Loft lighting - wiring regs

Afternoon all!

What are the regulations for putting a couple of pendants and a switch in a loft? They'd be wired from a loop in a rose.

What I'm getting at is, is it acceptable to cable clip the T&E to the joists, or do they need to be put in trunking etc, like main areas of the house?

Cheers

Euan

Originally Posted by EWebster

Afternoon all!

What are the regulations for putting a couple of pendants and a switch in a loft? They'd be wired from a loop in a rose.

What I'm getting at is, is it acceptable to cable clip the T&E to the joists, or do they need to be put in trunking etc, like main areas of the house?

Cheers

Euan

Hi Euan,

I think the main consideration is one of building regs, in that the cabling should not be placed in a location susceptible to mechanical damage, i.e. the top of the joists.

Therefore, I think that you should run the cable along (clipped) the sides of the joists and rafters.
Furthermore, you need to consider installation methods, 101, 102 etc and derate current carrying capacity of cables dependent upon method of installation.

Yooj

do they need to be put in trunking etc, like main areas of the house?

Must say I can't remember what reg this is, can anybody oblige?

The problem lies with not knowing what will happen next. The homeowner could come along afterwards and board out the rafters and cover the cabling, or cover in insulation...............
Basically Id clip direct provided there was RCD protection and make this clear on your minor works.......

Although regs always apply, whats the loft going to be used for, eg storage, play room office?

Originally Posted by johnnyb

Although regs always apply, whats the loft going to be used for, eg storage, play room office?

Going to be used for storage. It's an old consumer unit, so no RCD, and they certainly won't want to replace it to get an RCD just for a couple of loft lights unfortunately.

Originally Posted by Graeme Harrold

The problem lies with not knowing what will happen next. The homeowner could come along afterwards and board out the rafters and cover the cabling, or cover in insulation...............
Basically Id clip direct provided there was RCD protection and make this clear on your minor works.......

Why do you need Rcd protection in a loft

Originally Posted by Mac

Why do you need Rcd protection in a loft

You don't. But with 17th Ed, all circuits that are not buried more than 50mm in a wall, or protected by mechanical means (i.e. metal conduit) need to be RCD protected, I believe.

Originally Posted by EWebster

You don't. But with 17th Ed, all circuits that are not buried more than 50mm in a wall, or protected by mechanical means (i.e. metal conduit) need to be RCD protected, I believe.

Sorry mate,how many times have you been in your loft this year,once or twice.Only time i go up there is get the cases and Xmas decorations down and vice versa.Personally i dont see a problem

Originally Posted by EWebster

You don't. But with 17th Ed, all circuits that are not buried more than 50mm in a wall, or protected by mechanical means (i.e. metal conduit) need to be RCD protected, I believe.

the quote is not quite right, "cables buried less than 50mm deep in a wall ..." If it's not buried then it does not require an RCD. (this is not an exact quote but reflects the requirement)

The distinction comes in the type of CU installed. It would be within regs to extend the loft lighting on an old box with no RCD.

I still don't think there is a requirement to place all cable in truncking in the main house unless suseptible to mechanical damage. Otherwise the wireing method "clipped direct" would not exist.

Yep, clipped direct, no RCD requirement (assuming it is lighting only and no sockets).
You might want to consider a metal-clad surface-mount switch and box.

Yooj