My niece's bungalow is being rewired by electricians.
While they're grooving the plaster
I may as well add some conduit for phone, internet and video.

I'm thinking of channels coming down from the roofspace,
Is there stuff I can use so we can poke down wires with the fittings
already attached,
so we can buy a standard phone extension lead and push it down or up?


http://wiki.diyfaq.org.uk/index.php?...Voltage_Wiring
says:
[For short straight runs, eg ceiling to socket or underfloor to socket,
[16mm oval conduit will generally accept a couple of networking or
[aerial cables comfortably. For a looser fit, go up to 22mm oval or 20mm
[ round.

but I guess that is just for bare wires without the plugs on the ends.


[g]

george [dicegeorge]
wibbled on Thursday 08 April 2010 22:39

My niece's bungalow is being rewired by electricians.
While they're grooving the plaster
I may as well add some conduit for phone, internet and video.

I'm thinking of channels coming down from the roofspace,
Is there stuff I can use so we can poke down wires with the fittings
already attached,
so we can buy a standard phone extension lead and push it down or up?


http://wiki.diyfaq.org.uk/index.php?...Voltage_Wiring
says:
[For short straight runs, eg ceiling to socket or underfloor to socket,
[16mm oval conduit will generally accept a couple of networking or
[aerial cables comfortably. For a looser fit, go up to 22mm oval or 20mm
[ round.

but I guess that is just for bare wires without the plugs on the ends.


[g]


I think I added that bit. Yes, without plugs[1]. When I chose to do what
you're planning, I wondered what the best conduit size would be.

I used round 20mm in few places where it was easy, but in most places the
plaster was deep enough to take oval but nothing thicker and frankly I
couldn't be arsed to hack away at the bricks more than necessary.

16mm oval tucks nicely though a 20mm knockout (bit of cable protection from
the metal hole edges, though a grommit would work too, but poking though
ensures it stays in the right place when the plasterer makes good) - so to
be sure I wasn't shooting myself in the foot, I tried a few cable types and,
provided you don't kink the conduit (gentle bends are OK):

1) TV aerial cable is fine, probably two side by side may be possible but
very tight, though most people wouldn't need two.

2) 2 Cat5E cables are fine. cat6 and cat7 untested...

3) 2 or 3 core mains flex (6A IIRC) - handy for dropping extra low voltage
power to something if T+E is too stiff, eg some types of electronic
thermostat.

4) Any size of T+E upto 2.5mm2 for sure (I used 20mm and 25mm round where I
knew bigger CSA cable was needed).

I hope you told the sparkies to stick the T+E in oval conduit too for the
tuppence-ha'penny it costs... You'll probably never benefit, but the day a
drill goes through that cable you'll be glad

[1] Two ways around this: buy or borrow suitable crimps or solder/crimp a
joint into the cable and hide it in the backbox. With network cables (as in
carrying ethernet at 100 or gig speeds) jointing is often not a good idea,
but you *can* use a Krone splice block which is an IDC punchdown for two
network cables and get predicable performance - Krone is a bit like the back
of a BT socket. OTOH, why not just punch down the cable into the back of a
proper Cat5 plate and plug the device in? For a few, you can manage with a
crappy plastic phone IDC tool perfectly well as opposed to the offical metal
punch-n-snip device.

For phone lines, solder or crimps and heatshrink is fine and not hard. If
you really want to poke plugs down, that will be 20mm round at least I
reckon. You could nip into B&Q as I did and try a few combinations...

HTH

Tim

--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.

On Apr 8, 10:39*pm, "george [dicegeorge]"
wrote:
My niece's bungalow is being rewired by electricians.
While they're grooving the plaster
I may as well add some conduit for phone, internet and video.

I'm thinking of channels coming down from the roofspace,
Is there stuff I can use so we can poke down wires with the fittings
already attached,
so we can buy a standard phone extension lead and push it down or up?

http://wiki.diyfaq.org.uk/index.php?...Voltage_Wiring
says:
[For short straight runs, eg ceiling to socket or underfloor to socket,
[16mm oval conduit will generally accept a couple of networking or
[aerial cables comfortably. For a looser fit, go up to 22mm oval or 20mm
[ round.

but I guess that is just for bare wires without the plugs on the ends.

[g]


When the conduit's fitted, put all the cables you want /outside/ of it
and plaster over. Then you've got all your first batch of cables there
plus space for more as well later.


NT