Safety of Electrical Wiring

[johnhh43]

I have lived in my house since 1973 (when it was built). The electrical wiring has a flat grey plastic covering. After 37 years, should the house be rewired even though there are no obvious problems ? I am currently considering insulating the attic, but because of the electric cabling in the attic, I am wondering whether it would make sense to rewire first.

Ideally, I would prefer to avoid the cost of rewiring, but I suppose there may be problems lurking somewhere in the system.

I should very much appreciate any advice regarding age of wiring and replacement need, and a procedure I should follow.

Regards

 

[ban-all-sheds]

1) If you've been there since it was built you should know if any potentially sub-standard fiddling about has been done to the wiring

2) If run at maximum loading 24 x 365 the cables should have a lifespan of at least 20 years. Yours won't have been run at anything like that, in fact most of them have probably never had the full load applied, and none of them will ever have had it applied for more than short periods, e.g. shower, cooker starting up all rings and oven from cold, W/M, T/D & D/W all coinciding etc.

3) Nevertheless, after 37 years it would be prudent to get an electrician to carry out a Periodic Inspection.

4) In any event you should get professional advice on the effect of insulation on the cables in the loft - lighting will probably be fine, but if you have a shower cable up there, or one supplying a wall mounted heater then those may need special consideration.

 

[Steve]

If it were me doing the loft insulation etc, I'd rewire the upstairs lighting circuit in PVC conduit. I'd toy with the idea of attaching the conduit high up to the rafters, and providing flex drops to the lights and switches through the insulation. This way, all joints remain accessible and you wont be fumbling through insulation in years to come, to get to that hidden junction.

If the shower circuit runs through the loft, I'd definitely run that high in PVC conduit the whole route, including the drops.

 

[electronicsuk]

If it were me doing the loft insulation etc, I'd rewire the upstairs lighting circuit in PVC conduit. I'd toy with the idea of attaching the conduit high up to the rafters, and providing flex drops to the lights and switches through the insulation. This way, all joints remain accessible and you wont be fumbling through insulation in years to come, to get to that hidden junction.

Agree that it's wise to keep the wiring out of the way of the insulation, but cable tray would be a more reasonable way of doing so.

 

[Steve]

If it were me doing the loft insulation etc, I'd rewire the upstairs lighting circuit in PVC conduit. I'd toy with the idea of attaching the conduit high up to the rafters, and providing flex drops to the lights and switches through the insulation. This way, all joints remain accessible and you wont be fumbling through insulation in years to come, to get to that hidden junction.

Agree that it's wise to keep the wiring out of the way of the insulation, but cable tray would be a more reasonable way of doing so.

You mean just above the insulation? Perhaps. My reasoning was that people often throw things into the loft from down below (I do anyway) and plastic conduit run along the insulation could get damaged.

We're having the roof replaced next month, including an extra blanket of insulation in the loft. I have a week off, I'm going to empty the loft and do a bit of re-wiring of the lighting up there. Unsure how to proceed really though. It would help if I knew if they were replacing the roof timbers or not*


*Standard disclaimer: All work will be notified as per the requirements of Part P.

 

[electronicsuk]

You mean just above the insulation? Perhaps. My reasoning was that people often throw things into the loft from down below (I do anyway) and plastic conduit run along the insulation could get damaged.

I was thinking more along the same lines as you, tray attached to parts of the roof truss, with wiring cable tied on. You could use basket tray the correct way round if you manufactured suitable brackets and then just lay the wiring in, but it seems like a lot of hassle. However, I have seen a photo on here of tray laid directly on top of loft insulation, and it's still a lot better than just leaving the cables trailing about with no real support.

*Standard disclaimer: All work will be notified as per the requirements of Part P.

 

[Steve]

*Standard disclaimer: All work will be notified as per the requirements of Part P.

You part p?

 

[electronicsuk]

*Standard disclaimer: All work will be notified as per the requirements of Part P.

You part p?

Word certainly gets around when you speak to Adam, eh?

 

[securespark]

Yeah, tray's better.

It'll keep the cable claer of the loft ins, but you don't incur a derating penalty like conduit or trunking.