What is the correct way to spur off a ceiling rose on a normal ring circuit?

[EasyGoingPat]

2.5 cable, spurring from a rose on a normal ring?
Using such terminology, I must admit, I'm hoping OP has some serious engineering skills and isn't taking the pee.

Well, I once built a computer from the level of individual resistors and capacitors but, as I said, I am not familiar with domestic wiring regs. Hence my question, based on the knowledge that these higher voltages and currents can be dangerous. But, yes, as soon as I'd made the post and gone in the loft to do the actual work, I did realise that it was a bit silly. One glance at 2.5mm cable made me realise that I'd have to be powering a garden full of halogen lights for that to be necessary. On closer inspection, the lighting ring is indeed 1.5mm.

 

[littlespark]

Its just the wrong terminology.

A "ring" is normally used with sockets, where a twin and earth cable leaves the fuseboard, drops off at every socket on the circuit with a "one in, one out" and returns to the fuseboard, hence a ring circuit.

A lighting circuit, and most others are "radial" like the branches of a tree.

With low energy lamps, 1.0mm is much more common now