Installing spotlights in ceiling without access from above

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sammy.se
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Installing spotlights in ceiling without access from above

Post by sammy.se »

Hi All,

I'm looking to add some ceiling downlights in my downstairs dining room and kitchen. However, the challenge is that the room above is a bathroom which is tiled, and a small area of carpeted landing.
Therefore, I will be able to see a little bit of the joists / ceiling from above, but I will mostly need to run the wires and work from underneath the ceiling.

Before I cut out a hundred holes in the ceiling to try and achieve this, do you have any tips on how I can do this? and any tools you recommend?
the ceiling is typical Victorian structure: 6x2 joists, with plasterboard in some areas and lathe/plaster in others.
I'm looking to run two rows of 4 lights (so 8 lights in total).

I have installed spotlights before, but have always had access from above. Thanks!!
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Installing spotlights in ceiling without access from above

Post by banjerbill »

It's not too difficult if the cable run goes in line with the joists. It's a pig of a job if the joists are at right angles to the run.

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Installing spotlights in ceiling without access from above

Post by sammy.se »

Thanks Bill - If going across joists (if they are at right angles) I assume I have to cut a hole in the ceiling next to each joist, to drill a hole for the cable?
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Installing spotlights in ceiling without access from above

Post by banjerbill »

Yes but you would probably get away with one opening per joist and use a fish to feed the cable to the next opening. Not an easy task but doable. Of course you won't be going through all the joists, how many is governed by your light placement. The other option is a false ceiling, a major and expensive undertaking.
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Installing spotlights in ceiling without access from above

Post by arco_iris »

banjerbill wrote: Fri Jan 15, 2021 6:10 pm Yes but you would probably get away with one opening per joist and use a fish to feed the cable to the next opening. Not an easy task but doable.
If they are low voltage or LED spotlights, you'll be able to use much thinner cable, e.g. like speaker wire (check the installation instructions).
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Installing spotlights in ceiling without access from above

Post by Someone-Else »

arco_iris wrote: Fri Jan 15, 2021 6:26 pmIf they are low voltage or LED spotlights, you'll be able to use much thinner cable,
Not a good idea as you then have volt drop and a power supply to take into consideration, no such problem if the lamps are mains powered.
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Installing spotlights in ceiling without access from above

Post by ericmark »

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This may be the way forward, don't try hiding wires, make them a feature. It would need to be extra low voltage and so would require a toroidal transformer, not an electronic one as LED lamps don't like electronic transformers.

There is lighting track, and lighting bars, with lighting track Image you can use low voltage (230 volt) so no transformers.
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Installing spotlights in ceiling without access from above

Post by sammy.se »

Thanks all for the advice.
I think that if I go to the trouble of feeding cable, I'll feed 1.5mm, even though I plan on using LED bulbs.

I will check out the track system though, might be a good alternative!
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Installing spotlights in ceiling without access from above

Post by sammy.se »

Oh, another question, do I need to worry about insulation and the lighting wires?
The spot lights themselves won't have any insulation around the (I'll clear a space), but there might be 100mm rockwool in the ceiling cavity where the cables will run.
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Installing spotlights in ceiling without access from above

Post by OnlyMe »

If you use 1.5mmT&E then you need not worry about insulation around the cable.
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