Schoolboy error

[Ivor the Engine]

I have a doubled skin ceiling of 10mm acoustic plasterboard with resilient bars of approx 16mm depth running between. The total height from the ceiling face to the acoustic mineral wool is 130mm.

As standard flush mounted lights need 150mm how can I get round this? To compound my misery I have not cut away any plasterboard from either of the ceilings, nor left any gaps in the mineral wool. I am presuming I would need to cut this away from the hole I cut for the light to eventually sit in.

I have made a total balls up, but am hopeful that someone may have a solution. Any ideas?

[gareththomas01]

Firstly you can get spacers so you can sit these off of the ceiling

Secondly to cut the holes I would use a suitable holesaw.

Thirdly, as a qualified electricien you need more air-space to avoid overheating especially as you are using wool. Everything will be fine until your wife gets that self-tanning system she always wanted...

Gareth

P.S. you need to put little 'top-hats' over the top of your downlights. These are like witches hats that resist/contain fire.

[hornydragon]

I would look at some of the new LED based downlights as these run alot cooler than halogen, should be shallower too. (what is the existing lighting?) LED's are more sxpensive but only need 25-50mm depth depending on style
Example http://www.mr-resistor.co.uk/item.as...2&r=243&i=2477

[Ivor the Engine]

Thanks for the responses. The room is a basement conversion, so there is no existing lighting. Any pointers to where I can get spacers from would be a blessing. I had some thoughts about using LED, but it looks like my hand might be forced as I need a fairly quick fix.

Cymru am byth.

[hornydragon]

Originally Posted by Ivor the Engine

Thanks for the responses. The room is a basement conversion, so there is no existing lighting. Any pointers to where I can get spacers from would be a blessing. I had some thoughts about using LED, but it looks like my hand might be forced as I need a fairly quick fix.

Cymru am byth.

Erm so you fitted the ceilings with no lighting cabling at all?

[Ivor the Engine]

Not quite that stupid I neglected to cut any reasonable size hole in the first ceiling and neglected to leave gaps in the mineral wool. I have enough cable for ten down lights on two seperate mains.

I should have sourced lights beforehand, but we learn by our mistakes as Plato would have it.

Would like to install traditional downlighters, but the practicality of cutting away is not ideal, unless there is an ingenious solution.

ATB

[hornydragon]

well, mostdown light installs require the ciling to be cut and cable threaded between them I think LED may be the way forward (depending on USE) you can get surface mount units as well as tracks but cutting holes and threading is pretty standard!

[neilball]

Originally Posted by Ivor the Engine

Not quite that stupid I neglected to cut any reasonable size hole in the first ceiling and neglected to leave gaps in the mineral wool. I have enough cable for ten down lights on two seperate mains.

I should have sourced lights beforehand, but we learn by our mistakes as Plato would have it.

Would like to install traditional downlighters, but the practicality of cutting away is not ideal, unless there is an ingenious solution.

ATB

Well a traditional downlighter fitted (with an aluminium coated lamp if neccessary) should easily be accomodated within a depth of 130mm. See here and here for some specs, both quote recess depths of 110mm.

Fire-rated downlighters are more of a problem as they generally quote 140mm recess depths. Note that the depths quoted include 25mm clearance between the terminal connections on the top of the lamp and the structure above. However you may be able to trim 10mm from the mineral wool through the cutout using long-nosed pliers or similar to give you the clearance you need if you want to go for fire/acoustic rated downlighters.

Cutting out is easy if you have the appropriate sized hole saw and have not made the hole where the cable pops out too large. Otherwise a decent pad saw makes easy work of cutting the holes, simply mark the ceiling first and take it slowly and you will get a good, clean hole for the downlighter to fit into. Just make sure the fitting is not a tight fit into the hole as this will damage the ceiling when you try and remove it next time.

[Ivor the Engine]

Many thanks for the info. I phoned Screwfix and they promised to phone me back and never did. The question I was going to put to them was about clearnces funnily enough.

I'm going to have to go for fire rated as I need the room signed of by builidng control.

Your confidence in this being a solvable problem is gratefully appreciated.

ATB

[neilball]

Well I reckon a fire-rated fitting will physically fit right now although the clearance for the cable connection will only be 15mm rather than the 25mm quoted on the spec sheets. I used Aurora fittings throughout my new build and found that the support for the cable connector has some play in it in any case so I doubt you will have any problems