Wiring Convention?

[Andy]

Might be a silly question this but is there a standard convention concerning the routing of wires in a house? I would like info specifically on light switches; so if I am looking at a light switch in my lounge, would the wires go straight up, straight down or what? Are the upstairs switches different? My house has a concrete floor so the wiring cannot go under the floorboards - don't know if that makes a difference or not.

The reason I ask is that I need to do some drilling and although I will use a cable detector first, I would like to avoid any obvious pitfalls.

Many thanx,

Andy.

[Owain]

"Andy" wrote | Might be a silly question this but is there a standard convention | concerning the routing of wires in a house?

Yes. But don't rely on it :-)

| I would like info specifically on light switches; so if I am looking | at a light switch in my lounge, would the wires go straight up, | straight down or what?

Wires may be run

horizontal or vertical from an accessory or within 150 mm of the top (but not the bottom) of a wall or within 150 mm of the angle formed by two adjoining walls

Cables may be run diagonally but must then be protected eg being in conduit or having an earthed metal sheath eg mineral insulated cable.

Owain

[Andrew McKay]

The convention, for what it is worth, is straight up or straight down. Except where the electrician has been inventive.

Downstairs light and socket fittings are invariably dropped from above in my experience - but that doesn't mean they should be in every case. Upstairs is pretty much the same game plan.

But use that metal detector to make sure!

Andrew

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[Mike Ring]

[e-mail] (Andy) wrote in news: [e-mail]:

I would like info

Yes, the wires will go straight up, (0r possibly down if the floor's not concrete, check how they leave the back box) and so should all fittings; I believe some short horizontal runs are allowed for spurs etc, but I don't know the regs.

Try not to be a silly billy like me when fitting wall lights and nearly drill through the cables because I somehow forgot - it was a daft place to put a mounting hole anyhow!

Mike R

[Martin Angove]

Or at least, they *should* do (On Site Guide fig 7.3.2 p53). Don't take it for granted that they actually do, especially if any previous owner has done work on the system.

Hwyl!

M.

[Nigel Mercier ®]

Either.

[David]

Can anyone tell me the reasoning for this? I can understand no diagonals unless shielded, but is it just so people can make an educated guess about where the wires are?

And also, why not in the bottom 150mm? Is it to protect against flooding?? If so, I would have though you would be in enough trouble anyway if the water got even close to there and the cables were run under the floorboards!!

David.

[Martin Angove]

Probably. I think there used to be a requirement to protect all cables buried in plaster, but now, so long as you stay within the guidelines you can bury them "bare".

Probably to avoid skirting board nails being hammered through your ring main every 3 ft. :-)

Hwyl!

M.