Fire rated GU10 fittings and Rigid Roof Insulation in attic ceiling?

MiketheMechanic

Hi folks,

I want to use GU10 fittings in the locations indicated by the blue circles in the attached photo.

I plan to use Philips 6W dimmable LED GU10s. (But someone could in theory put 50w halogen GU10s in these fittings some day, down the road)

Should I use an enclosed Fire rated GU/GZ10 fitting like a Robus RF201?

Can these fittings simply be cut into the rigid insulation.

I am using 50mm Xtratherm rigid between the rafters as shown, with a 72mm insluated slab over it.


If I go with the enclosed fire-rated fiting, do I need the insulation caps for air tightness and fire safety?
(would I even have the space/depth for these on the 45 degree pitch part of the ceiling?)

Hopefully one of you has encountered this before and can advise.

Thanks in advance.

tomdempsey200

http://www.ledgrouprobus.com/catalogue/l3/product?item_id=RFS1016545WW-01

what are the bathroom fittings like for air-tightness?

the regular fire-rated wouldn't be air-tight anyhow

2011

MiketheMechanic wrote: »

I plan to use Philips 6W dimmable LED GU10s. (But someone could in theory put 50w halogen GU10s in these fittings some day, down the road)

Yes, although LEDs generate little or no heat a halogen lamp will so it will need some breathing space.

Should I use an enclosed Fire rated GU/GZ10 fitting like a Robus RF201?

You could, but these can not tilt and your plan is to use them on an angled ceiling. I assume that you want to be able to angle them straight down?

Can these fittings simply be cut into the rigid insulation.

I would think so, but it is always best to read and follow the manufacturer’s instructions (that way you know you are covered).

If I go with the enclosed fire-rated fitting, do I need the insulation caps for air tightness and fire safety?

Insulation caps would be great form an air tightness & insulation point of view but as above it is always best to read and follow the manufacturer’s instructions (that way you know you are covered).

(would I even have the space/depth for these on the 45 degree pitch part of the ceiling?)

I would think so.

If it was my home I would install standard tilt downlighters with dimmable LED lamps and insulate around the fittings. If I was concerned that someone may install halogen lamps in the future I would put discreet warning stickers on the fittings (that would only be seen during lamp replacement) stating something like "Only suitable for LED lamps. Incandescent lamps may cause fire hazard!"

MiketheMechanic

Thanks folks,

Could I use something like this?

http://www.adverts.ie/fixtures-fittings/robus-gu10-fire-acoustic-rated-downlight-directional-brushed-chrome-rf208-13/1595177

I'm still confused as to how I could get an insulation cap in behind one of these fittings when it is on a roof ceiling.

I just worried that 6 or 8 of these will allow a lot of cold air down into the room. What's the best way to prevent this?

Thanks,
MtM

2011 wrote: »

Yes, although LEDs generate little or no heat a halogen lamp will so it will need some breathing space.



You could, but these can not tilt and your plan is to use them on an angled ceiling. I assume that you want to be able to angle them straight down?


I would think so, but it is always best to read and follow the manufacturer’s instructions (that way you know you are covered).


Insulation caps would be great form an air tightness & insulation point of view but as above it is always best to read and follow the manufacturer’s instructions (that way you know you are covered).


I would think so.

If it was my home I would install standard tilt downlighters with dimmable LED lamps and insulate around the fittings. If I was concerned that someone may install halogen lamps in the future I would put discreet warning stickers on the fittings (that would only be seen during lamp replacement) stating something like "Only suitable for LED lamps. Incandescent lamps may cause fire hazard!"

2011

MiketheMechanic wrote: »

Thanks folks,

Could I use something like this?

http://www.adverts.ie/fixtures-fittings/robus-gu10-fire-acoustic-rated-downlight-directional-brushed-chrome-rf208-13/1595177

They look good to me.

I'm still confused as to how I could get an insulation cap in behind one of these fittings when it is on a roof ceiling.

This is an easy situation to deal with now because the ceiling is not slabbed.
I have seen people build boxes out of fire proof plasterboard. These boxes house the downlighters and are 100% sealed with insulation packed around the outside.

tomdempsey200

it's tricky enough by the look of it to get air-tightness from behind with xtratherm and insulated slab .

if you built something into the xtratherm you'd nearly have to apply a layer of silicone around it before slabbing to eliminate air-gaps


i would have though myself the bathroom spot would be a good starting point...i'm not sure how important tilt would be


i wouldn't consider spots myself without a decent air-tightness solution..too much spent on insulation to lose it on draughts
my first preference would be a surface solution here

tomdempsey200

if you fitted something like that flush actually into the xtratherm as your air-tight housing rather than sitting on top of the xtratherm

you'd still have to ensure there was no air gap between xtratherm and slab using silicone or whatever

Stoner

you can get light fittings that you can insulate right up to but they can only supply certain wattage fittings, I've seen some with 11 W and 35 Watt max ratings,

Up inside the fitting when you remove the lamp there is a warning sticker stating "do not use lamps rates at over 11 Watts" this allows you to use them as far as I'm concerned as it is sufficient warning not to use a 50 watt lamp in them


I have these fitting in my house, I have 50 mm Xtratherm rigid and above that 150 mm of rock wool insulation, I have the insulation around the fittings, the fittings itself even has a small amount of insulation in its walls.

I looked them up recently and the rating has increased from 11 to 35 Watts, but I'd never use a 35 Watt lamp in them.

they are very good compared to open back fittings, when cold they are still a cold spot on the ceiling and show up poorly on a thermal heat gun, however they seem to contain the cold spot to the diameter of the fitting.

I have one standard open back fitting in the arrangement, it one of those jobs I have yet to get back to over the past two years, but the radius of the cold spot from this fittings is greater than the insulated fitting by a significant degree.

also as a note the Aurora fittings have deeps springs to allow them to grip the 50mm rigid material

Mr.Fred

Personally I wouldn't be bothered with the lights down the side. Increase the number down the middle and you'll have more than enough light, maybe one over the stairs.

you could wire in 5A skts for bedside lamps etc.

MiketheMechanic

Thanks everyone.

Stoner, where would I find the Aurora fittings you mentioned? Would you have a link?

I picked up a Robus RFS10165GZ fitting today - its an enclosed fire rated shower downlight. They are also available without the frosted shower cap for a regular room. With a 6W lamp, the can fit prettly tight against the rigid insulation. I like the idea of a warning on the inside advising not to use a high wattage halogen GU10. The open back GU10 seems to be a no-no from a heat loss point of view.

Stoner wrote: »

you can get light fittings that you can insulate right up to but they can only supply certain wattage fittings, I've seen some with 11 W and 35 Watt max ratings,

Up inside the fitting when you remove the lamp there is a warning sticker stating "do not use lamps rates at over 11 Watts" this allows you to use them as far as I'm concerned as it is sufficient warning not to use a 50 watt lamp in them


I have these fitting in my house, I have 50 mm Xtratherm rigid and above that 150 mm of rock wool insulation, I have the insulation around the fittings, the fittings itself even has a small amount of insulation in its walls.

I looked them up recently and the rating has increased from 11 to 35 Watts, but I'd never use a 35 Watt lamp in them.

they are very good compared to open back fittings, when cold they are still a cold spot on the ceiling and show up poorly on a thermal heat gun, however they seem to contain the cold spot to the diameter of the fitting.

I have one standard open back fitting in the arrangement, it one of those jobs I have yet to get back to over the past two years, but the radius of the cold spot from this fittings is greater than the insulated fitting by a significant degree.

also as a note the Aurora fittings have deeps springs to allow them to grip the 50mm rigid material

Stoner

Mike,

I cant remember the exact code, they have changed since i think, but it will be one of these
http://gb.auroralighting.com/Products/Indoor-Luminaires/Fire-Rated-Downlighting.aspx

I got mine in edmundsons for about 25 each, but they have come down a lot since, I'm sure most wholesalers will get them for you.

You'll find them online

At that cost a wholesaler with a guarantee might be a better option.

Edit
something like this allows " Integrated heat sink allows downlights to be covered with thermal insulation. Downlight insulation guard not required"

http://gb.auroralighting.com/Products/Indoor-Luminaires/Fire-Rated-Downlighting/GU10-Fire-Rated-Downlights/240V-GU10-Aluminium-IP65-10W-Insulation-Covered-Lo.aspx


read the specs, should have what you want, you just need an empty one to take a GU10 lamp.

note on the pic how deep up the fitting the spring is fixed, this will suit the 50mm insulation

indie armada

Aurora are based in Northpark ind est in finglas.
They do not deal directly with the public but they do have a showroom.
ph 8914022.