We are having a power flush today.

[classic33]

I'm unblocked!
Scottish Water man could not find the "stack" i.e. the sewer.
Private drain contractor found it: it was where I told Scottish Water man to check!
Cost me over 100 pounds, but on the bright side I know now all the drain pipes of the building, could even unblock the main sewer myself, like @Globalti suggested upthread.
Not that I would, mind, but I could
If I'm lucky, I'll get some money back from the upstairs owners, this should be a shared repair.
I'm just happy it is solved.

Block it above yours, say it's the same thing and get the money from them before "getting someone in" to clear it again.

 

[Lozz360]

I'd be surprised, normally it's your problem until it hits the shared sewer, our comes out the back of the house, under the garage & meets the main sewer in the road, anything before the footpath is our responsibility on Severn Trent

But as soon as the waste pipe is shared, it is the responsibility of the water co. even if the fault is on your land. The rules changed in 2011 I believe. Before then a fault on a waste pipe on your land would be yours to put right even if your neighbour’s waste joined it upstream. Last year the waste pipe underneath my drive collapsed and because my next door neighbour’s soil pipe joined mine before the collapse, Thames Water excavated my drive, replaced the pipe and made good the drive all at their expense.

 

[User6179]

But as soon as the waste pipe is shared, it is the responsibility of the water co. even if the fault is on your land. The rules changed in 2011 I believe. Before then a fault on a waste pipe on your land would be yours to put right even if your neighbour’s waste joined it upstream. Last year the waste pipe underneath my drive collapsed and because my next door neighbour’s soil pipe joined mine before the collapse, Thames Water excavated my drive, replaced the pipe and made good the drive all at their expense.

Are you not mixing up waste pipe( above ground) and sewer pipe(below ground)

 

[Globalti]

*disgusting story alert*

I'll tell you a story about this: my parents used to live in a cottage that had a septic tank. One day the downstairs bog began to back up so I went out and lifted the manhole cover between the bog and the tank and sure enough, it was full to the brim. No worries, we called a local farmer who came along with a huge cylinder that builds up a massive vacuum then sucks everything up a pipe, emptying the tank in one spectacular gasp.

However the pipe between the manhole and the tank was still blocked so I dressed in full waterproofs and put the drain rod down to clear it. Nothing much happened so I deployed the big rubber disc and gave it a really hard push. Anybody familiar with the physics of hydraulic pumps will understand what happened next; the dog suddenly went bonkers and began barking and leaping around and there we saw a square of gravel the shape of a manhole cover, under the drive halfway between the manhole and the tank, lifting slowly into the air while geysers of unmentionable stuff sprayed out all around. You can imagine the hilarity!

So I uncovered and lifted the downstream cover and redeployed the big plunger and pushed hard and slowly the disgusting blockage began to emerge like a fat sausage, splattering into the tank, causing even more hilarity and the dog to almost wet herself with excitement. After that it was a simple matter of washing myself, the equipment and the area around with the hose and heading indoors for a well-earned cuppa.

 

[Lozz360]

Are you not mixing up waste pipe( above ground) and sewer pipe(below ground)

OK I was referring to below ground drainage as waste pipe. Some would refer to all below ground waste as a sewer. I would only refer to the sewer as the channel that runs underground along the road and all that is downstream of that. Anyway, I’ll explain with the aid of the diagram below. As you can see, if you live in a house, the waste or sewer that is yours and yours only, is your responsibility to fix (yellow pipe). As soon as you share with a neighbour (red pipe) it is the water company’s responsibility even if the problem is on your land. A block of flats is different as the responsibility is shared amongst the owners (purple pipe). My first post in this thread was not correct. Sorry, @Pat "5mph" as I thought that flats would be the same as houses regarding the point that waste pipes are shared.

 

[classic33]

*disgusting story alert*

I'll tell you a story about this: my parents used to live in a cottage that had a septic tank. One day the downstairs bog began to back up so I went out and lifted the manhole cover between the bog and the tank and sure enough, it was full to the brim. No worries, we called a local farmer who came along with a huge cylinder that builds up a massive vacuum then sucks everything up a pipe, emptying the tank in one spectacular gasp.

However the pipe between the manhole and the tank was still blocked so I dressed in full waterproofs and put the drain rod down to clear it. Nothing much happened so I deployed the big rubber disc and gave it a really hard push. Anybody familiar with the physics of hydraulic pumps will understand what happened next; the dog suddenly went bonkers and began barking and leaping around and there we saw a square of gravel the shape of a manhole cover, under the drive halfway between the manhole and the tank, lifting slowly into the air while geysers of unmentionable stuff sprayed out all around. You can imagine the hilarity!

So I uncovered and lifted the downstream cover and redeployed the big plunger and pushed hard and slowly the disgusting blockage began to emerge like a fat sausage, splattering into the tank, causing even more hilarity and the dog to almost wet herself with excitement. After that it was a simple matter of washing myself, the equipment and the area around with the hose and heading indoors for a well-earned cuppa.

How'd you wash what you were wearing?

 

[Globalti]

Get somebody to spray you with a hose?

 

[pawl]

I find Senokot very good.

 

[Pat "5mph"]

@Lozz360 cheers, but Scottish Water man said my pipe responsibility ends at the common entrance.
In the event, he could not find any obstructed pipe, so he told me to call a private contractor because it must have been an inside obstruction.
Scottish Water man (well, young man, actually) was wrong: the pipe was indeed obstructed on his domain, the private contractor found it (he was more experienced) and cleared it.
All is well that ends well

 

[fossyant]

*disgusting story alert*

I'll tell you a story about this: my parents used to live in a cottage that had a septic tank. One day the downstairs bog began to back up so I went out and lifted the manhole cover between the bog and the tank and sure enough, it was full to the brim. No worries, we called a local farmer who came along with a huge cylinder that builds up a massive vacuum then sucks everything up a pipe, emptying the tank in one spectacular gasp.

However the pipe between the manhole and the tank was still blocked so I dressed in full waterproofs and put the drain rod down to clear it. Nothing much happened so I deployed the big rubber disc and gave it a really hard push. Anybody familiar with the physics of hydraulic pumps will understand what happened next; the dog suddenly went bonkers and began barking and leaping around and there we saw a square of gravel the shape of a manhole cover, under the drive halfway between the manhole and the tank, lifting slowly into the air while geysers of unmentionable stuff sprayed out all around. You can imagine the hilarity!

So I uncovered and lifted the downstream cover and redeployed the big plunger and pushed hard and slowly the disgusting blockage began to emerge like a fat sausage, splattering into the tank, causing even more hilarity and the dog to almost wet herself with excitement. After that it was a simple matter of washing myself, the equipment and the area around with the hose and heading indoors for a well-earned cuppa.

Thanks - you can keep that to your memories.