Footings: Large lintel bridging public sewers and soil pipes

[24sevenv24]

Hi All

I am planning a rear single story extension and I have 2 public sewers which run under where I need to build. This is no issue as I have been advised by Anglian Water how they are to be protected when building over. The issue I have is my property's sewer pipe joins the main public sewer slap bang in the centre of where my footing needs to go. I would like to reuse the existing main sewer connection to avoid other admin headaches and costs with the water board associated to moving the connection. I have dug an inspection pit to expose the sewers and soil pipes and have found that my soil pipe and its connection to the main sewer is covered in a huge amount of protective concrete. My underground sewer pipe bends away from where my footing would be approximately 400mm away from where it joins the public sewer.

The easiest solution I see, to avoid cutting or breaking up any concrete near this large public sewer, is to install one large lintel over both sewers as well as the section of my underground soil pipe (covered in a huge amount of concrete) before it bends out of the way. Here is diagram of my proposal.

Please excuse the poor drawing, a proper scaled drawing will be produced if this idea is feasible.

Are gaps in footings of this size generally allowed by the inspector? Instead of a standard 600mm wide footing, I could increase this to 700mm or even 800mm for greater support or even dig deeper to 1200mm or 1400mm down.

In your experience, is this likely to be approved? What do you think?

Thanks very much in advance!

 

[jeds]

Gap in footing with lintel/s over shouldn't be an issue. This happens regularly. Where I see an issue is that connections should be accessible for maintenance - normally an access cover or rodding eyes.

My advice is put your proposal to the sewer authority and try and settle the detail before making an application for buildover.

 

[24sevenv24]

Gap in footing with lintel/s over shouldn't be an issue. This happens regularly. Where I see an issue is that connections should be accessible for maintenance - normally an access cover or rodding eyes.

My advice is put your proposal to the sewer authority and try and settle the detail before making an application for buildover.

Thankyou Jeds, I will do that. The current connection is not accessible without excavating and a man hole cover will be put in place next to the extension just after the soil pipe bend.

Thanks for your input

 

[jeds]

Try to satisfy it with rodding eyes, which can be outside the footing area. It is a negotiation and will correlate directly with the quality of the engineers breakfast. Full English and you're in. Just pray for no soggy toast.

 

[24sevenv24]

Thanks jeds

 

[mrrusty]

pee shingle is absolutely the correct material to support sewer pipes

 

[24sevenv24]

pee shingle is absolutely the correct material to support sewer pipes

I sense some sarcasm? That drawing isn't quite accurate, the sewers would remain supported by the ground underneath and a compressible material on top of some sort. I see pee shingle seems to be used a lot, or maybe fibreglass. I will ask the water board what they want me to use.

 

[Notch7]

I sense some sarcasm? That drawing isn't quite accurate, the sewers would remain supported by the ground underneath and a compressible material on top of some sort. I see pee shingle seems to be used a lot, or maybe fibreglass. I will ask the water board what they want me to use.

its pea not pee

 

[24sevenv24]

its pea not pee

Got ya! Noted