Downlighters - flat roof

[Coogie]

OK, maybe i'm reading into too much on the web, but i'm getting confused.

Can i fit mains halogen downlighters under a flat roof (no rooms above) with 8" joists? I intend to use 4" Kingspan insulation, and was intending to cut a hole in the insulation about the size of a dinner plate to give the light free space

Is there a serious fire risk in doing this, or do i need a fire hood etc etc?

Any advise or other considerations would be well appreciated

Thanks

 

[Chri5]

The lights can run very hot, so your kingspan will have to be a decent distance away from the fittings.

Hoods won't be required- since they tend to be used when the lights are between occupied floors, more so when it's a different occupier at each level.

Could you not go cool running LED or low energy ?

As a safety if you have to go GU10's then I'd suggest the complete housing type

Fire Rated ( 100 Minutes ) and Acoustic Compliant Downlighters
50w GU10 Downlight - Chrome, via TLC: FR DG 10C

 

[Lectrician]

I had the same dilema in my own home.

I opted for a centre light!

I did not want to cut holes in the celotex to accomodate the lights. The celotex is there for a reason after all.

 

[Coogie]

How far is a 'decent distance'?

Its the heat / fire element that concerns me the most. I hadnt considered LED - do they require a transformer to run?

If i were also to fit in a ceiling where i did have a room above - would i need hoods then?

I prefer the look of down lights, but there're sounding more complex???

 

[Taylortwocities]

The manufacturer's instructions will say what the clearances are.

You should leave at least that much. The lights will be running in enclosed space and the hotter it is then the shorter life you'll get from the lamps.

You do not need fire-rated fittings even if there is a room above unless the ceiling is acting as a fire-break. In most houses they are not unless its the garage roof.

There's a misconception over fire-rated halogen light fittings. They are not put there to stop the light fitting catching fire. They are there to slow the progress of fire if a fire starts in the room in which the fittings are placed.

 

[GaryMo]

If you select fittings with the symbol below then they're suitable for mounting in/on normally flammable surfaces where a thermal insulating material may cover them.

Untitled

• GaryMo
• 26 Aug 2008
• 1

 

[ban-all-sheds]

There's a misconception over fire-rated halogen light fittings. They are not put there to stop the light fitting catching fire. They are there to slow the progress of fire if a fire starts in the room in which the fittings are placed.

And here's a very timely example of why this is a potentially fatal misconception:

http://www.ebuild.co.uk/forums/messages/770/19134.html?1219778384

If you start out thinking that firehoods are needed because of the heat from the lights then the flipside of fitting them when not needed (or being told to fit them by ignorant BCOs) is not fitting them when they are needed if you're installing LED luminaires in a fire compartment ceiling....

 

[Taylortwocities]

Ooh BAS, you are so... omnipresent, aren't you

 

[Pensdown]

I wonder what his total post count would be across all fora.

 

[333rocky333]

I hadnt considered LED - do they require a transformer to run?

you can get LED lamps that fit the same as GU 10 lamps and run on mains voltage.

or
you can get LED fittings that need a LED Driver, these are similar in size to a transformer but only work with LED type lamps

 

[Coogie]

Would this suit?



http://cgi.ebay.co.uk/10-x-FIXED-24...39:1|66:2|65:12|240:1318&_trksid=p3286.c0.m14

 

[P.S.]

to match the brightness of a halogen 50w GU10, you'll need a decent 3watt or above luxeon (or equivalent) LED. These can be upwards of £25 each. A good alternative to these are the compact fluorescent gu10's. However, the CFL and some LED's are longer than a standatd gu10 bulb so unless you use open back down-lighters, you'll need to make sure that any enclosed fittings will take the extra length (oooh errr)

examples :

LED: http://www.ultraleds.co.uk/u10n3wwgu10-240v-watt-nichia-warm-white-leds-wide-angle-p-1579.html

CFL: http://www.tlc-direct.co.uk/Products/GUCFL11.html (also come on lower wattage and dimmable)

I have 14 GU10 downlighters on the kitchen extension, and have to replace 12 MR16 in the original kitchen with GU10's. LEDS were my first choice but the expense was a limiting factor (£520 just on bulbs !!!)

Also you have to account for the colour temperature of the bulb. For the kitchen I wanted a bright white, and althought the above CFls state "warm white" they are actually whiter than than I had expected. picture to follow

 

[P.S.]

as an example, the two pin-pricks of light in the middle are LED Luxeon's (think they are 3watt but will check) they do throw off more light that it appears in the picture to be fair. the rest are the 11watt cfls (2700K)

(what appears to be a bulb out top right, is one of three PIR's so that you never need to switch on or off the lights - handy for a kitchen.

one slight downside with the CFl's is, switched on from cold, they start out pink and take a few seconds to get to full white brightness. But this is handy if doing a midnight fridge raid and you don't get blinded

 

[Coogie]

Thanks - but the picture didnt seem to come through?

I also found these, would they be sufficient?

http://www.thelightingsuperstore.co.uk/product.asp?productid=18114

They are 7W - would this lead to a big reduction in light?

I assume that the low energy lights run cooler too?, and how many would you suggest in a 10' x 12' room?

Thanks again.....

 

[P.S.]

Thanks - but the picture didnt seem to come through?

try now (used someones photobucket id)

I also found these, would they be sufficient?

They are 7W - would this lead to a big reduction in light?

I assume that the low energy lights run cooler too?, and how many would you suggest in a 10' x 12' room?

Yes they run MUCH cooler. What type of room is it, dining, living, kitchen, bedroom ?