LED downlighters and fire hoods

[TheMidge]

I have been refurbishing my house and want to install LED downlights at ground floor level. The rewiring is being done by a fully qualified electrician (part p) but I am supplying all the materials. My house is three storey, so no compartment floors and 30mins fire protection required. The LED downlights I have purchased (made by ELco) do not have replaceable lamps. They are solid aluminium (no holes and pretty substantial) castings and fit in a 70mm hole, retained by spring clips. There is no mention of them having any fire rating (though to look at them they would clearly be pretty good at holding back a fire) so I have bought fire hoods for all of them. The problem is that with such a small hole the hoods are proving impossible to fit (I have 100mm Rockwool in the floor void to aid sound insulation which isn't helping). It might be possible to fit hoods to some by ripping up T&G floorboards above and pulling out the insulation so I can work from above, but I suspect that the end result would be that the floor had less fire resistance than if I hadn't bothered! Both my electrician and I are wondering if its really necessary. I have read the Bill Allan article on 'installing recessed luminaires in ceilings' from the Wiki in this forum which has given me some cause for hope, as my LED downlighters have to be superior to the type of downlighters used in the 1996 TRADA tests.

Ceilings are 12.mm plasterboard and skim, joists 175mm with 100mm Rockwool between (previously 9.5mm p/b and artex). I also have linked mains fire alarms to every room (except the bathrooms) so have done a lot to upgrade the safety of my house compared to what it was . I have also just now written to the lighting manufacturer for their thoughts.

My electrician works on the 'precautionary principle' and needs just a little more before he is willing to sign it off without the hoods. Does anyone have any views or additional material that might help us decide what to do (hopefully not to put my LED lights on Ebay!) Many Thanks

 

[Chri5]

Fire hoods are not a requirement.

The regs are often read incorrectly, fire hoods are only required for downlighters between flats or buildings with more than one dwelling.

So a old house split in to 2 x flats (grd and 1st) the grd owner would have to provide hoods, same with flats.

If you own and use the floor above as part of your house they are not needed.

The d/lights need air around them so the insulation should be cut back and a 100mm air gap provideed around the fitting. The sparks should also derate any cable in the insulation material.

 

[holmslaw]

..

 

[TheMidge]

I did wonder if 3 storey made a difference. My reading of the Building Regulations is that for 3 storey houses floor integrity and insulation require 30mins (up from 15 mins) and loadbearing capacity stays at 30 mins, but still all are no more than 30mins. Maybe a friendly BCO may see this and correct me if I'm wrong.

 

[Chri5]

Are you sure? I thought fire hoods were required in 3 storey houses.

I'm not sure now !

So what would happen in a dwelling that converts from 2 storey to 3 storey via a loft build ?

 

[ban-all-sheds]

People I know who have done that have had to fit self-closing firedoors everywhere, so maybe the ceilings have to have their fire resistance upgraded too.

OTOH, stand at the foot of the stairs in any house > 1 floor and look up and you'll see an enormous hole in the ceiling...

 

[TheMidge]

The position is certainly different for three storey house compared to 2 storey. Many years ago I was a BCO and then the new floor had to be 30mins, and the existing upgraded to that level (usually by puting hardboard over the floorboards if they weren't already T&G) but lights didn't really come into it. In my case I have existing ceilings of 9.5mm pb and artex, and T&G floorboards so I suspect not full half hour. To resolve this I have had the entire first floor ceiling skimmed with plaster, and at ground floor level I have taken down the original P/bd in order to run my plumbing/ch pipes through, and 100mm Rockwool in the floor void, then reboarded with 12.5 p/b and skim, so upgraded quite a lot, certainly to full 30mins at least until the holes went in for the lights!

Have heard back from the manufacturer that the lights aren't fire rated, but I guess that doesn't mean they wont provided some protection, just not 60 or 90 minutes. I have attached a picture showing the rear of it, I don't think it would compromise the ceiling too much, particularly taking into account the comments in Bill Allans article //www.diynot.com/wiki/electrics:lighting:downlights:firehoods. Any thoughts?

Untitled

• TheMidge
• 20 Sep 2010
• 1

 

[holmslaw]

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[TheMidge]

If a downlighter is fitted into a ceiling void where the only source of fresh air is from the room below, then yes it will take a long time for a fire to break through. But if fresh air from elsewhere can enter the void or this was the top floor ceiling, it would be a much more serious situation due to the fire feeding on and spreading towards the source of fresh air.

That would be my situation, no other ventilation to the floor void, and the lamps themselves seal their fixing holes.

It's a bad idea to deliberately compromise fire compartments and ignore fire regulations.

Of course everyone would agree with that, and this is exactly what I want to establish. The floor is not a compartment floor, so that bit is OK and only a 30 minute requirement. The regulations themselves are as always just written in general terms though the approved document gives the following guidance

'Where downlighters, loudspeakers and other electrical accessories are installed, additional protection may be required to maintain the integrity of the wall or floor'

This is my dilemma, additional protection may be required, but is it required in my case, or is my proposal fine as it stands. The test reports basically says that small openings for downlighters don't compromise the integrity of floors that are required to provide fire resistance of up to 30 minutes, so far so good. In my case the holes will be filled by lumps of cast aluminium, which must hold back the fire for 5 minutes at least before the fire gets into the floor void, then the rockwool which is fireproof will give further protection. Both of these elements weren't there in the TRADA tests and still that floor was found OK. To me this says that 'additional protection' should not be required in my case.

If I can't use my downlighters as they are, then for about half I will have to install fire rated downlights that take GU10 LED lamps (I'm trying to save the planet!) For the remainder I could rip up the floor boards and insulation to fit the fire hoods, or just use more fire rated downlights and more LED GU10's. To replace all the lights I have bought with Fire rated downlights and GU10s will cost me another £700 on top of what have already spent for my current lights so not something that I want to do if its not necessary.

 

[holmslaw]

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[TheMidge]

And you said 'Many years ago I was a BCO' either youravinalarf or you were a typical untrained irresponsible borough council employee. It's the contract staff that do the work and make decisions in our borough councils.

Good luck with whatever you decide, I'm out.

I'm really sorry, I'm new to this, I cant see what I said to upset you but I apologise anyway, and I'm grateful for your input.

 

[TheMidge]

For anyone following this thread I have just found this interesting document, thought it might be useful to post it here:

http://www.eastdevon.gov.uk/bc-guidancenote4-downlighters.pdf

It appears to be a guidance note issued by LABC and reads like it is aimed at BCO's, even though I'm sure many authorities like this one make it publicly available.

The relevant section is this bit:

BUILDING CONTROL
GUIDANCE NOTE 4
GUIDANCE NOTES FOR CONSTRUCTION PROFESSIONALS ON THE USE OF DOWNLIGHTERS IN DWELLINGS

Introduction
The use of downlighters is becoming increasingly common in dwellings and domestic extensions. This fact combined with recent amendments to the Building Regulations has prompted debate on their compliance between Building Control Surveyors and other construction professionals.
The purpose of these guidance notes is to consider the areas of concern and demonstrate how they can be specified in order to accord with the requirements.
Subjects covered include fire safety, sound insulation and the conservation of fuel and power.

Fire Safety
Approved Document B of the Building Regulations includes requirements that floors in dwellings achieve a fire rating. This is normally 30 minutes for low rise buildings where the floor is not a compartment floor. When installing downlighters in such a floor, the question arises as to whether or not they will adversely affect its fire resistant properties to the extent that it will not comply.

Whilst there is not a great deal of research information available on this subject, tests sponsored by the DETR (now ODPM) and carried out by The Timber Research and Development Association* provide useful guidance. The view of many Building Control professionals is that additional protection in the form of intumescent covers, boxing or fire resisting fittings is a necessary provision in all cases. It may be that these are opinions that have been influenced by commercially driven advice from companies dealing in such products. It is important that our decisions are based on sound and independent scientific research, it being all too easy to ask for a higher standard knowing that we are unlikely to be challenged.

The above tests were carried out on typical timber joisted floors (measuring 3.2m x 4.2m) fitted with up to 24 plastic and metal clipped fittings of various diameters. All indicated that the unprotected downlighters did not cause premature failures in terms of load bearing capacity, insulation or integrity. It could be argued that such ‘laboratory’
standards do not represent a floor after the retrospective removal of areas of floor decking. Such concerns are weakened by the fact that patched areas are inevitably supported on noggins or joists and the tests included decking that was not tongued and grooved.

Similar tests on 60 minute fire resisting floors also did not show premature failure. This small scale evidence is sufficient to negate the need for downlighter protection in 60 minute floors. Full scale evidence may be more onerous so in the absence of such information, covers should be provided.

It is also important that these tests are not seen as being representative of other floor types such as those incorporating engineered ‘I beam’ joists. Such members have little ‘sacrificial’ timber so rely almost entirely on the integrity of the ceiling lining to prevent failure in fire. Protective measures are also essential in this type of floor.

(I have missed out a whole chunk here on sound/thermal issues)

Conclusion

From the above it is clear that designers and builders can incorporate downlighters as part of a lighting system to a dwelling without having to contravene the Building Regulations. Building Control Surveyors must be vigilant against being influenced by potentially biased information from the commercial sector. We have some excellent sources of independent advice that we can use to make balanced judgements when checking designs or work on site.

* Trada Technology Report 1/2001
Timber frame walls and floors: Fire resistance of service penetrations
ISBN 900510 28 6
[email protected]

 

[Steve]

Listen, the reason you have lost holmsaw from this thread is that you have come here asking for advice, but ended up telling us all about your experiences etc. I havent read the whole lot, but it seems like you are perfectly capable of finding the answers to your questions yourself.

And most BCO's dont debate, as that article suggests, they just "know they are right".

 

[TheMidge]

Point taken, though I packed in being a BCO 22 years ago, and lots has changed since then so I was seeking advice, as well as researching for myself.

Anyway, I'd like to think I wasn't the sort of BCO that Holmslaw describes as 'typical untrained irresponsible borough council employee' and to be honest I never met any like that (your version is fairer there were one or two that thought they were always right). As for untrained the ones I know are mostly either Chartered Surveyors or Engineers (or both). I think BCO's get an unfair bad press (for the most part) but maybe I'm biased.

Thanks for everyones input, hopefully I won't get off on a wrong footing next time.

 

[ban-all-sheds]

I cant see what I said to upset you but I apologise anyway.

Nothing, and you have no need to.