Ducting the service pipe

[ACDC]

I'm laying a new MDPE service pipe to replace the old lead one, and I have no choice but to pass it under a sewer pipe. I see from the regs that it has to be ducted for 1m either side. What form dose the ducting have to take? Can I simply pass the mdpe through a slightly large pipe?
Thanks
ACDC

 

[Gasguru]

We laid 3 new MDPE's a kilometre across farmland last year - used the cheapest ducting we could find - water company were OK about it. I don't think they specified the size.

 

[Agile]

I assume you are both talking about water?

If the pipe is at least 750 mm deep and this will be 300 below the deepest ploughing depth then I dont see any need for any ducting. Why was it required?

Tony

 

[Gasguru]

The OP requires ducting due to close proximity to other services.

When laying the pipe it can either be ducted or bedded on soft sand (and then part backfilled with sand).

In my case using sand had its problems eg. transporting several tons across fields where the water table was high can be difficult and damaging (especially if you don't own the land).

There is also the problem of increased spoil and cost of removal.

If ducting can be obtained cheaply (especially offcuts) it can be a viable alternative.

 

[chrishutt]

.....laid 3 new MDPE's a kilometre across farmland last year - used the cheapest ducting we could find ....... ducting can be obtained cheaply (especially offcuts)...

3,000 metres of offcuts!

 

[ididdidi]

So long as you dont go below 1350mm deep is another reg to bear in mind were not miners, not sure about the duct material though?

Cheers

 

[ACDC]

So can I simply pass the 25mm MDPE through another pipe of slightly greatler diameter? Do I need to seal the ends with anything?

 

[Gasguru]

Regulation 7.8c shows a ducted pipe running beneath a stream. It mentions using a 75 or 100mm duct to allow removal/replacement of the main. I think this is excessive but it does require the annular gap between duct and pipe to be sealed at each end. Since there is no specific mention of soil pipes I would check with the water company before laying to avoid re-doing.

Your main will also require ducting and sealing as it passes through the house foundation (regulation 7.2). in addition any main passing through a ventillated floor void must also be insulated