Isolating mains wire for plasterboard replacement

hessodreamy

I've got a plasterer coming to put in some new plasterboard on a wall with a mains socket. I've already ripped off the old plasterboard so the socket is loose. When he fits the new board he'll want to pull the cable through a small hole so I need to remove the wires from the socket while he works. What do I need to do to make it safe? Wago blocks? 

I could just turn off that fuse and run an extension from downstairs for the power he'll need, but if there's a more elegant solution I'll use it.

ThisIsWeird

Won't the still-socketed wire pass through the new cut-out hole? Ie, sideways.

hessodreamy

ThisIsWeird said:

Won't the still-socketed wire pass through the new cut-out hole? Ie, sideways.

Would have thought we'd be mounting the socket on the new plasterboard, so only a hole big enough for the wire would be necessary. I could be wrong though.

Section62

hessodreamy said:

ThisIsWeird said:

Won't the still-socketed wire pass through the new cut-out hole? Ie, sideways.

Would have thought we'd be mounting the socket on the new plasterboard, so only a hole big enough for the wire would be necessary. I could be wrong though.

The best thing is to have a conversation with the plasterer so you both know what you are doing before they start work... otherwise they may do it the way they think you want it, which will leave you with a less than ideal outcome.

Was the existing socket in a plasterboard-type box, or surface mounted, or in a metal back box embedded in the wall?  A photo might help.

FreeBear

hessodreamy said:

I've got a plasterer coming to put in some new plasterboard on a wall with a mains socket. I've already ripped off the old plasterboard so the socket is loose. When he fits the new board he'll want to pull the cable through a small hole so I need to remove the wires from the socket while he works. What do I need to do to make it safe? Wago blocks? 

I could just turn off that fuse and run an extension from downstairs for the power he'll need, but if there's a more elegant solution I'll use it.

I've used a length of 30A terminal strip to temporally terminate a ring main. Wrap a bit of insulation tape round the block for a little bit more protection and then tuck the whole lot in to the back box. But I'm guessing you will be using drywall boxes - Ideally, they need to be fixed in to the plasterboard before the skim coat is applied. But the cutouts are unlikely to be big enough to thread the cables AND terminal strip through..

Isolating the circuit in question by flipping the circuit breaker (fuse) will leave the neutral connected - If you have an RCD, as soon as that neutral is touched, the RCD will trip. If there is no RCD, there is still a risk of an electric shock.

ThisIsWeird said:

Won't the still-socketed wire pass through the new cut-out hole? Ie, sideways.

Probably. But it is much easier to skim a wall when there are no sockets/switches getting in the way.

hessodreamy

Yes this will be the plastic box that fixes to the plasterboard, rather than the metal back-box embeded in the wall. I should have been clearer. I'm guessing I'd be fixing the box back to the new plasterboard as the last job ie after painting.

ThisIsWeird

hessodreamy said:

Yes this will be the plastic box that fixes to the plasterboard, rather than the metal back-box embeded in the wall. I should have been clearer. I'm guessing I'd be fixing the box back to the new plasterboard as the last job ie after painting.

Really worth considering 'sinking' the back box, as it's not only much neater when 'flush', but should be more securely fixed too.

As S62 says - do discuss this with your plasterer

stuart45

The sparks normally just tape the wires.

hessodreamy

ThisIsWeird said:

Really worth considering 'sinking' the back box, as it's not only much neater when 'flush', but should be more securely fixed too.

As S62 says - do discuss this with your plasterer

I had no idea that was a thing. I'll definitely be doing that, it looks much neater.

hessodreamy

FreeBear said:

Isolating the circuit in question by flipping the circuit breaker (fuse) will leave the neutral connected - If you have an RCD, as soon as that neutral is touched, the RCD will trip. If there is no RCD, there is still a risk of an electric shock.

Hang on - switching this circuit off at the fuse box still gives you a risk of electrocution? 

Section62

hessodreamy said:

FreeBear said:

Isolating the circuit in question by flipping the circuit breaker (fuse) will leave the neutral connected - If you have an RCD, as soon as that neutral is touched, the RCD will trip. If there is no RCD, there is still a risk of an electric shock.

Hang on - switching this circuit off at the fuse box still gives you a risk of electrocution? 

Yes (if you only turn off the circuit breaker/fuse), because the neutral (and 'earth') wire(s) will still be live.

The 'Main Switch' or whole-house RCD should be double-pole and turning them off should isolate both the brown and blue (red/black) conductors.