downlights inbetween RSJ beams

[lidster]

I am thinking of putting 2 downlights http://www.toolstation.com/shop/Lig...djustable Downlighter MR16/d220/sd2721/p60853

in between 2 RSJ's I have recently had installed after knocking down a chimney breast. Ive read up on here a bit about spacing between wooden joists, and the fire hazards - but not RSJ's.......
The 2 RSJ's are "I" shaped and bolted together but there is a gap in between them which I think may fit these lights. They are encased in double plasterboard for fire regs. above one is the brick wall above, and above the other is the bricks for the chimney breast above and to the best of my knowledge there is no wood around where I want them fitting. I will try and find a picture of when the work was being done to explain it a bit better.
Anyway - its a tight fit to get them in, but I reckon there is about 200mm cavity at least in the middle of the 2 RSJ's - and the surrounding area should be bricks/cement and metal only.
Does anybody see any fire/safety problems with this idea?

 

[lidster]

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[riveralt]

Follow the manufacturers instructions regarding the distance between the lamp and the obstruction. The distance is normally required to ensure the lamp unit itself has sufficient air to operate correctly. I would suspect that your RSJ location would not meet this criteria.

Alternatively, contact the manufacturers of the lamp and ask them about your proposal.

As this is a 12v lamp unit don't forget that some transformers have specific space and cable distance requirements as well.

 

[RF Lighting]

Also you're going to require 90 minute fire rated fittings if you're penetrating double plasterboard.

As much of a fan as I am of downlighters, I'd really advise you against fitting them here.

 

[tew1]

It's ok for the recessed light casing to touch the RSJ's, with timber joists they would cause charring with the heat. You have to choose 1/2 hour fire-rated downlights like the ones from toolstation (which come with a metal recessed cylinder)

 

[riveralt]

It's ok for the recessed light casing to touch the RSJ's, with timber joists they would cause charring with the heat. You have to choose 1/2 hour fire-rated downlights like the ones from toolstation (which come with a metal recessed cylinder)

How do you know that without consulting the manufacturers instructions?
A random pick of one set of FR downlights for example requires space of nearly 300mm for the manufacturers instructions to be met.

The need for space around the down lighters is two fold - firstly to prevent combustion but also to allow the lighting units to keep cool - I don't believe placing right next to an metal RSJ will achieve this.

 

[tew1]

It's ok for the recessed light casing to touch the RSJ's, with timber joists they would cause charring with the heat. You have to choose 1/2 hour fire-rated downlights like the ones from toolstation (which come with a metal recessed cylinder)

How do you know that without consulting the manufacturers instructions?
A random pick of one set of FR downlights for example requires space of nearly 300mm for the manufacturers instructions to be met.

The need for space around the down lighters is two fold - firstly to prevent combustion but also to allow the lighting units to keep cool - I don't believe placing right next to an metal RSJ will achieve this.

I did this in my own home. It's obvious really. A huge metal RSJ will very quickly dissipate the heat from a halogen downlight. What do you think's going to happen to it? It's not going to catch fire lol. The space requirement is for usual circumstances where it could be in close proximity to flammable surfaces. All fire rated recessed lights like this one from tool station are basically exactly the same (a metal can to house the bulb). There is plenty of airspace for cooling in the gap along the entire length of the RSJ (and the whole cavity wall above it). If it's double plasterboard (I'm guessing 12mm?) you need to go for the 90 min fire rated lights (not 1/2 hour then). You can get purpose-made metal boxes to go over downlights for when installing insulation above them (e.g. lofts) so it's no different

 

[RF Lighting]

Yeah I'd take your guess work over the manufacturers instructions to guarantee the safety of my home any day

 

[tew1]

Yeah I'd take your guess work over the manufacturers instructions to guarantee the safety of my home any day

it's just common sense really. How would it be any different to putting one of these over it? http://www.screwfix.com/p/halolite-...tracking url&gclid=CNHpsd7A0LgCFSTKtAodPEwAzw

 

[RF Lighting]

You still need to leave the manufacturers specified clearances between the light and the insulation box.

 

[tew1]

Untitled

• tew1
• 27 Jul 2013
• 1

I have about a half dozen like this in my kitchen, its been that way for 5 years

 

[RF Lighting]

Good for you.

 

[lidster]

thanks for replies, been on holiday and then forgot to reply!

Untitled

• tew1
• 27 Jul 2013
• 1

I have about a half dozen like this in my kitchen, its been that way for 5 years

That picture is identical to what I want to achieve.... ~I have bought 1 of these lights now to check instructions and they are rated 90 mins. still not fitted them or tried to cut out the double plasterboard yet, but from the looks of them they will fit up between the 2 RSJ's.

As for the manufacturers instructions.... the only reference made to minimum distances is this
"Ensure there is adequate free air ventilation around fitting. Minimum distance from the lighting object 0.50 meters. Do not install this product into new plaster or damp areas"

Is that a typo? Im struggling to think of a situation where these lights could actually be used where there is no objects within .5 meters...

 

[JohnW2]

"Ensure there is adequate free air ventilation around fitting. Minimum distance from the lighting object 0.50 meters. Do not install this product into new plaster or damp areas"
Is that a typo? Im struggling to think of a situation where these lights could actually be used where there is no objects within .5 meters...

I would imagine that the 0.5 metres probably refers to the minimum distance an object should be in front of the lamp (i,e, with the light shining onto it).

Kind Regards, John

 

[lidster]

I would imagine that the 0.5 metres probably refers to the minimum distance an object should be in front of the lamp (i,e, with the light shining onto it).

Ha - yes of course that makes sense- just found a little icon/pic showing that ....

In that case I am assuming then that there is NO minimum distance to joists etc. there is absolutely no mention joists or ceiling voids heights etc in the instructions. It just says "under no circumstances be covered with insulation". They are CED code DFPAD10. I will check the manufacturers site as one last check......