I assume the LoftCap would meet this requirement?
If not, do you mean some form of moisture barrier, similar to the material used under laminate flooring? If so, how would this work with regards to installation?
Downlight choice and installation method
- Thread starter AnimalGlu
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If not, do you mean some form of moisture barrier, similar to the material used under laminate flooring? If so, how would this work with regards to installation?
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Sorry to highjack the thread but i've recently bought some lights from john lewis to be installed in a conservatory and after speaking with my electrician he says these light are fire proof but they as they do not have built in hoods he thinks he'll probably have to get some, is this right or can they be placed into the ceiling without these hoods?
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@eagle8
if you are sorry to highjack the thread, it is simple..... don't : start a new one.
@AnimalGlu
Sorry, I don't know what Loftcap is. The simplest and cheapest vapour barrier is a poly sheet of whatever thickness you deem necessary. This is always needed, but absolutely vital with downlighters as the (rising) heat generated really pumps air ( always moist inside the house) through the cut-outs and unless blocked will cause severe condensation.
if you are sorry to highjack the thread, it is simple..... don't : start a new one.
@AnimalGlu
Sorry, I don't know what Loftcap is. The simplest and cheapest vapour barrier is a poly sheet of whatever thickness you deem necessary. This is always needed, but absolutely vital with downlighters as the (rising) heat generated really pumps air ( always moist inside the house) through the cut-outs and unless blocked will cause severe condensation.
There is a specification sheet listed on this page.
Seems quite good but I really don't know if they perform like they say in the field.
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Hopefully you are not suggesting placing a polythene sheet over downlighters?
If anyone did this, the polythene would be melted in seconds, and could easily cause a fire.
The Loftcaps do seal against vapour, but they must be sealed to the back of the ceiling with adhesive, and the cable entry hole must also be sealed. (The instructions for them state this also).
It sounds like neither of you know what you're talking about.
Fire proof? In what way?
What makes either of you think that on a glazed conservatory ceiling there would be a requirement to prevent the spread of fire to the floor above? NO fire rating is nessecary.
BUT given the material structure of most conservatorys - plastic, it would be wise to consider F marked fittings - these are fittings designed for mounting in flammable or heat-deformable surfaces. The F mark is an F inside an upside down triangle.
Dont use fire hoods or fire rated fittings. These will have the undesireable effect of holding heat close to the area, which will discolour the plastic.
How do you install recessed lights into a conservatory ceiling in the first place?
Good question, there's a void running around the outside of the conservatory, between the ceiling and sides, where the downlighters will go.So is there a difference between fire marked and fire rated? And should i advise him against getting the fire hoods? Also could this be demmed a fire hazard if they were to have fire hoods?
Any help on the matter is appreciated as 1. i want my conservatory to be right and 2. i'm curious about the heat that downlights give off.
Yes.
You don't need fire hoods, but they should not create a hazard.
What you should be concerned with is this:
Your electrician is supposed to certify that the work he does complies with the Building Regulations. All of them, not just Part P.
And he clearly doesn't understand the Building Regulations, which makes me wonder how on earth his declaration about compliance with them can have any value. What else does he not know about and yet still claims he does?
Ban-all-sheds
So what your saying is that i don't need fire hoods, but if they were to have fire hoods then there would be no danger of them causing a fire?
Also i like the look of the above lights do you know where i can pick some up?
So what your saying is that i don't need fire hoods, but if they were to have fire hoods then there would be no danger of them causing a fire?
Also i like the look of the above lights do you know where i can pick some up?
There shouldn't be, because the makers should have ensured that they leave enough clearance around the lights. But check with the specs for the lights.
Did you not try clicking the photo?
Halogen downlights get hot. Very hot, enough to burn things such as your fingers, paper, timber and other debris commonly found in lofts and similar places.
Fire hoods are cloth-like bags or cones which are placed over the top of downlighters. This means that access from above is required to fit them properly.
Their purpose is that if a fire occurred in the room below, they expand into a non combustible char, which will seal the downlighter holes. This will prevent fire spreading into the room above for a certain amount of time.
Fire rated downlights are those which are partially enclosed on the back, usually with a metal cannister, and contain similar materials to the fire hoods which expand to fill any holes when there is a fire.
Both fire rated downlights and other types with fire hoods are still capable of causing fires when incorrectly installed, and they will easily discolour or melt ceilings made of timber or plastic.
Fire rated downlights or hoods are only needed where the ceiling forms part of a fire compartment. In almost all domestic situations, this will NOT be the case. One exception would be the ceiling of an integral garage, however it isn't too likely that downlights would be fitted in there. Another example would be in a block of flats, however these would normally have concrete slabs for the ceiling, so downlights couldn't be fitted anyway.
F-marked items (those with an inverted triangle containing the letter F) are those which can be mounted on a normally flammable surface. They will have been designed in such a way that the parts in contact with the ceiling won't get hot enough to cause a fire. They may still get hot, and might cause discolouration of some surfaces.
Where the triangle has a line above it, this indicates insulation can be placed over the fitting without causing a fire.
If there is no symbol, or the symbol is crossed out, it can only be mounted on non-combustible surfaces and must not be covered with insulation. This applies to a majority of halogen downlights.
Leaving big gaps in the insulation is no good either, as this will contravene other parts of the Building Regulations.
Another significant issue with downlighters when fitted in rooms with an unheated loft space above is that the hole will provide a route for warm air from the building to enter the cold loft space. This results in condensation in the loft and leads to mould and rot.
This is prevented by either using the loftcap, or constructing a sealed box around the back of the downlight. Sealed being the important part - otherwise air will still enter the loft space. For this reason, items such as flower pots or those metal loft braces are useless, since they do not provide any kind of seal.
I suspect that a clay pot large enough to provide the necessary clearances for the lights would be too heavy.
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