Fire hoods for downlights, will this work

[anobium]

Just had to replace 2 downlights in the kitchen over a single storey annexe and realised there was no fire protection hoods over the original lights.
On closer inspection found that it was not possible to gain access within the roof to fit hoods over lights.
They are at a point behind a purlin where the ceiling is underdrawn to the rafters.
Anyway after giving the matter a great deal of thought and not coming up with any answers, SWMBO offered her tuppence worth of advice.
Why don't you wrap it up with the silver foil that I use for baking!!!!
Now I am no expert , but I cant see anything wrong with her suggestion,
Anybody got any ideas on this , is it feasible or is there some flaw that I cannot see.?

 

[Chri5]

How are you going to prove a 1 hour fire rating with foil


You might not know, but fire hoods aren't required in the dwelling is yours, they are required when the dwelling above is another persons!

If there is a need, why not swop out the fittings for ones that have a fire rating on the fitting and as such have no need for hoods?

 

[EFLImpudence]

Don't they use foil to keep things warm?

 

[ban-all-sheds]

Why don't you wrap it up with the silver foil that I use for baking!!!!

Because foil will not swell up in the presence of heat from a fire to close off paths through the light to hamper the spread of fire. It might cause the lights to overheat and/or cause a short circuit and start a fire though.

As Chri5 said you don't need them anyway.

But what you do need is to completely seal any paths where water vapour could get through, so good luck with that if you have no access from above. Did you notice if your roof has started to rot yet?

 

[anobium]

How are you going to prove a 1 hour fire rating with foil

You might not know, but fire hoods aren't required in the dwelling is yours, they are required when the dwelling above is another persons!

If there is a need, why not swop out the fittings for ones that have a fire rating on the fitting and as such have no need for hoods?

Already fitted them, More concerned with my families safety, but thanks anyway

 

[anobium]

Don't they use foil to keep things warm?

Yes but they also use it to deflect heat.

 

[anobium]

Why don't you wrap it up with the silver foil that I use for baking!!!!

Because foil will not swell up in the presence of heat from a fire to close off paths through the light to hamper the spread of fire. It might cause the lights to overheat and/or cause a short circuit and start a fire though.

As Chri5 said you don't need them anyway.

But what you do need is to completely seal any paths where water vapour could get through, so good luck with that if you have no access from above. Did you notice if your roof has started to rot yet?

.

I take it your referring to an intumescence strip but these only come into effect when the fire has started.
My prime concern is to prevent excess heat permeating the surrounding insulation, and in anyway the foil would only be above the light which is no difference surely than a conventional hood.
Not sure about your reference to water vapour but in any event the roof is in excellent condition

 

[Taylortwocities]

Unless the downlights conform to Building Regulations Part C (Resistance to contaminants and moisture), the heat of the lamps will draw moisture up through the light and deposit it in the roof void.
There it will condense on roof timbers, etc which will rot over time.

If there is no access to the roof space I am not sure how you can assert

the roof is in excellent condition

 

[ban-all-sheds]

My prime concern is to prevent excess heat permeating the surrounding insulation

Ah - so you do want to start a fire, by trapping the heat that the lights generate, thus making them get hotter and hotter.

 

[flameport]

I take it your referring to an intumescence strip but these only come into effect when the fire has started.

Exactly - that's what fire rated lights and fire hoods are for. It's also why they are almost never needed.

My prime concern is to prevent excess heat permeating the surrounding insulation

Fire hoods and fire rated lights have nothing to do with that.
The way to prevent heat from building up and causing a fire is to install the lights with sufficient space around them to allow the heat to dissipate. These distances are usually specified by the manufacturers of the lights but are usually 150mm or more.

Some companies make frames or other covers which prevent loft insulation and other items from falling onto the lights. Some people use plasterboard boxes, terracotta pots and similar items for the same reasons. These can be useful, but they can only be fitted from above, and they are not fire hoods or anything of the sort.

Then there are those people that leave big holes in their loft insulation to prevent downlights overheating - this causes excessive heat loss from the rooms below and won't comply with building regulations.