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