Fire rated emergency mini down lighter........

Hi all,

I have a question....

Does anyone know of a fire rated emergency mini downlighter that has been specified for use within a metal web (posi joist) ceiling? Fire rating must be 60 or 90min due to joist depth.

I am struggling to find anything other than converting a fire rated standard mini down lighter, but am limited as the conversion pack needs to be installed through the cut out as zero access from above. The smallest (diameter wise) kit I can find is 42mm and discrete is the name of the game with this project. I would like stay clear of a remote battery system if at all possible......

Any ideas of products would be amazing!

Cheers,

FFM

Have you looked at Ansell

Hi UNG,

Yeah, I spoke with their tech services earlier this week and none of their emergency down lighters have a fire rating. Bit surprising really....

How about KSR lighting
https://ksrlighting.com/amfile/file/download/file/11453/product/7097/
This datasheet lists emergency options

Hi UNG,

Yeah, seen these but only tested against solid joists and not web joists! Their range is also too large (physically) for the project! It's a real pain.

I have a plan B, which is the conversion of standard mini downlighters (cut out 42mm, bezel 48mm) but am getting some grumbling re the standalone LED indicator that will also need to breach the barrier from the FO. The designer squawked when `I mentioned the discrete, twin spot units like the Lluma emlux.....

I have spoken with various fire companies and they dont have any suggestions either... I know that the new `google building in London is an all timber construction with web joists, so might also try to see what they did.

Grrrrr!

Wood is wood, so I'm not sure how much difference web v solid timber makes, if any?

Hi Binky,

Great reply! Shared it with the site manager and lead designer. Site manager did smile (a bit!) but the lead designer didnt!

On a more serious note, if anyone does have any info on a fire 30. 60 or 90 min rated mini down lighter rated against web joists please pass this on!

Cherers,

FFM

FFM said:

Hi Binky,

Great reply! Shared it with the site manager and lead designer. Site manager did smile (a bit!) but the lead designer didnt!

On a more serious note, if anyone does have any info on a fire 30. 60 or 90 min rated mini down lighter rated against web joists please pass this on!

Cherers,

FFM

Click to expand...

I have a lifetimes worth of experience in stating the bleeding obvious

Ok, more serious note, if the downlighters are designed not to set fire to whatever ceiling material they are fitted too, which could be anything from pvc facia boards to plasterboard to wood cladding, then why would they set fire to any form of joist, web or solid. I have seen downlighters where some prat has literally holesawed through supporting timbers - not so much as a scorch mark, and those were halogen.

It's more about the spread of fire and smoke through the void spaces and not about wether a down lighter or fitting catches fire. Solid joists prevent the spread of fire and smoke for longer than web joists and can support a floor longer and thats the key from an install point. How fire and smoke will penetrate through different materials dictates what type, and rating, of fitting can be used. Each type of ceiling and joist will, and does, behave differently to another. Understanding this will affect selection of the components installed. An obvious analogy is Grenfell, which has changed how and what we install.

A 30 min rating for a down lighter in one ceiling does not mean that it is 30 min rated in all ceilings and so on.

Hence my ask....

I hope this makes sense.

Right, so now we know what the real concerns are.

I would think that is more to do with construction standards, and fire detection. A school I work in has a new build block with web joists, above suspended ceilings. All voids have fire detection in them, all electrical fittings are standard stuff. Each void has concrete fire partitions between them ( basically one void per classroom) the issue then is any services penetrating a fire wall are suitably sealed with intumescent materials - something I understand didn't happen in Grenfell. No electrical items such as junction boxes or cable runs are fitted to the wood in any of the voids, they are mounted to the concrete or cable tray ie non flammable surfaces where ever possible.

The whole point of fire rated downlighters etc etc is to prevent fire in a room penetrating the voids, ie not be the weak point in a fire rated ceiling, so spec of those, in my mind, is nothing to do with fire travelling through the voids, they just have to match the fire raring of the surface they are mounted to. Eg 90 min ceiling needs 90 min fire rated downlighters.

binky said:

The whole point of fire rated downlighters etc etc is to prevent fire in a room penetrating the voids, ie not be the weak point in a fire rated ceiling, so spec of those, in my mind, is nothing to do with fire travelling through the voids, they just have to match the fire raring of the surface they are mounted to. Eg 90 min ceiling needs 90 min fire rated downlighters.

Click to expand...

exactly. as long as the fire rated lights match the fire rating of the surface they are going through, then they are adequate

Hi Binky,

If your new block has suspended ceilings, then the electrical fittings are not installed into the ceiling thats attached to the web joists. That said, if you are saying that the new block has emergency lighting that is recessed into the ceiling that the web joists are physically attached to, can you pass on the details of that kit? I can then get the data for its testing within web joist ceilings.

Unfortunately, knowing that a fixing has a rating of 30, 60 or 90 minutes in ceiling A with joist type B, no longer means that it's OK in ceiling A with joist type C. If you chat to your local FO he will confirm that and if you talk to the lighting manufacturers, they will state that their fitting are only OK in the specific environments that have tested them in. They will not guarantee compliance for systems they have specifically not tested. In this case, they will not guarantee their recessed emergency down lighters in a fire boarded ceiling with web joists. As mad as this may sound, thats how it is.

There are many reasons for this, not just those I mentioned in the posts above but also thermal conductivity through fittings. Heat has a major impact in the void space and the type of joist will affect this. Different fire rated fittings will also have different thermal conductivities, which means they will behave differently under high temperature and may cause differing effects in the void etc etc.

Dont get me wrong, I totally agree that a 30, 60 or 90 minute fitting will provide that cover in ceilings. The issue is, that the FO now requires data to prove that a fitting is compliant within the system specified. Web hoists are new-ish to the market and do behave differently to solid joists when exposed to fire or heat. Without having the data that specifically applies to this style of install, I cant fit any recessed fitting that hasn't been shown to be compliant.

Sooo, if you do have recessed mini emergency lights in the new block ceiling, I would greatly appreciate if you could pass on the details of what they are.

Cheers,

FFM

the block is panel lights in the suspended ceiling, as in light weight foam type tiles on a metal grid. . Being around 10 years old, things will have moved on since it's construction.

Sounds like your only option is to go back to the manufacturers, or get FO to do something useful....

What exactly are you building, flats, houses? Web joists aren't that new, I rather like the ease of throwing cables through them, but apart from the school, I've only encountered them in domestic extensions.

OK, thanks for your input. Appreciated.

Does anyone else have any recommendations for fire rated emergency down lighters in this system?

RE Binky - the install is into a two story, glass fronted structure thats pretty cool, It will form part of a climbing center in Bristol and will function as a reception area, atrium entrance, seating area, shop, kitchen, bar, viewing area, yoga center, office space and cafe. It's phase 3 of 7 in terms of the build. These are into the UGF.

I am not building it but am spec-ing/designing and installing the electrical side of it. the following phases will include the design of the lighting and power into the new LGF climbing area, gym, LGF toilets etc etc etc.