downlights in pitched roof

[sammoseley]

hi,
having a pitched roof put in on 5" joists with celotex insulation, wanted to put downlights in, BCO is saying only if fitted with fire hoods and there is room for insulation above, I am not aware of any fitting that will allow this in the space available so I think its a no-go, just wondered if anyone knew any different, ie. if there is some shallow fitting available for this, which will fit within 5" gap and still allow room for insulation above.
any info much appreciated
cheers
sam

 

[dunny123]

I have fitted loads of GU10 downlighters in vaulted ceilings and have just used firerated ones. I ensure the builders leave a 150 square void in the cellotex around the proposed locations before they overboard with plasterboard. BCO have either never noticed or ever been bothered about it. I know it knackers up the thermal qualities of the ceiling but most people would rather have the downlights than the insulation with surface mount fittings.

Alternative: tell BCO that you are not having downlights but put 1st fix cables in anyway. Put them in after its been signed off ! (its quite easy to remove enough cellotex around the fittings afer you have cut the holes to allow free air around the fitting)

 

[sammoseley]

thanks for the info, BCO aside i'm struggling to find any fittings that don't require more room than the 5" clearance, when you look at the fitting instructions.

 

[Chri5]

GU10 fire rated (so no need for caps / hoods)- None on the link below are more than 110mm (5" = 125mm)

http://www.tlc-direct.co.uk/Main_In...x/Downlights_Mains_Voltage_Halogen/index.html

 

[electronicsuk]

Perhaps you can find something low-profile that uses a GX53 lamp?

 

[ban-all-sheds]

There is no requirement for fire-hoods or for fire-rated downlighters unless you are perforating a fire compartment boundary, and as these will actually be in the roof you are clearly not doing that.

Unless you need to keep your BCO cooperative for other reasons, demand that he finds a regulation which forces you to install hoods etc.

I have to say though that I'm very suprised he's allowing them at all, since the holes in the insulation will compromise the performance of that thermal element, and that is a contravention of the Building Regulations.

 

[ban-all-sheds]

Alternative: tell BCO that you are not having downlights but put 1st fix cables in anyway. Put them in after its been signed off ! (its quite easy to remove enough cellotex around the fittings afer you have cut the holes to allow free air around the fitting)

Why do you think that advising people to break the law is appropriate?

 

[sammoseley]

BAS I'm sure you're right about the fire aspect, if I question him on it he may accept they aren't necessary
in fact he told me that ALL downlights nowadays, wherever they are installed, have to be fire rated ones wich surprised me a bit

as you say it's also the insulation he's concerned about, so maybe I can put some other insulation in above the downlights, where the cellotex has been cut away, ie. something much thinner which will still do the job. if such a thing exists.

cheers
sam

 

[ban-all-sheds]

If it's thinner it won't work as well, which probably means it won't work well enough.

Also - what about vapour control?

When you cut holes in the Celotex you'll also be perforating the membrane which stops moist air from getting into the unconditioned space above, condensing, and rotting the roof timbers.

 

[Chri5]

unconditioned space above

Its that strictly true ?

The roof is likely to have a requirement for air vents and the air space does have some movement due to soffit venting and airflow between soffit and roof tile vents.

 

[ban-all-sheds]

Yes, but that's all movement of air between the ambient temperature loft and the ambient temperature outside...

 

[SamHandy]

I came accross these the other day, they require a 110mm, but with air gap 135mm which is about your 5".

http://www.aurora.eu.com/ProductPages/LampProductDetails.aspx?g=5960&c=375&b=71&oc=375

They also do mains voltage ones AU-DLM901

Maybe that will help. Just be grateful that he hasn't asked for 'Low' Energy fittings as yet.

 

[ban-all-sheds]

I came accross these the other day, they require a 110mm, but with air gap 135mm which is about your 5".

So there'll be no insulation whatsoever over an area of 270cm² where each luminaire is. Or a great deal more if the transformer needs to be uncovered.

sammoseley - check with your BCO before you buy any lights or cut any holes.

 

[matt1e]

Alternative: tell BCO that you are not having downlights but put 1st fix cables in anyway. Put them in after its been signed off ! (its quite easy to remove enough cellotex around the fittings afer you have cut the holes to allow free air around the fitting)

Why do you think that advising people to break the law is appropriate?

from another thread

It depends what I am doing, i.e. if someone was paying for new materials then I will use new materials.
If on the other hand I am repairing something old I may opt to use the old coloured cables as to avoid confusion.

No reason that you can't do both, if you have new (as in not previously used) cable in old colours.

is this not condoning breaking the law Ban?

to be honest I would do the same but I would say it would still be illegal to use old colours (unless finishing of a job started pre april 2006)

you can not use a departure for something that is illegal!

this has always been my view on it debate welcomed (maybe should be a new thread)

__________________

 

[ColJack]

it's not illegal is it?
they are recomended colours and BS7671 is not law..