Ideal loft cable routing

[syne]

I've looked on the search and around the web but can't get much of a conclusive answer.
When installing a ring final in a loft is there an ideal/best route for the cable run?

should it be all under the floor and rise to each socket?
Run round the rear side of the dwarf walls in a literal ring, clipped to the back of the purlin, to the stud work, in conduit or not? etc etc

It's a single ring direct from the cu with no spurs, in a very simple loft conversion in a semidetached, no dormer or bathroom.
Is there an actual method preferred by electricians?

 

[EFLImpudence]

It's up to you really as long as it is safe.

Is it a house or bungalow?

There isn't much point having a ring for a loft with the presumed height and waste of cable going back down to the CU.

 

[Taylortwocities]

Run round the rear side of the dwarf walls in a literal ring,

That how I've always done it. Nice and easy, up behind the plasterboard and into the box.
PS How can a ring be described as 'literal', either its a ring or it is not.

 

[penguin16]

I assume by literally ring he means a circle.

 

[syne]

It's a house, the reason for a separate ring is, it's a nice straight run down a void to the cu and that has enough spare capacity. It's only a couple of meters further than the point where you'd break into the ring so not too much extra cable wise.

As for literal ring, well I suppose that's the difference between ring and loop..
Would you bother with conduit? Or clips to rafters?

 

[seasickstevie]

... perhaps more a 'rectangle' (?)

 

[syne]

Yes, definitely rectangular.
Out of curiosity what would you guys charge for this?
Loft is roughly 7x4m with 8 double sockets straight from cu
A three way switched light for stairs
A two way switched for 4 down lights
No access problems, no insulation in yet just framing and floor.

Only asking because the bc non competent charge is £225 (then + materials cost)

 

[Taylortwocities]

Clip to rafters.

Its notifiable work, so you probably will save money by engaging a sparky who is happy to oversee your DIY wiring and do the test, cert and notification.

 

[ban-all-sheds]

It's a house, the reason for a separate ring is, it's a nice straight run down a void to the cu and that has enough spare capacity.

That sounds like a fair-enough reason to choose to have a separate circuit.

But does not answer the question "why a ring?".

 

[syne]

Do you mean as opposed to a radial circuit?
I couldn't give a reason, well not one that would satisfy a sparky...

From what I've gathered, a ring is arguably yet slightly better than a radial because of the two returns, a bit of redundancy is created should a part of the circuit be damaged.. er maybe.

Is there a worthwhile reason to not have a ring?

 

[Taylortwocities]

With a radial you use half the copper. And it's pointless to have a ring for moderate loads, like your needs.

The problem with rings is that that a broken conductor can go for decades without being detected.provided the cable doesn't overheat due to too much current.
With a radial, you'll know there's a problem straight away.

EDIT:
And a radial is more European

 

[EFLImpudence]

Do you mean as opposed to a radial circuit?

Yes.

From what I've gathered, a ring is arguably yet slightly better than a radial because of the two returns, a bit of redundancy is created should a part of the circuit be damaged.. er maybe.

The trouble is that redundancy goes undetected and could lead to overload on the remaining circuit.

Is there a worthwhile reason to not have a ring?

Is there a worthwhile reason to have a ring?

The only reason today for installing a ring circuit is if the first and last accessory is near the supply.

 

[ban-all-sheds]

Do you mean as opposed to a radial circuit?
I couldn't give a reason, well not one that would satisfy a sparky...

That doesn't fit well with you deciding that it's OK for you to do electrical installation design....

Is there a worthwhile reason to not have a ring?

It's a struggle to come up with many worthwhile reasons to have one.

 

[syne]

The trouble is that redundancy goes undetected and could lead to overload on the remaining circuit.
Is there a worthwhile reason to have a ring?

The only reason today for installing a ring circuit is if the first and last accessory is near the supply.

The first/last is near the supply, but that might not be reason enough it seems, likely loading doesn't especially warrant it even if I am a fan of a good ole three bar fire but I do love to feel all intercontinental.

 

[ban-all-sheds]

I am a fan of a good ole three bar fire

How many of them do you plan to use in the loft at the same time?