Permanent outdoor water supply to end of garden

[nic]

I'm having some major landscaping work done to the garden and I want to take the opportunity to put in a permanent water supply to a polytunnel (for growing veg), which will be installed at the end of the garden.
The garden is about 30m long, with a slight uphill gradient away from the house (about 1m over the whole length).
The water pressure in the house is reasonable as all the internal pipes and mains supply line have recently been replaced (direct unvented system).
I have a single external tap at the rear of the house.
We have a large area of decking at the rear - it's possible to take up some of the planks if necessary to pull pipes through.
Beyond that we currently have an area of grass that will be dug up and replaced by artificial turf.

Ideally I would like to bury a pipe along the side fence from the end of the decking to the polytunnel, when the new turf is installed. I would then run another length of flexible hose under the decking to connect to the pipe at one end, and install a tap at the other end.

• Is this feasible in general given the length of pipe required and slight gradient? I'm assuming if I used a larger diameter pipe it would minimize the impact on the pressure.
• What is the best type of pipe to use? Would something like a 25mm MDPE mains supply pipe be suitable and flexible enough to bury and carry on under the decking so I don't have to join?
• What is the best way of connecting the new pipe to the existing and new taps?

Many thanks in advance

 

[SimonG]

750mm deep, blue alkathene.

 

[glenntaf]

If you go to a good plumbers merchants you can get all sorts of fittings for MDPE pipe, including ones that will connect copper to MDPE. Just be aware you may need inserts when you make of the joint. Also make sure you bury the pipe deep enough to avoid it freezing and rupturing.

 

[rpm]

Another "Bed in the Shed" job is it?

 

[joni os]

Come off existing, in house, with internal isolation and check valves as if doing outside tap. After that protection against frost and damage. Would not bury pipe on fence line as future excavation for post holes could damage .Better bury half metre inside fence line.

 

[Riley]

750mm deep, blue alkathene.

But no deeper than 1350