Leaking toilet soil pipe when going into internal wall :(

[zander's dad]

Even turning the water off to the toilet in the bathroom shouldn't stop that cold water supply pipe from leaking, if that's where it's coming from, as that would still be under pressure unless the mains was turned off.

The flexible pipe you are turning off, does that connect up into the bottom of the toilet cistern and then the leak stops? As suggested, that lower gray supply pipe does look damaged. The black soil pipe section on the left is a blank boss so it shouldn't be leaking there, unless it's been cored at some point and then blanked off and that's what's leaking.

The OSB3 to the left of that boss connector is that a webbed I joist? If so you may need to open that section up from above unfortunately.

Correct- when the flexible pipe is turned off, it does connect to the bottom of the toilet cistern, and, yes, the leak stops. Noted re the gray supply pipe, have checked for any signs of water and there's nothing leaking. Re the blank boss- I can prise the pipe away a good couple of mm from the OSB3, and then get a few drips at the bottom of the pipe.

 

[zander's dad]

Even turning the water off to the toilet in the bathroom shouldn't stop that cold water supply pipe from leaking, if that's where it's coming from, as that would still be under pressure unless the mains was turned off.

The flexible pipe you are turning off, does that connect up into the bottom of the toilet cistern and then the leak stops? As suggested, that lower gray supply pipe does look damaged. The black soil pipe section on the left is a blank boss so it shouldn't be leaking there, unless it's been cored at some point and then blanked off and that's what's leaking.

The OSB3 to the left of that boss connector is that a webbed I joist? If so you may need to open that section up from above unfortunately.

Sorry double post

 

[zander's dad]

Even turning the water off to the toilet in the bathroom shouldn't stop that cold water supply pipe from leaking, if that's where it's coming from, as that would still be under pressure unless the mains was turned off.

The flexible pipe you are turning off, does that connect up into the bottom of the toilet cistern and then the leak stops? As suggested, that lower gray supply pipe does look damaged. The black soil pipe section on the left is a blank boss so it shouldn't be leaking there, unless it's been cored at some point and then blanked off and that's what's leaking.

The OSB3 to the left of that boss connector is that a webbed I joist? If so you may need to open that section up from above unfortunately.

Correct- flexi hose that connects when turned off stops the leaking. Gray supply checked a few times when water on and off, and no signs of any leaking. Thanks for your help! However I can also prise the pipe leading into the OSB by a couple of mm and that causes a couple of drops to form along the bottom of the pipe.

 

[Madrab]

Correct- flexi hose that connects when turned off stops the leaking

OK, there's a couple of things don't make sense - turning off that service valve connector connected to the toilet fill valve, wouldn't stop any leak in that grey pipe in the pic or in that location.

Why the water only manifests itself at that boss section of the stack is confusing as the only water that would be running there, if not from the grey supply pipes above it, would be waste water from the toilet. That could only occur if the flush valve was passing or the cistern was overflowing, down into the pan and then down into the soil pipe. Is there water running/trickling constantly into the pan?

If not then it's conundrum as that's the only things that it could be, so again and unfortunately, it would then time to open that section of the floor above up and physically see where the water was coming from. Given it looks like vinyl flooring, that may not be too much of a nightmare.

 

[zander's dad]

Think I've discovered the issue which was a complete "doh" moment. Put some food dye in the cistern and ever so slight leak into the toilet bowl. I've taken the flush valve out and reseated it and the leak has virtually stopped and there is a bit of pitting/ unevenness on the rubber seal at the bottom of the flush valve. I've kept the water supply on to the toilet and minimal leaking at the scene of the leak previously in the ceiling. Will get a new flush valve and hopefully that will be the end of it. Thanks to all for their responses and honours go to CBW for the flush valve fitting shout!

 

[HERTS P&D]

Yes, but where is the leak?

Andy

 

[Harry Bloomfield]

Will get a new flush valve and hopefully that will be the end of it. Thanks to all for their responses and honours go to CBW for the flush valve fitting shout!

That makes no sense - despite fixing the flush valve, you still have an unresolved leak on the pipe, which you had before, it will just be less persistent.

 

[zander's dad]

Just to update- the issue now appears to be the boss coupler on the soil pipe that's either cracked/ failed in some way. I mistakenly thought the side of the coupler which didn't have a pipe must've gone into a pipe internally. Clearly that wasn't right. So, it's a pig of a job which can't be done from downstairs. Only option appears to be take bathroom floor up, and do it that way. A right pain in the a*se but at least that will explain why the leak is occurring. Probably was knackered when installed originally by the cut-and-run ****es know as Wainhomes.

 

[zander's dad]

So, just as a follow-up is there a quicker way to fix. i.e .if the bit of the pipe facing the wall doesn't actually do anything, could that be cut back and "blanked" off robustly?? Just thinking out loud and how to avoid a shedload of disruption

 

[Madrab]

In a word no - it's unusual for that section to fail as it's moulded single piece unless, as I mentioned before, someone was playing about with it and maybe damaged it.

If that is directly beside the toilet though then it shouldn't be that difficult to fix from above - if the flooring is vinyl then that should lift quite easily and then it's just cutting a square section of the floor out, take out the pan connector cut the 40mm waste pipe and pull that boss connector out of the stack and replace it, then refit is the reverse with a bit of juggling for the 40mm waste, all relative straightforward.

A bit of upheaval yes but there are a lot more awkward repairs than that TBH.

 

[zander's dad]

In a word no - it's unusual for that section to fail as it's moulded single piece unless, as I mentioned before, someone was playing about with it and maybe damaged it.

If that is directly beside the toilet though then it shouldn't be that difficult to fix from above - if the flooring is vinyl then that should lift quite easily and then it's just cutting a square section of the floor out, take out the pan connector cut the 40mm waste pipe and pull that boss connector out of the stack and replace it, then refit is the reverse with a bit of juggling for the 40mm waste, all relative straightforward.

A bit of upheaval yes but there are a lot more awkward repairs than that TBH.

thanks Rob, v helpful

 

[Madrab]

Only thing I will mention is if you are attempting the repair then be careful when pulling that boss connector out - in case the stack lower down is into another pushfit section, you don't want to be pulling out the whole stack lower down so you will have to go 'Jonnie go lightly' with it. It's hard to explain as it's a feel thing as to what section light be moving, just keep a good eye on things as it's going.

 

[DP]

Thanks, three pics as follows- the first shows the feed pipe going up through the floor which is linked to the isolation vale in pic 3. Pic 2 shows the top grey pipe being the pipe which leads from the isolation valve to underneath the floor. Hope this helps.

Don’t care for this type of pan connector, nor the way the inlet to cistern run.

 

[DP]

Duplicated

 

[Nige F]

In a word no - it's unusual for that section to fail as it's moulded single piece unless, as I mentioned before, someone was playing about with it and maybe damaged it.

I wonder if the boss was drilled by mistake - maybe just the pilot hole ? Of course it's hidden by the web of the joist. Is it allowed to use a holesaw larger than the boss - from the other side of the web ( with a short pilot drill) so you can see what's happening ? Just an idea but what are the regs regarding holes through those webs ?