waste pipe is running back towards house

[vagrantly3893]

Our toilet was draining very slowly and we discovered that part of the waste pipe is falling towards the property.  I'm going to adjust it so it is falling away, but how can I achieve this so the pipe doesn't fall back? The pipe is currently in soil 60 cm down. Should I simply put soil back under the pipe after adjusting, or perhaps something like gravel or sand to hopefully prevent any future sinking?

Edited August 4, 2023 by vagrantly3893

[Chanmenie]

It should have gravel under it, but you could also put concrete under it to stop it moving. 

[Crunchynut]

Lift the pipe to create a suitable fall then pour pea gravel in the ditch. The gravel will naturally fill beneath the pipe and prevent it falling back. Further fill over the pipe with gravel to about 150mm above the pipe then put back the top soil to ground level.

 

The gravel serves to allow some natural movement as the earth swells and dries through the seasons and also prevents sharp stones that may otherwise be in the back-fill damaging the pipe.

Edited August 5, 2023 by Crunchynut

[markc]

How did you discover the reverse fall? CCTV? Unless you have already done so check the available fall to next inspection point or manhole (should it be personhole now?)

[Conor]

You need to establish a consistent fall from the start of the pipe run, all the way to the next chamber. If it is just at a pipe joint, you might get away with excavating a couple metres either side, cutting the pipe and inserting a new section.

 

Other than that, there's no way to adjust a buried pipe unless you excavate the entire length. You can simply lift one end and fill underneath it.

[Temp]

15 hours ago, vagrantly3893 said:

Our toilet was draining very slowly and we discovered that part of the waste pipe is falling towards the property.  I'm going to adjust it so it is falling away, but how can I achieve this so the pipe doesn't fall back? The pipe is currently in soil 60 cm down. Should I simply put soil back under the pipe after adjusting, or perhaps something like gravel or sand to hopefully prevent any future sinking?

 

It should already be bedded on/in pea gravel.

 

I would lift that section and a further 100-150mm down. Compact any loose ground using something like a fence post to pound it down. Fill with gravel raked to give you the required fall. Fit pipe and pour more gravel to cover it.

 

https://www.pavingexpert.com/drain02

 

 

 

Quote

The pipe should be settled into the bedding or have the bedding packed beneath it until it is at the correct alignment and level as indicated by the guide line (string or laser).

 

[vagrantly3893]

6 hours ago, markc said:

How did you discover the reverse fall? CCTV? Unless you have already done so check the available fall to next inspection point or manhole (should it be personhole now?)

Got some pics now.

 

The red section has sagged and even has a dent on the top. No gravel under or around the pipe. The connection closest to the house was also loose.

 

Plumber will be back in Monday and will probably replace everything from the house to the start of the long section (the part with the small hole in the top).

[Conor]

You should put an inspection chamber at that bend and get rid of that vertical pipe, whatever it's doing there.

[vagrantly3893]

2 minutes ago, Conor said:

You should put an inspection chamber at that bend and get rid of that vertical pipe, whatever it's doing there.

I assumed that was an inspection chamber. I'm also not sure why it's there though.

[markc]

Agree with @Conor the whole section looks pretty poor so you mayas well do it right, I would also be replacing the next section as a minimum, guessing the hole is from a pick. 

[Conor]

It's a bodge. I'm not even sure that that grey pipe is underground rated, it's normally orange/brown. I'd take it all out.

[Nickfromwales]

1 hour ago, Conor said:

It's a bodge. I'm not even sure that that grey pipe is underground rated, it's normally orange/brown. I'd take it all out.

+1. 

[Temp]

+2

 

Most underground pipe is brown/orange and stronger, more rigid than the grey indoor pipe. Might explain the dent?

[vagrantly3893]

3 hours ago, markc said:

Agree with @Conor the whole section looks pretty poor so you mayas well do it right, I would also be replacing the next section as a minimum, guessing the hole is from a pick. 

The hole was from the plumber during investigation. That part of the pipe just happened to be exposed because we dug a trench for an electric cable recently. I dug up everything else today.

 

2 hours ago, Conor said:

It's a bodge. I'm not even sure that that grey pipe is underground rated, it's normally orange/brown. I'd take it all out.

 

8 minutes ago, Temp said:

+2

 

Most underground pipe is brown/orange and stronger, more rigid than the grey indoor pipe. Might explain the dent?

 

Wouldn't surprise me considering what the previous owner has done elsewhere.

 

Worth mentioning however that I am in Germany so grey pvc pipe for outdoor burial is common.

 

 

Edited August 5, 2023 by vagrantly3893

[Temp]

Not sure about german regs but a bit of googling found..

 

https://www.rehau.com/downloads/1273612/awadukt-sewer-pipe-system.pdf

 

Quote

The integral colouration of the pipes requested in DIN EN 1852 enables a clear identification as a waste water and rainwater sewer thanks to the colours orange and blue used.

 

[vagrantly3893]

Here is the plumber's solution

 

[TonyT]

He’s not a plumber, he’s a chancer

time to bin him and find some decent trades before this  buried and causes you no end of problems 

[Nickfromwales]

The transition from ‘old to new’ seems odd, which may have left a step inside the pipe. Hard for us to comment / judge tbh as these are German standards and fittings not UK. 

[vagrantly3893]

1 minute ago, Nickfromwales said:

The transition from ‘old to new’ seems odd, which may have left a step inside the pipe. Hard for us to comment / judge tbh as these are German standards and fittings not UK. 

Yes I need to check if that is a step or if it's just some orange pipe fitted over the existing pipe because there was a small hole in the top.

 

5 minutes ago, TonyT said:

He’s not a plumber, he’s a chancer

time to bin him and find some decent trades before this  buried and causes you no end of problems 

What would the ideal solution look like? Thanks

[TonyT]

Ah didn’t appreciate you were in Germany.

 

will take some of my comments back, maybe not, still looks rough..

[vagrantly3893]

2 minutes ago, TonyT said:

Ah didn’t appreciate you were in Germany.

 

will take some of my comments back, maybe not, still looks rough..

Yeah I thought he would replace everything from the house to the existing long grey pipe. But I wasn't there today to discuss with him.

[Dave Jones]

if it was England, all they grey shite needs ripping out and replacing with underground drainage to a proper fall with a chamber on any change in direction. 

[Conor]

12 hours ago, vagrantly3893 said:

Yes I need to check if that is a step or if it's just some orange pipe fitted over the existing pipe because there was a small hole in the top.

 

What would the ideal solution look like? Thanks

 

All the grey pipes and joints replaced with orange. An inspection chamber where the bend is. Pipes supported on a bed of fine stone <10mm (or whatever the local requirement is) and covered with same before backfilling. Tbh it's more of a job for a groundworker than a plumber. No offense to any competent plumbers reading this 🤣

 

It'll cost you more now, but will save you the hassle of digging it all up again in a few years time.

[vagrantly3893]

On 08/08/2023 at 09:50, Conor said:

 

All the grey pipes and joints replaced with orange. An inspection chamber where the bend is. Pipes supported on a bed of fine stone <10mm (or whatever the local requirement is) and covered with same before backfilling. Tbh it's more of a job for a groundworker than a plumber. No offense to any competent plumbers reading this 🤣

 

It'll cost you more now, but will save you the hassle of digging it all up again in a few years time.

 

Thanks. The existing grey sleeve is still dripping a little. A drop every couple of seconds. So my plan is to replace the grey inspection chamber with this:

 

 

And replacing the grey sleeve with this:

 

 

Where the connections are made, is a seal also required?

 

Edited August 11, 2023 by vagrantly3893

[Conor]

do it right:

 

https://www.drainagesuperstore.co.uk/help-and-advice/product-guides/underground-drainage/what-is-an-inspection-chamber/