Sunlight and external twin & earth

I'd be interested in the answer to that. I'd just comment that conduit always looks better, bare cable just looks like a bodge to me.

IME of several lengths exposed for decades, no harm results to the outer sheath. I have one disused piece which has the inner exposed for about 10 years now, and the sun has almost bleached the red and black colours out, but it's all still just as flexible as it was. The material is going to vary from different manufacturers, and it may be that you can find some which isn't UV stable.

Painting would add further protection. Use oil-based gloss topcoat directly onto the PVC (with no undercoat). Don't use more than you need, because the solvent does slightly dissolve into the PVC surface until it dries (so the paint will never peel off). Suggest you slide some paper/card behind just whilst brushing, to avoid painting the wall.

I frequently terminate the T&E in a conduit box where it leaves the house (eg)

and then use flex to the lamps. The conduit box and flex colour I use matches the colour of the lights.

Adam

You're adding to the circuit so this is notifiable.

There's masses of externally run T&E and its fine in practice. Its no longer regs compliant though. Gloss topcoat can keep the UV off, though I'm not sure that white would. Now you're meant to use armoured cable, trunking, or burial in the wall, in case it gets pruned.

NT

There is no regulation or formal guidance to that effect as far as I know.

Perhaps my original post was unclear.

These will be lights attached to the outside wall of a house.

The lighting circuit to be extended is not an extension from a kitchen or special location. The circuit is protected by an RCD. (TT system, split board, both sides have RCD protection.)

In article , The Medway Handyman writes

Depends on the conduit. That white square trunking with the clip-on lid looks awful when used externally. Short vertical lengths, painted over to match the wall, look okay, but horizontal lengths just don't look right and scream "BODGE!!!!"

Except that since no-one's ever going to question it's existance, provenance or date of fitting, so why bother drawing attention to it?

You can extend existing circuits all you like and its non notifiable (special locations excepted).

To quote (table 1 - further guidance notes):

"i. The installation of equipment attached to the outside wall of a house (for example security lighting, air conditioning equipment and radon fans) is not notifiable provided that there are no exposed outdoor connections and the work does not involve the installation of a new circuit or the extension of a circuit in a kitchen or special location or associated with a special installation."

Please cite your source for this statement. Adding to an existing circuit in an "ordinary location" generally constitutes minor works, however correct verification and testing are still required and in thoery you should write yourself a minor works certificate.

Well it looks like I fell foul of the John Prescott brigade when I stated this. They claim that anything other than changing a switch or lighting fitment, where there is NO change to the original circuit is ok, but anything which involves a change to the circuit is a definite no no without notifying the LBA and getting the appropriate tests and checks done by a certified sparks.

I hadn't seen the quoted section of the Part P document and I am really surprised that this type of work is officially sanctioned for DIYers.

In message , ARWadsworth writes

Yes, either that or some of the flexible tubing/conduit. Definitely more 'professional' than just running T&E which always looks like you've had Butch n Sundance doing jobs for you.

ALL electrical work is sanctioned for DIYers.

Some of it should be inspected by a LA if you are not able to "sign off" the work yourself.

The main arguments seem to arise over the details of what jobs are included in "some", and usually occur between those that have read part P and those that have not!