Firstly I'm in Scotland so water metering is not a consideration.
I've considered using rainwater recycling for the tunnel, but will be
faced with a soakaway to cope with the winter rains so I see no point
in putting in a tank and a soakaway.

To get at a mains supply is going to be awkward, but if my memory of
the bathroom underfloor configuration is correct, not impossible.

What I need guidance on is what sort of piping to use. The run to the
tunnel will be about 10m underground from the house wall - there is I
think a suitable hole under the wall of the house (it's a stone
cottage, 3ft thick walls and no founds) which will give access under
the bathroom where there is a mains supply. I can just squeeze into
part of that area under the bathroom floor, but will need a pipe with
maximum flexibility to get it through the hole under the wall, under
the bathroom and then back up under the sink where there is mains.

Many thanks for any help - all the plumbing I have done in the past is
in copper and I've never used plastic. It's probably ideal for this
situation but can I use just one type of pipe for the whole run?

Rob

On 21/09/2012 23:00, robgraham wrote:
Firstly I'm in Scotland so water metering is not a consideration.
I've considered using rainwater recycling for the tunnel, but will be
faced with a soakaway to cope with the winter rains so I see no point
in putting in a tank and a soakaway.

To get at a mains supply is going to be awkward, but if my memory of
the bathroom underfloor configuration is correct, not impossible.

What I need guidance on is what sort of piping to use. The run to the
tunnel will be about 10m underground from the house wall - there is I
think a suitable hole under the wall of the house (it's a stone
cottage, 3ft thick walls and no founds) which will give access under
the bathroom where there is a mains supply. I can just squeeze into
part of that area under the bathroom floor, but will need a pipe with
maximum flexibility to get it through the hole under the wall, under
the bathroom and then back up under the sink where there is mains.

Many thanks for any help - all the plumbing I have done in the past is
in copper and I've never used plastic. It's probably ideal for this
situation but can I use just one type of pipe for the whole run?

Rob


20mm MDPE pipe all the way.

50m reel from Screwfix is £28
http://www.screwfix.com/p/mdpe-blue-...mm-x-50m/83620

Assuming you are connecting to 15mm copper in the house, you will need
something like this
http://www.screwfix.com/p/jg-speedfi...0-x-15mm/44442

and possibly this to T into an existing copper pipe
http://www.screwfix.com/p/jg-speedfi...tee-15mm/50422

Or this if you want to use compression
http://www.screwfix.com/p/chrome-equal-tee-15mm/21800

you will need a shot piece of copper or plastic (with inserts) 15 mm
pipe to go between the T and the MDPE adaptor

I suggest you also fit an isolation valve under the sink so you can
isolate it.

Use a full bore one with a handle like this
http://www.screwfix.com/p/full-bore-...lve-15mm/80413

On the far end, if you want to just fir a bib tap, then youy need a wall
plate like this
http://www.screwfix.com/p/mdpe-plast...w-20mm-x/62324

And the bib tap
http://www.screwfix.com/p/15mm-x-out...ck-valve/37241

--
Toby...
Remove pants to reply

On Sep 21, 11:15*pm, Toby wrote:
On 21/09/2012 23:00, robgraham wrote:









Firstly I'm in Scotland so water metering is not a consideration.
I've considered using rainwater recycling for the tunnel, but will be
faced with a soakaway to cope with the winter rains so I see no point
in putting in a tank and a soakaway.

To get at a mains supply is going to be awkward, but if my memory of
the bathroom underfloor configuration is correct, not impossible.

What I need guidance on is what sort of piping to use. *The run to the
tunnel will be about 10m underground from the house wall - there is I
think a suitable hole under the wall of the house (it's a stone
cottage, 3ft thick walls and no founds) which will give access under
the bathroom where there is a mains supply. *I can just squeeze into
part of that area under the bathroom floor, but will need a pipe with
maximum flexibility to get it through the hole under the wall, under
the bathroom and then back up under the sink where there is mains.

Many thanks for any help - all the plumbing I have done in the past is
in copper and I've never used plastic. *It's probably ideal for this
situation but can I use just one type of pipe for the whole run?

Rob

20mm MDPE pipe all the way.

50m reel from Screwfix is £28http://www.screwfix.com/p/mdpe-blue-pipe-20mm-x-50m/83620

Assuming you are connecting to 15mm copper in the house, you will need
something like thishttp://www.screwfix.com/p/jg-speedfit-ug601b-mdpe-copper-adaptor-20-x...

and possibly this to T into an existing copper pipehttp://www.screwfix.com/p/jg-speedfit-equal-tee-15mm/50422

Or this if you want to use compressionhttp://www.screwfix.com/p/chrome-equal-tee-15mm/21800

you will need a shot piece of copper or plastic (with inserts) 15 mm
pipe to go between the T and the MDPE adaptor

I suggest you also fit an isolation valve under the sink so you can
isolate it.

Use a full bore one with a handle like thishttp://www.screwfix.com/p/full-bore-lever-ball-valve-15mm/80413

On the far end, if you want to just fir a bib tap, then youy need a wall
plate like thishttp://www.screwfix.com/p/mdpe-plastic-wall-plate-elbow-20mm-x/62324

And the bib taphttp://www.screwfix.com/p/15mm-x-outside-tap-with-check-valve/37241

--
Toby...
Remove pants to reply

Many thanks Toby - I couldn't have asked for a more fulsome reply.
I've got some MDPE blue pipe but can't remember (at 11pm) what
diameter it is - one thing that does concern me is that it is not that
flexible, so let's hope it's the larger diameter stuff and that the
20mm is easier to work with.

Rob