a vent cowl. It's all very rigidly fixed and sealed in place and would be a nightmare to shift it. So I'm thinking, cut through the pipe about 1m above the floor so I can move out the bottom section. How would I successfully rejoin the cut ends - another Kwickfit adapter, assuming there's a suitable one available?

Oh, deep joy...

[Set Square]

Maybe the way to go is to use a 12716 pushed into the socket, and to shorten the steel pipe so that it just buts up to it. You can then use a

to join the steel pipe to the top of the 12716.

[fred]

In article , Set Square writes

Yep thought that might be the way to go and as were already placing an order to BES we can use theirs

, about half way down.

Right dave get on with it then ;-)

[fred]

In article , Lobster writes

I think we've got it sussed, have a look at my reply to Set Square, now get your rubber gloves on ;-)

[Lobster]

Thanks again! Yes I suppose I'd better, hadn't I! I won't be able do so now until early next week (don't worry, soil pipe is now out of service!) so stand by for panicked cries for help after I've cut the pipe and it turns out that all assumptions made were wrong.... ;-)

[Rob Morley]

I'd remove the remaining mortar and cut the pipe down flush, clean everything very throughly, apply a large fillet of silicone sealant then build up a ring of mortar so it looks like it did in the first place.

[Ian_m]

I am sure once when I fiddled around with a cemented soil pipe joint, the cast iron pipe (in my case) went into the vitreous pipe and the bottom of the joint was filled with something like "rope soaked in plumbers mait", with cement ontop. In my case the iron pipe was replaced with plastic and a rubber seal into the vitreous pipe.

[David Lang]

Rob Morley wrote;

My thoughts exactly. I had a similar leak on a cast iron soil pipe. Just built a box around it as formwork & filled it with fine concrete. That was

10 years ago and it's still K.

Dave