Level of soil pipe/foulwater drain?

[CalvinHobbes]

Hello, a wee question. On the photo below you will see where we had to dig out the old clay pipe. The old entrance will be getting a retaining wall and hard core will go in topped with clay so it matches the level of the rest of the garden.

At the other side of the plot, in my sisters plot there is what I think is a backdrop drain (also clay and needs replaced).

So would you put the soil pipe higher up in our former drive with a backdrop drain or would you renew the old one and cover it at that level?

Incidentally we must have half a dozen robins dive bombing every time the digger bucket moves, coming back up with mouthfuls of worms.

Edited January 23, 2023 by CalvinHobbes

[CalvinHobbes]

Bumping in the hope someone with ground working knowledge will see. Our digger man had an accident at the weekend (not on site) so would just like to check this.

[markc]

Assuming the connection is under the pavement then you might as well keep it deep till the first chamber. Then assess runs and depths needed from the build/s and put their chambers in to suit. Bit of extra digging is much easier and less stress than working with shallow drains

[Conor]

Runnat original depth. Bear in mind minimum cover for building control. Also, a deeper pipe is less likely to be struck in future. Also allows you to run other services on TOP, in the same tewmxh, if needed.

[CalvinHobbes]

Thanks, historically we have had issues at the bottom with blockages. I think the issue is the gradient, bluntly I suspect the water runs too fast and solids get a chance to harden. I will ensure they check it today and if necessary do a backdrop. I have been look at part h regs too. 

 

[CalvinHobbes]

Also there is an old clay pipe under road we are joining with the new pvc, I am wary of doing it with cement as I have seen before. Will measure and go to plumbers merchants. 

[Conor]

Just FYI you'll need BC out to inspect before you fully backfill. They need to see depths and adequate bedding etc.

[CalvinHobbes]

Thanks for the heads up Conor. I thought this was just replacement so they wouldn't have to. 

[Conor]

Take photos just in case. They'll be more interested in the drainage around the house and under driveways etc

[Blooda]

21 hours ago, Conor said:

Take photos just in case.

With a tape measure / staff to show depth.

[Dave Jones]

if your wanting any sort of build warranty then drain tests will need to be carried out and the results provided as well. Not that hard to do and the kit can be bought for under £30.

[CalvinHobbes]

Just had a chat with the building control officer who was supposed to be coming out on Monday (I delayed it). It was very helpful. So now going to go back to the architect and ask for the drainage plan.  It just has felt too on the hoof. I know,fail to plan, plan to fail.

[CalvinHobbes]

So onsite So onside and looking at the retaining wall with drain at bottom. So fill will be 180cm and i know we need an inspection chamber with risers and a restricted lid behind the wall. Can anyone tell me what the layers are above? How much pea shingle do you use? Can I use any rubble before the earth?  

[CalvinHobbes]

Also when I say rubble, what is the max size of bit of rubble? Can a full brick go in? Or is it just pea shingle until the earth? Sorry for the bad terminology. 

[CalvinHobbes]

Bumping this in hope. 

[Mr Punter]

I have used the band seal couplings to join pipes of different materials.  Lay the new pipes on a 50mm bed of shingle.  When all the pipe is in, cover in more shingle, then use your excavated material.  No big sharp bits that could damage the pipe.

 

BTW the thing about solids being left behind on a steeper drain run has been debunked and there is now no maximum gradient.  An IC is required for a change in gradient or direction.