Lighting (no, not that sort) and wiring

mjr

Comfy armchair to one person & a plank to the next
There's a lot more people here who are far more experienced with tools and wiring and stuff than I am, so I throw myself onto your advice.

I think there's a fault on the lighting wiring in between the ceiling and the floor. One of the inset spotlights is flickering and when I remove the bulb and hood, I can see what looks like a damaged wire, possibly from the previous owner failing to install the heatproof hood correctly (I wasn't happy when I found that a few years ago). The floorboard above is large 6ftx3ft boards nailed down (I was hoping it was screwed down). Would you try to do it as a sort of keyhole surgery through the spotlight hole (hoping there's enough slack in the cable to pull the damaged section out and possibly splice), try to lift the floorboard with a huge crowbar or by chipping around the nail heads to get a claw hammer in, cut an access panel into the floor, or surrender and call in an electrician? (And will the electrician offer me the same choice between lifting boards and cutting an access?) Thanks in advance for any opinions.
 
Location
Kent Coast
Having nearly electrocuted myself once whilst doing a "simple" job on my house, I would vote for getting a professional in.
 
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mjr

mjr

Comfy armchair to one person & a plank to the next
Having nearly electrocuted myself once whilst doing a "simple" job on my house, I would vote for getting a professional in.
I probably should have said: I've done simple wiring jobs before (although only really trivial stuff like socket replacement in this house so far IIRC) and I have the clamp-on kit to test for power in a cable before I touch it. Last time I zapped myself was (many years ago) plugging a doorbell in :wacko:
 
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mjr

mjr

Comfy armchair to one person & a plank to the next
[QUOTE 4603297, member: 9609"]what sort of bulb is it - the 50w halogens got very hot and the tails would eventually start to break up. Is there a little transformer up there, sometimes the whole lot can be pulled down through the hole.[/QUOTE]
5w LED now. I replaced a 35w halogen some time ago (along with many many others - the lighting in this house consumed a silly amount when I moved in) which is when I discovered the semi-detached hood and I suspect it's the heat from that which damaged the wire I can see, which looks like they usual flat 3-core electrical cable like I've seen connecting lights under upstairs floorboard before. I'll shove a periscope up the hole and see if I can spot a transformer and anything else about the wiring.
 

GrumpyGregry

Here for rides.
5w LED now. I replaced a 35w halogen some time ago (along with many many others - the lighting in this house consumed a silly amount when I moved in) which is when I discovered the semi-detached hood and I suspect it's the heat from that which damaged the wire I can see, which looks like they usual flat 3-core electrical cable like I've seen connecting lights under upstairs floorboard before. I'll shove a periscope up the hole and see if I can spot a transformer and anything else about the wiring.
you'll know by the voltage of the bulb surely? Mains or 12v
 

GGJ

Veteran
Location
Scotland
Jigsaw a hole in the floor large enough to do the repair, then screw 4 wooden fillets to the edge of the hole and replace the cutout section with a few more screws
 
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mjr

mjr

Comfy armchair to one person & a plank to the next
you'll know by the voltage of the bulb surely? Mains or 12v
Mains.

Now I'm back, I had another look. The damaged cable is thinner than I thought and runs from a black box (that I think the bulb holder is also connected to) and off towards another spotlight. The black box is stuck somehow to the upper side of the ceiling panel. There doesn't seem to be enough slack in the cable to pull it through the hole - I guess if there was enough slack, a cable between spotlights wouldn't have been routed directly over one of them :wacko:
 

screenman

Legendary Member
I would try from below and the cut along the joists upstairs and across the void to lift out a foot wide piece of floor board. The nails, I use a hole borer on these normally a 10mm one and easily lift the board and remove nails later. I have showed this trick to a few sparkies and plumbers and they have been amazed how easy and quick it is. I run a circular saw along the joins above the joist and across.
 

cosmicbike

Perhaps This One.....
Moderator
Location
Egham
I would try from below and the cut along the joists upstairs and across the void to lift out a foot wide piece of floor board. The nails, I use a hole borer on these normally a 10mm one and easily lift the board and remove nails later. I have showed this trick to a few sparkies and plumbers and they have been amazed how easy and quick it is. I run a circular saw along the joins above the joist and across.
Love that tip, doing a house ATM with ply sheet flooring and been drilling the nail heads off. I use a multimodal to cut the tongues off though.
 
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mjr

mjr

Comfy armchair to one person & a plank to the next
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mjr

mjr

Comfy armchair to one person & a plank to the next
That's probably a junction box and is where you would remove the old bit of cable and connect the new.
Yeah, that's my guess too. It's aligned with the bulb holder and damaged wire on one end, so I can't see for sure what else is on the other side of it... I'll guess it's the supply cable but it doesn't really matter because if I need to crack it open the floor to put new cable in, I'll see then.
 

twentysix by twentyfive

Clinging on tightly
Location
Over the Hill
Yeah, that's my guess too. It's aligned with the bulb holder and damaged wire on one end, so I can't see for sure what else is on the other side of it... I'll guess it's the supply cable but it doesn't really matter because if I need to crack it open the floor to put new cable in, I'll see then.
When you do turn the supply off at the consumer unit (only need to switch off the circuit breaker to that lighting circuit). I'd never ever work on mains without it being off!
 
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