Plumbing help please

[Jpwd3]

Hi,

in this current lockdown I would value some plumbing advice from the very knowledgeable people on here.

The only soil pipe in my house runs in a studwork box through the centre of the house. On Sunday whilst investigating something else I discovered that the soil pipe is leaking at the joint between the plastic and ceramic pipe. The ceramic pipe is firmly embedded in concrete and runs under the concrete floor. (See picture below).

It looks like it’s been weeping for some time, much of the box work was soaked and rotten. Having dried it all yesterday, out the leak is definitely coming through / around the cement sealing the plastic pipe.

Getting a plumber in is proving to be challenging. Is it possible / easy to make a repair myself (without making it worse)

Any advice would be appreciated.

many thanks
Paul

 

[addjunkie]

Ive used this for similar in the past

https://www.google.co.uk/search?cli...=mobile-gws-wiz-serp#lbl=OVERVIEW&pie=plaji-i


But if its free flowing down hill, it shouldnt leak back up the way. Is there a restriction somewhere

 

[steviec_lj]

Does sound like you probably have a blockage somewhere, which is holding the solids and liquid back, causing it to leak.

Is there anywhere you can fire a set of drain rods in to check?

Once you know it’s clear, you can repair the joint with cement, and when lockdown has passed get a camera up or down the pipe to check it hasn’t collapsed.

 

[Jpwd3]

Thanks, that’s helpful.

There is a manhole in the drive. I lifted it on Sunday and there is definitely flow when you flush the toilet, but I guess it could be partly blocked.

The access to the pipe is very tight - probably too tight for standard rods but I will buy one of these https://www.screwfix.com/p/drain-unblocker-7-6m/11325 and have a go.

There is also a rodding eye on the plastic soil pipe (you can just see it in the picture) I haven’t opened it yet for fear of it not sealing properly afterwards. In any case I think I'll try from the manhole first - before exposing the house to whatever might be blocked in the pipe!

 

[Agroshield]

But if its free flowing down hill, it shouldn't leak back up the way.

If the clay spigot is part of a bend, then water dropping in the stack can rebound and weep through the cracked or shrunken cement.

Dig out the cement. Do not crack the flange on the clay pipe. Fill the annulus half way with plumbers mait to give a flexible, watertight seal and then cap with 3:1 sharp sand/cement mixed with 50% PVA in the water.

 

[hunter27]

Good point about a partial blockage causing it to back up. Can you actually see where it is leaking out from? its not running down the pipe or dripping from higher up is it. If your not sure wrap some blue roll or similar around the pipe higher up and see if it gets wet and changes colour

 

[voipio]

Given that the damp joint is at floor level, there's a good chance there's a bend just below it. Water coming down the opposite side to the bend will tend to splash back a bit and, in any case, water flowing down the sides of the pipe will wick up the joint. Replacing the cement seal with new cement is probably the way to go.

 

[Jpwd3]

It’s definitely not running down the pipe from above. Overnight I sellotaped a piece of toilet roll around the pipe both at the level of the cement (which at that time was completely dry - at least on the surface) and at the joint between the two plastic pipes that's above it.

The morning the only dampness was on the piece around the cement - and even then only where it was touching the cement. The bit around the plastic joint was completely dry.

it sounds like we can,t completely discount a blockage / partial blockage - so rodding sounds like an initial option - followed by carefully digging out the cement (much of appears to be fairly soft), packing the gap with plumbers mate and then redoing the cement.

Access is not great but hopefully I can do that without cracking the ceramic pipe!!!

 

[Barking Mat]

Maybe it was a blockage, which has now cleared?

 

[Jpwd3]

I rodded the drain this afternoon, there didn't appear to be any blockage. The pipe isn't very far below the concrete flow as you could hear the metal spring of the unblocker as it was pushed along the pipe. The bend must be very shallow so it could easily be splash back and wicking.

I managed to some plumbers mate from Screwfix but finding any sharp sand was more of a challenge. Finally managed to get some this afternoon. The task for tomorrow is to carefully chip out the cement and re-pack with plumbers mate and then cement it all up again.

 

[Jpwd3]

So, cement chipped out - well lots of 4mm holes drilled mainly with a Dremel due to the poor access - and then gently chipped out.

Once out the pipe didn’t appear to have any seal / sealant apart from the cement. The lowest plastic pipe had a castellated flange that rested on the inside of the ceramic pipe and then the annulus had been filled with the cement I had removed.

Without the cement the only thing stoping the plastic pipe from moving within the ceramic pipe was the rigidity of rest of the soil stack.

Anyway, I packed the annulus with plumbers mate to 1/2 way - and then topped it with cement. Hopefully it won't now leak! I guess we'll find out!