Rewire Upstairs Lighting

[AbneyTeal]

Hi, I'm in the process improving our recently bought 1930's 3 bed house. The loft has been completely cleared out to spray woodworm treatment, but before the insulation back goes down, I thought this would be a good time to rewire the upstairs lighting. I should point out I'm only a DIY'er, but a very careful one! Currently the electrics in the loft consist of 1 junction box with all the light and switch cables coming out from it. I thought I could replicate the current layout using 1.5mm twin and earth cable, replacing the old red/black cabling. Would it be ok to use this layout?


In addition to this, all the walls in the house are brick & plaster with the cables placed in steel conduit. I was thinking of fitting the new cables down the old conduit to the switches as its only a short distance, they should go down it fine. In the loft, the conduit terminates level with the top of the joists with the cable looking vulnerable to damage. Would cutting these level with the laths & removing the burr with a file make more sense? Would like to also replace the switch back boxes as the current ones are an older style with the thread at the back, they're a pain to screw into.

I used to do plastering many years back, so any damage in that department can be easily rectified. We plan to get a spark in eventually to change the consumer unit as it looks a bit old (80's, 90's), also to check the electrics in the rest of the house. At the moment I just need to get my loft insulation back down!

Thanks

 

[DNS1]

I'm afraid that as the first one on this thread, I'm going to have to point out that replacement of circuits by a DIYer is not allowed unless you inform local council building control first and pay them a reasonable amount of money to check the work and certify it.

Sorry, but you really need to get a sparks in straight away to do all the work. If you can plaster up yourself afterwards then you can definitely save money that way, but you're just not allowed to do a rewire yourself.

Where are you? Maybe someone on here can pop by and give you a quote.

 

[telectrix]

as above. also, not a good idea to spider wire from a single junction box, and allowance needs to be made for insulation. for what you would have to pay building control to notify the job, you could get a qualified spark to do the job safely and legally. i agree that using the existing conduit is viable, but bear in mind that the circuit would require RCD protection as well in order to comply with current regs., just to complicate matters. if you post your location, i;m sure a member of the forum is close to you and could sort it out at reasonable cost.

 

[Guitarist]

In addition to what has already been said, if it is proper conduit which can be earthed, then you may be able to reuse it. However, I have often found what looks like steel conduit to be nothing more than metal pipework which has been used to protect the cable and is impossible to get a good connection to. In that case, it may need to come out anyway.
Also, how do you intend to test the circuit afterwards to BS7671 1st amd?