I'm just getting back into the DIY mind set and rooting around in the shed
to dig stuff out of my stash.

I'm extending the 13A ring in the 3rd bedroom/office, and need to run two
2.5mm T&E wires through the joists. Ring out, and ring return.

I've put my digital callipers on the T&E and it is perhaps a whisker under
10mm wide.

I assume that a 10mm hole would be just adequate to pass a single wire.

However I do have a 16mm spade wood drill as well.

Would it be acceptable/better to drill a single 16mm hole and run both
wires?

Cheers


Dave R



--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64

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On 26/06/2019 18:30, David wrote:
I'm just getting back into the DIY mind set and rooting around in the shed
to dig stuff out of my stash.

I'm extending the 13A ring in the 3rd bedroom/office, and need to run two
2.5mm T&E wires through the joists. Ring out, and ring return.

I've put my digital callipers on the T&E and it is perhaps a whisker under
10mm wide.

I assume that a 10mm hole would be just adequate to pass a single wire.

However I do have a 16mm spade wood drill as well.

Would it be acceptable/better to drill a single 16mm hole and run both
wires?

That's what I've done - and in some cases 20mm with two, plus a couple
of lighting wires.

Yes they are all together and that affects how much heat they can lose
to the air, but it is only for a very short distance and copper conducts
heat very well, so local overheating is very unlikely, as it'll travel
along and escape elsewhere.

SteveW

On 26/06/2019 18:30, David wrote:
I'm just getting back into the DIY mind set and rooting around in the shed
to dig stuff out of my stash.

I'm extending the 13A ring in the 3rd bedroom/office, and need to run two
2.5mm T&E wires through the joists. Ring out, and ring return.

I've put my digital callipers on the T&E and it is perhaps a whisker under
10mm wide.

I assume that a 10mm hole would be just adequate to pass a single wire.

However I do have a 16mm spade wood drill as well.

Would it be acceptable/better to drill a single 16mm hole and run both
wires?


Depending on how many joists and how much cable you have to pass through
the joists is the deciding factor. I would suggest buying a new 20mm or
even a 25mm spade bit.



--
Adam

On 26/06/2019 18:30, David wrote:

I'm just getting back into the DIY mind set and rooting around in the shed
to dig stuff out of my stash.

I'm extending the 13A ring in the 3rd bedroom/office, and need to run two
2.5mm T&E wires through the joists. Ring out, and ring return.

I've put my digital callipers on the T&E and it is perhaps a whisker under
10mm wide.

I assume that a 10mm hole would be just adequate to pass a single wire.

However I do have a 16mm spade wood drill as well.

Would it be acceptable/better to drill a single 16mm hole and run both
wires?

IME its not worth messing about with holes that are "just big enough"
and "in theory" - just slap a 20 or 25mm bit hole in the joist and make
life nice and easy for threading stuff through and pulling in cable.

--
Cheers,

John.

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On Thu, 27 Jun 2019 00:43:09 +0100, John Rumm wrote:

On 26/06/2019 18:30, David wrote:

I'm just getting back into the DIY mind set and rooting around in the
shed to dig stuff out of my stash.

I'm extending the 13A ring in the 3rd bedroom/office, and need to run
two 2.5mm T&E wires through the joists. Ring out, and ring return.

I've put my digital callipers on the T&E and it is perhaps a whisker
under 10mm wide.

I assume that a 10mm hole would be just adequate to pass a single wire.

However I do have a 16mm spade wood drill as well.

Would it be acceptable/better to drill a single 16mm hole and run both
wires?

IME its not worth messing about with holes that are "just big enough"
and "in theory" - just slap a 20 or 25mm bit hole in the joist and make
life nice and easy for threading stuff through and pulling in cable.

Larger bit now being searched for in stash. :-)


Thanks to all who responded.

Cheers



Dave R



--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64

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