Water mains trench - bend radius

[John Williamson]

I'm looking to replace my water supply. I will be digging the trench on my side myself. I have all the safe dig plans etc and found the guide on the southern water website:



Slightly confused by the 750mm minimum from the outside wall. Is this an actual thing? Every stopcock I have ever seen has been secured to the wall in some way. My wall construction is solid block-work with insulated stud wall which comes to 342.5mm thick all in. This means the pipe would come up in the middle of the floor.

2nd question is if I use 32mm MDPE the minimum bend radius would be 480mm. Would I be allowed to use a compression elbow like the one in this link within the pipe lagging part after the footings so that it can come up closer to the internal wall?

Below Ground Elbow

 

[John Williamson]

Anglian water much better and give you the option to use insulation within the ducting which I was planning on doing anyway

 

[exedon2]

Have a look for INSUduct fully compliant with all regulations no hole to dig under footings!

 

[John Williamson]

Have a look for INSUduct fully compliant with all regulations no hole to dig under footings!

Thank you, I did have a look at this. I can't see them doing a 32mm unfortunately but not a deal breaker. The issue I have is that this is a listed building so anything visible outside like this would need to go through Listed Building Consent. (i.e. painful and slow)

My bad. Just seen the 32mm INSUduct External Water Supply Protection - https://store.jdpipes.co.uk/insuduct-external-water-pipe-supply-protection-box/

 

[exedon2]

We have used them on listed properties by finishing insuduct just below ground level then core drilling at a angle from inside to meet it.
We use 110mm core hole correct insulation then foam fill.

 

[ShaunCorbs]

Tbh I wouldn’t want fittings below ground unless you really have to also use some 4” drain and long radius bends to sleeve it into your house

 

[John Williamson]

We have used them on listed properties by finishing insuduct just below ground level then core drilling at a angle from inside to meet it.
We use 110mm core hole correct insulation then foam fill.

I might be missing something but I don't really get the benefit? You would still need to core drill, just one system slightly higher than the other. They also don't seem to make the 32mm hockey sticks so would force me to use 25mm.

The other problem is that the building where this is going to be is 40cm higher above ground level than the other part of the house so I don't think I would be able to achieve this without some of it being visible.

 

[John Williamson]

Tbh I wouldn’t want fittings below ground unless you really have to also use some 4” drain and long radius bends to sleeve it into your house

Yeah maybe the answer is to have a wide sweeping radius inside. Unless I can find some prefabricated 32mm MDPE hockey sticks

 

[ShaunCorbs]

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PVC GAS BENDS 90DEG 44MM OD TO SUIT 32MM PE PIPE - Gas Equipment Direct

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