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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> Rewire - wall lights https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1106514781 Message started by JohnDavies on Jan 23^rd, 2005, 9:13pm

Title: Rewire - wall lights
Post by JohnDavies on Jan 23^rd, 2005, 9:13pm

As part of my rewire (nearly there now!) I want to put a pair of wall lights in the living room run off the downstairs radial lighting circuit.

Firstly, do I need to have a feed from a junction box which is wired into the lighting circuit to another junction box which then feeds the switch and the lights, or is it o.k. to just use one junction box and feed the lights and switch directly off it- I have seen both forms of wiring in the past and was wondering which is best practice. I take it that these days the junction box should in any case be secured to a joist rather than be left loose.

secondly, the easiest route for the cables is down the other (dining room) side of the wall and then feed them through the wall to the lights, not least because I will have to replaster the dining room anyway due to loose plaster, demolishing a wall and installing an RSJ. There is also decent plaster coving in the living room which I do not want to mess with/make channels in unless absoutely necessary. However, I suspect this is not good practice because it would not be immediately apparent to someone working on the house in future that the cables are there, and that really I should run the wires in the same room as the lights so that it is obvious to anyone that there are feed wires there - opinions welcome.

Is 1mm o.k. for this - I have used 1.5 elsewhere for the lighting circuits, but it seems excessive for 60w wall lights.

Lastly, I note that according to regs. cables now have to be secured to joists and at 50mm depth when passing through a joist, whereas years ago it was normal to run them just under floorboards (!) and to leave them loose so that if rewiring one could pull through - how much trouble should one go to to do this?
Although all cables are at least 50mm from the floorbaords when passing through a joist, and I have clipped them to a joist whenever it was easy to do so, should I also go to the trouble of raising floorboards to fix the cables to joists in areas where I have managed to feed them through? If so this seems a bit strange. Again opinions welcome.

Thanks

John D

Title: Re: Rewire - wall lights
Post by L.Spark on Jan 23^rd, 2005, 9:59pm

Hi John

wrote on Jan 23^rd, 2005, 9:13pm:

Firstly, do I need to have a feed from a junction box which is wired into the lighting circuit to another junction box which then feeds the switch and the lights, or is it o.k. to just use one junction box and feed the lights and switch directly off it- I have seen both forms of wiring in the past and was wondering which is best practice.

You can't easily go wrong with lighting circuit's, the important thing is to decide how they are going to be switched, if they are being taken off other light's that are already being switched, then they will be switched with them, you can T off from an existing junction box if you like with 1.5mm or 1mm twin+earth cable.
I take it that these days the junction box should in any case be secured to a joist rather than be left loose.

Quote:

secondly, the easiest route for the cables is down the other (dining room) side of the wall and then feed them through the wall to the lights

You can run the cable's from the above ceiling void down the wall chased in directly vertical to the light, or run it from the void and then surface with Trunking, however the former is more aesthetically pleasing ;)

As long as you don't go diagonal with cable's on wall's, otherwise it's hard for people to judge where cables have been run

Quote:

However, I suspect this is not good practice because it would not be immediately apparent to someone working on the house in future that the cables are there, and that really I should run the wires in the same room as the lights so that it is obvious to anyone that there are feed wires there - opinions welcome.

That's up to you, I wouldn’t worry too much, if all the lighting downstairs’ is on one circuit, run the cables as you please, just route them properly trough centre of joists using a 20mm flat drill bit, don't notch, then run the cable from above down to your light fittings

All junction boxes should be fixed rather than 'floating'

Quote:

Is 1mm o.k. for this - I have used 1.5 elsewhere for the lighting circuits, but it seems excessive for 60w wall lights.

1mm is ok

Quote:

Lastly, I note that according to regs. cables now have to be secured to joists and at 50mm depth when passing through a joist, whereas years ago it was normal to run them just under floorboards

As I said above, cables should be run trough the joists, mark the centre of the joist and drill with a 20mm flat bit

Quote:

and to leave them loose so that if rewiring one could pull through - how much trouble should one go to to do this?

Cable's are just routed trough the holes in the joists, not fixed at any place, it does make it easier as you only need get a few board's up, you can often use old cable's to pull new ones trough etc

Quote:

Although all cables are at least 50mm from the floorboards when passing through a joist, and I have clipped them to a joist whenever it was easy to do

Not necessary

Quote:

should I also go to the trouble of raising floorboards to fix the cables to joists in areas where I have managed to feed them through?

Not necessary

Title: Re: Rewire - wall lights
Post by JohnDavies on Jan 23^rd, 2005, 10:52pm

Thanks for this - very helpful.

John D