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I have a plasterer coming to re-skim my walls in a few weeks and he’s asked me to remove the wall lights and “tape” up the wires.

I can remove the wall lights ok, but just wanted to make sure the wires were safe.

Obviously the electrics will be off when I do this

Do I just wrap insulating tape around each individual wire?

ThreePhaseEel
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User1
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    As long as the right breaker is off and doubled checked, then the wires are safe from giving electric shocks. Tape or wire nuts will keep the wires from scratching skin. Would probably cover the box/es to prevent plaster/paint from getting in, but my opinion. – crip659 Apr 13 '22 at 16:35
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    It's a fail safe, even with a live wire electrical tape will prevent you from getting shocked. With electrical systems the base rule should always be that you only trust what you can determine yourself, and in this case that means the breaker being switched off is a promise (imagine accidentally flipping the wrong breaker), and tape on the ends is a fact. – MiG Apr 13 '22 at 20:07
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    @MiG I agree with this wholeheartedly, despite how many people consider it overcautiousness. If I'm ever going to walk away from an exposed wire it gets taped up. I don't trust myself to not go ADHD and forget what I was doing. The pennies and seconds it takes to tape up wires vs risk of injury or death is easy math. – Logarr Apr 14 '22 at 16:01

7 Answers7

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Having seen the impact that plaster and paint jobs can have on wiring, I'd be more concerned about protecting the wires from the workers!

If the breakers are off and stay off, there won't be any live wires for the workers to touch, so they'll be safe. An added safety measure would be to put a wire nut (or Wago™-style lever-locking terminal, screw terminal, or other common wire connecting/insulating device) on each individual wire (make sure you get a batch of wire nuts of the correct size for the individual wires you'll be capping). This will help protect workers should someone accidentally turn on a breaker.

To protect the wiring and boxes, I'd use some painters tape (or even duck tape) to cover over each box to keep stray plaster out. While plaster in the box isn't a safety item, it can make your life more difficult because you may have to chip the dried plaster out to get wires to move where you need them to. It might clog up the device mounting holes, or there could be enough that devices won't fit in the boxes without having to chip it out.

When you're done, pulling off the tape leaves you with a clean box and clean wires. You won't have to worry about chipping plaster off the already stripped ends of wires, potentially damaging the insulation in the process and needing to cut & restrip wires which could leave you without enough wire to reattach the devices.

FreeMan
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  • Isn't duck tape conductive? – SteveSh Apr 13 '22 at 18:42
  • If it's aluminized, @SteveSh, it might be. Regular, el-cheapo Duck brand tape? I wouldn't think so. I could be wrong. – FreeMan Apr 13 '22 at 20:03
  • Is it safe to tape up the wire and turn the electrics back on and leave it? I’m thinking of removing the lights this weekend but he’s not coming until next week? I don’t think these lights have back boxes and we don’t really use wire nuts in the uk – User1 Apr 13 '22 at 21:26
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    @User1 if the bare ends of the wires are covered with a non-conducting material that won't come off, like Wago connectors, screw terminals, a suitable wrapping of electrical tape, or other code-approved insulating material, you should be fine. Note-If you use multi-port Wagos or screw blocks, DO NOT put more than one wire in each one - you will cause a short that will trip a breaker. – FreeMan Apr 13 '22 at 21:48
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    DUCK is the brand. DUCT tape is the thing. It is Duck brand Duct Tape... https://www.duckbrand.com/products/weatherization/weatherization-tapes/silver-188-in-x-30-yd – Nelson Apr 14 '22 at 07:41
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    @User1 I would go one further than tape. Put the copper wire ends into screw terminals like these https://www.screwfix.com/p/6a-12-terminal-terminal-strips-10-pack/60804, screw down, then tape over the terminal strip. Even if the tape comes off, you cannot get a shock unless you poke something conductive into the terminal strip screw holes. – nigel222 Apr 14 '22 at 09:13
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    @nigel222 - already in my answer below. Cheaper & considerably easier to find in the UK than Wago or wire nuts. You could probably get it in the tiny DIY section they have in supermarkets, not even need a trip to B&Q. – Tetsujin Apr 14 '22 at 09:31
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    I've seen where someone took this a step further and packed the boxes full with plastic grocery bags so it's harder for the painters tape covering it to get ripped off or pushed into the box. It's basically just backing to the tape/filler, so if the plasterer gets rough with the plaster or trowel, the tape doesn't just cave in leaving a box full of plaster. – computercarguy Apr 14 '22 at 18:05
  • Yes, @Nelson, and "duck tape" is also the generic name for "not for use on actual duct-work" tape. Much like "Kleenex" is a genericized brand-name term for tissue (in the US) and "Hoover" is the genericized brand-name for vacuum cleaners (in the UK). TBF, I was not aware that Duck brand sold an actual duct tape - I've only seen other brands at the stores I shop. – FreeMan Apr 14 '22 at 18:09
  • @Tetsujin wilko definitely has, a large Tesco might. – Tim Apr 15 '22 at 12:15
  • @FreeMan: If people may be relying for safety upon a breaker being off, connecting hot and neutral together will prevent the breaker from being switched on for more than 1/50 second. Although deliberately switching on a breaker whose output is shorted isn't safe, since a breaker failure might result in a fire, it may be less dangerous than switching on the circuit and not having anything happen until it is touched by someone who doesn't realize it has become live. – supercat Apr 15 '22 at 17:24
  • Intentionally wiring a short as a "safety feature" seems sketchy at best, @supercat. If you were to post that in an answer, I do believe you'd attract quite a number of down votes, comments telling you (and the world) that it's a bad idea, and possibly get the answer deleted. There was a question a month or two ago about causing a dead short to test a breaker and it was resoundingly thumped as a no-good-very-bad-terrible-day sort of idea. – FreeMan Apr 15 '22 at 17:51
  • @FreeMan: Testing a breaker by flipping it when the output is known to be shorted is a bad idea, but many people who work on high power equipment (e.g. subway tracks) routinely short out the sections upon which they are working, to ensure that there is no way they can become energized by mistake. If e.g. the labels on breakers that controlled two sections of track were swapped, resulting in two workers putting their lock-out/tag-out devices in the wrong places, and worker #1 finished before the worker #2 and tried to turn on worker #2's track, ... – supercat Apr 15 '22 at 18:48
  • @FreeMan: ...the presence of the dead short might fry some equipment, but frying equipment would be less bad than killing worker #2. The purpose of the short isn't to serve as primary protection to ensure that the circuit isn't energized, but rather to ensure nobody gets killed if the primary protection fails. – supercat Apr 15 '22 at 19:04
  • @supercat If you want to create some type of safety, then wire up an alarm of some type. A short is an electrical fault by definition, and you don't setup a fault as a preventative measure. It's like you don't lace your stovetop with gun powder in case there's a kitchen fire and you want to hear an explosion to let you know... – Nelson Apr 16 '22 at 01:50
  • @FreeMan I've seen a sign on a utility truck: "Work it HOT or ground it COLD" (with appropriate colors on the uppercase words.) If putting a dead short on it is proper utility practice I would think it's proper for home use also. – Loren Pechtel Apr 16 '22 at 04:39
  • @Nelson: Installing a dead short in such cases is a bit like installing an automatic derailer on certain places where sidings join the main line. If an errant train is coming onto a siding trying to join the main line, derailing it may not be elegant, but would still be preferable to having it enter the path of a main line train traveling at 100kph or more. – supercat Apr 16 '22 at 04:55
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As the existing answers assume you
a) know what wire nuts are* &
b) have a back box to the light fittings

let me give you a UK perspective…

He wants the light fittings out of his way because he needs to be able to work under where they usually sit. The cables will have to stay in situ & he'll have to work round them.

I don't imagine these light fittings have back boxes, they just fasten to the wall, where there are cables coming out from behind the existing plasterwork, buried in the walls. [Photos could help decide this as an absolute.] If you do have back boxes, tape up the cables & stuff a carrier bag in the box with some extra tape, so the boxes don't get filled with plaster. He'll let you know if he's not happy with that ;)

All he needs is for you to switch off the power at the fuse box/RCD so there is no live mains where he needs to work.
The tape around the wires is for your convenience not his - when he's finished you can take the tape off again & still have clean cables, for when you re-fix the light fittings.

As to whether you tape each individual wire in each cable - that's really a matter of where you put the removed fuse/RCD once the fixtures are out [your pocket is a good place, so there's only you in charge of it for the duration]. If there's any chance, no matter how remote, that someone would possibly think it a good idea to switch the power back on… then tape them individually, then all together. Otherwise just wrap the bundle in tape.

As the OP has mentioned in comments that they want the power back on for a week before the plasterer arrives, then… you're asking for trouble with them just taped. There's a difference between 'technically safe' & 'murphy's law safe' ;) I'd put them in a piece of terminal block & tape that up, just so it can't get knocked.

*You're not expected to have ever seen a wire nut in the UK. We just don't use them.

Tetsujin
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    If I were the plasterer, I wouldn't trust a householder who said that the breaker is off and it's perfectly safe. Adding insulation to the wire ends adds another level of safety. – Simon B Apr 13 '22 at 18:42
  • @SimonB - It's definitely a peace of mind, for sure. I'd want to see the RCD in the guy's hand too ;)) Once the fact is firmly established, though, it then becomes a way to keep the cable ends clean, rather than be of any practical benefit to the plasterer. – Tetsujin Apr 13 '22 at 18:44
  • Yea, you’re right I am in the uk. I haven’t taken the lights off yet. But they don’t look like they’d have back boxes. If I take the lights off today and tape them up is it safe to leave it like that with the power on until he comes back next week? – User1 Apr 13 '22 at 21:20
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    If you want the power back on, then you're asking for trouble with them just taped. There's a difference between 'technically safe' & 'murphy's law safe'. ;) I'd put them in a piece of terminal block & tape that up, just so it can't get knocked. – Tetsujin Apr 14 '22 at 06:17
  • I'd got for terminal blocks and tape as well as turning the breaker off. Even if I'm the only one with access to the breakers I still like to act as if some idiot is going to turn the wrong one on – Chris H Apr 14 '22 at 11:16
  • Taping/screwing them all together would certainly prevent someone turning the power back on, and could act as a sort of self-enforcing promise. Even with a breaker you can get quite a bang from a dead short – Chris H Apr 14 '22 at 11:17
  • @ChrisH - hence the original idea of keeping the RCD in your pocket. – Tetsujin Apr 14 '22 at 11:26
  • @Tetsujin that works too, though once they've been in place for 20+ years they don't always come out very easily. I've never felt the need to physically remove one, just turn it off and tape over the switch. When working on a house, tripping another circuit is a foreseeable occurrence (e.g. from overloading by running everything on extension leads from the one circuit you can keep on) and if that happens you want to be sure the wrong breaker isn't reset. – Chris H Apr 14 '22 at 11:31
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    Also: if you have more than one set of wires going to a single hole in the wall, label them before you disconnect them. You'll thank yourself later. – bta Apr 14 '22 at 18:55
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The plasterer is looking for you to remove the cover plates, and then put a protective cover over the junction box so that mud and paint doesn't get in there.

We see it all the time where this task has been neglected, and the box is full of gray lava, and the wires are all white. That is an electrical code violation that must be corrected, at some cost.

In other words, the plasterer is telling you "I won't be responsible to do that job".

Harper - Reinstate Monica
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Assuming the power is off (a contact-less power detector can be useful here), just cap the hot and neutral with wire nuts.

You can add electrical tape, but the wire nut (assuming a decent tug doesn't pull it off) should suffice for protecting them against grabbing a live wire.

Machavity
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    If the breaker is off, there won't be any live wires for them to grab! – FreeMan Apr 13 '22 at 17:00
  • I would use a wire nut but tape should be fine, if like most that circuit will be needed once insulated and stuffed into the box the power can be turned back on. I would not cover as this may make a bump or ridge at the box. – Ed Beal Apr 13 '22 at 17:17
  • @FreeMan A wire is hot unless you have personally verified otherwise. – Loren Pechtel Apr 16 '22 at 04:41
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Last time I did this I isolated the circuits ( by removing the wire from the breaker as well as pulling the neutral).

Then I used short bits of plastic tube to cover the insulated wires so that the extra plaster and paint etc did not « gum » up the wires etc. Made it much easier to see later.

Solar Mike
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Turn the breaker off. I never trust a breaker that is "off" and not locked or out of site. I would simply get the camera out and take pictures. Identify the wires with color tape or wire numbers (I use the latter) and take another picture with the identification showing. Then remove the fixture and wire nut the wires so no conductor is showing. If there are other wires in the box let them be. Push the wires back in the box then use news paper or something similar and pack the box full wires fully covered. Turn the breaker back on. After painting etc when you put the lights back, turn the breaker off and get out your pictures. Remove the newspaper from the box, should be easy. Install the fixture (new or old) and mount the fixture. Turn the breaker on and you should be all set

Gil
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Belt and braces - and a piece of string!

1st turn off the appropriate switches/breakers.

2nd put insulating tape over those switches - red is good - to remind anyone that they're supposed to be like that.

3rd cover all the bare wire ends (separately!) with insulating tape.

4th put a plastic bag over each outlet,(and wires), secured tidily with more tape, or better, masking tape.

Tim
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