Soil pipe across neighbour land broken by them

[Carrerahill]

On 14/08/2021 at 19:54, ashthekid said:

The neighbours builder claims it doesn’t have the adequate gradient run from our manhole so it’s likely to block up and come back towards us. This is despite us having no issues whatsoever during the course of our conversion works with any blockages or backup. It all seems to drain away ok. 

He is a builder, not a civil engineer or drainage expert. Builders think water is easy. Say that to a water engineer. 

[Carrerahill]

On 14/08/2021 at 23:53, ashthekid said:

@Temp that is very interesting. I wonder if the neighbours are aware of that. 
I wonder if it matters that the pipe leaves our boundary and into the neighbours back patio before then passing underneath their property to the main road. 
That illustration shows it out front by the public pavement. 

I can say with absolute certainty, your neighbours are dealing with a sewer in their garden, not your soil pipe, a soil pipe is a private water waste line, a sewer is a public duct for water waste. 

 

The builder will know this too, he doesn't want the water board to know. I would call the water board.

Edited August 18, 2021 by Carrerahill

[Carrerahill]

On 15/08/2021 at 00:21, PeterW said:

Bigger concern is that your neighbour is digging over or near a lateral drain or sewer. If that is the case they need a build over agreement and your neighbour will need to do that at their cost not yours. Minimum will be repair and lintels, worst case is they need to move the drain or re-lay it. 

Indeed.

 

I suspect that is why the builder is trying to put the onus onto the OP. He knows this is an issue, perhaps didn't allow for it and thinks the OP can now be made to foot bill. Well I am sorry but this builder has been caught out or didn't do due diligence. 

 

Interestingly, this could now delay the neighbours build until this is all agreed and new warrant drawings approved.

 

Time to get real with them.

 

 

[Carrerahill]

1 hour ago, ashthekid said:

 

1) installing a pump at my end

2) rerouting all of our pipework directly to the street which would be a nightmare

3) reroute our waste to a tank in our back garden

 

 

1. Not a chance in hell - they need to deal with it on their side. 

2. As above.

3. As above.

 

They need to redo their drains and leave the manhole alone because that is serving your house, in fact, they have no right really touching said manhole as it is not theirs!

 

They must leave a system in place for your house.

 

 

[PeterW]

I refer to my previous point - I think they have not told BCO and WaterCo that there is sewage works as part of their extension. As such, the cost and issues are all theirs not yours. 

[epsilonGreedy]

29 minutes ago, Carrerahill said:

It is not your soil pipe as soon as it leaves your boundary, it becomes a sewer after this point and is the responsibility of the water board.

 

 

That is an interesting subtlety I was unaware of.  I thought the public sewer began at the most upstream connection point of private soil pipes, but your post and the @temp diagram indicate the public sewer starts at the upstream boundary of the plot where the connection is made.

 

I wonder what financial hit the bean counters at the big water co's calculated when the new 2011 legislation came into effect since they are now responsible for a much larger drainage network.

[saveasteading]

It is in your neighbour's interests as well as yours to get this sorted now.

As above, it is easiest to deal with before buried, and the building inspector is unlikely to be made aware of the issue.

 

If it is the LA inspector, I would speak to them first, just say you are concerned and ask if they considering your position.

otherwise, yes the water company.

 

On fitness for purpose. If it has worked for decades then it is fit for purpose. 

Being on a very flat gradient seems to be ok for you now, but if they meddle with it it might cause back-ups in your perfectly good pipe.

 

eg. you flush and it goes away.

you flush same time as them and it all swirls and slows, and solids sit down and stay put.  problem.

 

37 minutes ago, Carrerahill said:

Builders think water is easy. Say that to a water engineer. 

It amazes me how little is understood by builders, about water.  The less they know, the more they seem confident of their expertise. I think it is part of the 'too much of experts' mentality. Don't know enough to know how little they know.  Or he was bluffing/bullying.

The contrary by Einstein is “The more I learn, the more I realize how much I don't know.”  Most of us on this forum are with Herr Einstein.

Where is nextdoor's  groundworker?

 

[ashthekid]

@Temp The neighbours already have an existing manhole which he says has an almost equally bad run into their neighbours next to them. They aren’t installing any new pipework for themselves. It’s just my pipework that they are concerned about apparently. He said that the Water Company might insist on all of our runs to be dug up and repaired with a proper run that will pass building control recommendations for gradients. 
 

@dangti6 I don’t think there is anything in the deeds that specifically relates to these pipes or sewerage. I couldn’t see anything about it. And no sewerage plans upon purchase as it went into the neighbouring property and there were no obvious problems or issues with waste disappearing. 
 

@Carrerahill it’s not fit for purpose apparently because the gradient isn’t sufficient to give it a good enough run and according to the builder it won’t last once our conversion project is finished and my family is living there using multiple toilets/showers/sinks etc. The whole run from all three property’s that share the same pipe is probably inadequate according to Building Control despite it being fine for many years. That said, the neighbour has apparently experienced some issues with blockages from their property to the shared pipe but that’s not been on the section from my property of course. 

[PeterW]

38 minutes ago, ashthekid said:

The whole run from all three property’s that share the same pipe is probably inadequate according to Building Control despite it being fine for many years.

Who’s BCO..?? If it is from 3 properties then it is the Water Co problem to resolve. 

[ashthekid]

Update:

So it seems the neighbours builder has created a workaround - to create a totally new drain for them. Replace the existing pipework from ours, leaving us with access to the existing manhole inside their patio(that isn’t being built on). We will be the only ones using the existing drain and they will have access to a newly created drain which I’m assuming will be raised so they have the adequate run whilst we will continue to use the current run that has existed for years, albeit without the little raise that was there but not causing us a problem. 

They’ve asked me if I want to raise the inlet on our side of the boundary party wall then I must let them know by 4pm tomorrow. Sadly we can’t do that because of all the pipework we have already concreted into the groundworks with the correct runs etc. 

Seems a logical solution?!?

 

Do you think I still get Water Company involved at this stage?

[ashthekid]

@PeterW 

2 hours ago, PeterW said:

Who’s BCO..?? If it is from 3 properties then it is the Water Co problem to resolve. 

The neighbours BCO apparently.

[Temp]

2 hours ago, ashthekid said:

They aren’t installing any new pipework for themselves. It’s just my pipework that they are concerned about apparently. He said that the Water Company might insist on all of our runs to be dug up and repaired with a proper run that will pass building control recommendations for gradients. 

 

Normally the BCO won't look at existing drains unless alterations or new connections are being made. I'm wondering if the BCO knows they should have got approval from the water co and that's the real reason for his concern.

 

2 hours ago, ashthekid said:

He said that the Water Company might insist on all of our runs to be dug up and repaired with a proper run that will pass building control recommendations for gradients. 

 

I think its unlikely given there haven't been any problems with it and nobody is making any changes to it.

 

If the neighbours are building over the sewer then they should be getting approval from the water co. The water co might insist the sewer is diverted around their foundations or allow them to build over. In some cases it is not possible to do what water co insist on. In such circumstances it might not be possible to build what/where they want.

 

 

 

[Temp]

15 minutes ago, ashthekid said:

So it seems the neighbours builder has created a workaround - to create a totally new drain for them. Replace the existing pipework from ours, leaving us with access to the existing manhole inside their patio(that isn’t being built on). We will be the only ones using the existing drain and they will have access to a newly created drain which I’m assuming will be raised so they have the adequate run whilst we will continue to use the current run that has existed for years, albeit without the little raise that was there but not causing us a problem. 

 

Get photos of the existing layout and the new one.

 

If the new pipe is no longer shared then it might become your responsibility rather than the water co. If you have photos you can prove it was theirs and the neighbours changed it.

 

 

 

[epsilonGreedy]

4 hours ago, Temp said:

Get photos of the existing layout and the new one.

 

If the new pipe is no longer shared then it might become your responsibility rather than the water co. If you have photos you can prove it was theirs and the neighbours changed it.

 

 

This would be my concern because the neighbour's new drainage scheme might disinherit the OP from the rights gained in the 2011 change of legislation. However would any 3rd party be motivated to intercede on behalf of @ashthekid?

[saveasteading]

As long as they repair your pipe properly, and it would be appropriate for them to get the building inspector to check it, then all should be ok.

1. I have seen clay pipes linked by a different size of plastic pipe, with no collars and only using silicone mastic.

2. it seems they are still trying to worry you, or they are ignorant of how drains work. Your pipe should stil be fin with more appliances.

Your pipe will again have a nice clean run, and it has worked well in the past.

It is always, and correctly,  assumed in the regulations that you won't all flush at the same time, to deliberately overload the system. 

3. the flow tables in the building regulations are a little conservative. There are much more complex means of calculating flow, and it seems likely, based on reality,  that your pipes would pass. 

 

I suggest you photograph the pipe now and after repair, and insist that an expert inspects it.

[ashthekid]

I spoke to the Water Company and they have confirmed it’s their responsibility but the neighbour has been told it isn’t which is rather frustrating. 
If it doesn’t belong to the Water Company what does that mean for the pipe?

And I assume a Build Over Agreement is no longer needed?

[Faz]

I think that once the drain has been adopted it stays adopted even if the usage changes.  How large is the pipe?

 

The minimum fall on a 110mm pipe is 1 in 12. This goes to 1 in 24 for a 160mm pipe.

[epsilonGreedy]

22 minutes ago, Faz said:

The minimum fall on a 110mm pipe is 1 in 12. This goes to 1 in 24 for a 160mm pipe.

 

 

I think it is 1 in 80 or 12.5mm per meter.

 

My wise old building adviser who has worked for 40 years in the gradient challenged East Anglia told me that 1 in 100 works.

[Faz]

You're right - 1 in 0.0125 ie 1 in 80. I was getting my measured fall confused into a ratio - thanks for correcting!

[Marvin]

1 hour ago, Faz said:

You're right - 1 in 0.0125 ie 1 in 80. I was getting my measured fall confused into a ratio - thanks for correcting!

Thought it depended also on the diameter of the pipe...

Edited August 19, 2021 by Marvin

[epsilonGreedy]

2 hours ago, Faz said:

You're right - 1 in 0.0125 ie 1 in 80. I was getting my measured fall confused into a ratio - thanks for correcting!

 

 

There is another useful gradient unit of scale that the wise old builder taught me.

 

If a soil pipe is laid correctly at 1 in 80 then when a 1.2m long spirit level is placed along the top of the soil pipe and the down hill end is raised with a man's index under that end, the level bubble should be at the center.

[saveasteading]

Page 15 on this gives standard flows and gradients. as you say, 1:80.

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/442889/BR_PDF_AD_H_2015.pdf

 

I did unfortunately once employ a  groundworker subby who's digger man  ignored our designed gradients and put it in much steeper.. He knew better than us apparently. Expensive.

 

Just saying as perhaps there is a wrong rule of thumb out there, among drain installers who need it steeper to overcome workmanship problems.

 

[joe90]

1 hour ago, epsilonGreedy said:

If a soil pipe is laid correctly at 1 in 80 then when a 1.2m long spirit level is placed along the top of the soil pipe and the down hill end is raised with a man's index under that end, the level bubble should be at the center.

 

56 minutes ago, saveasteading said:

Just saying as perhaps there is a wrong rule of thumb out there,

so, it’s a rule of finger, not rule of thumb ?????

[ashthekid]

If the pipework in question is considered a “private drain” by the neighbour with what they have been told, then who’s responsibility is it?

And if anything goes wrong with it over time?

[DragsterDriver]

Take pictures of all the existing and all their modifications. Ask building control to confirm they’re happy with it all.

 

the neighbours were definitely trying to bounce you into something.