Downlights in flat

[antgel]

I live in a purpose-built block of flats with concrete between floors. I'd like to install low-voltage downlights without separate transformers. As I have no access from above, I'm a bit unsure how to proceed.

I asked the bloke in B&Q who said that it should be possible, having drilled the holes, to poke a length of stiff wire through one and out of the other. I could then tie a bit of ring flex to the end and pull it through. I can see this as being difficult at best. Anyone done it / knows if it's doable?

The other problem I will face is joists. I can go round with the detector to locate them. I assume that if they are in "bad" locations then the above method will fail.

So just in case, what's the biggest hole that I can butcher into my celing that will be fixable by a competent plasterer? (cough) There is another reason for asking. I have a projector which I want to celing mount, and have the cables run via the celing and down the front wall of the lounge, to the sky and dvd boxes etc. I could theoretically run these in the same way.

Having just knocked down the wall between my kitchen and lounge, I have many more questions (such as why oh why), but I'll put them in separate threads. :)

Antony

[John Rumm]

Did it the other day... so "yes" is the answer. However there are some things you need to check out first.

Do you have enough space above your ceiling? You will need at least 4" of depth, but 6" would be better. This is not only to allow height for the rear of the light fitting but also to help dissipate the heat.

Note that there are extra rules on fire breaks between floors of multi-storey and multi occupancy buildings that do not always apply to private dwellings. Hence you need to be sure that the plasterboard on the ceiling is not a part of the fire defence before you go making big holes in it! (you can still do it if required - but you would need intumescent hoods over the back of each light fitting.

Don't worry about transformers particularly. Most lights will need at least 80mm of cut-out in the ceiling, which is usually plenty to poke a transformer through if needed.

It will fail unless you take other steps - i.e. to drill through the joist sides (can be done with a very long drill at a angle through the hole you have cut for a light), this requires an access hole for each joist however - not good if you have the bad luck to need to cross 10 of them and only wanted one light! ;-) The other solution is to chop out a small section of plasterboard under the joist and then drill a series of shallow holes into the base of the joist with a wide spade bit - creating a channel that you can feed a wire through. You would then need to replace the ceiling (preferably with some capping under the wire to protect it since it will be close to the surface in a non obvious place otherwise)

Well any size hole can be patched - it would be better to do the job without needing excess holes though.

Given the cables may have large plugs on them, this makes the job much harder if you need to go across the joists. If that were the case, it would be worth removing the plug and re-fitting after it is in place. Run spare cables to cover all eventualities as well (i.e. if the projector has SVGA and component inputs, cable both - even if you only plan to use one. That way you keep your options open.

[adder1969]

floors.

First question is do you *really* want halogen downlighters? I installed some and ripped them out shortly afterwards! I prefer uplit spaces to downlit ones.

The coathanger thing works provided as you say there are no battens in the way.

You could rip down all the existing plasterboard, lay whatever cables you want then put a new ceiling up.

I don't know if it contravenes the regs but you could also run the wires in the corner of the wall/ceiling and cover over with coving.

If you're fitting more than one set, remember that you'll need to run LV and HV cables of the correct size.

[Antony Gelberg]

A quick poke with a screwdriver indicates a mere 2" before I hit concrete, so looks like all bets are off. I don't want a false ceiling as the current one is only about 7'6" high. Looks like I'm shopping for some normal light fittings, but even this could be difficult as I want them to be relatively shallow and I haven't seen much that I like.

Probably a blessing in disguise, going by some of the comments.

Antony

[adder1969]

ceiling

There are plenty of shallow lights on the market at the moment - the ones that look like spots but they're not or the flush mounted dome type.