I came in at a rather late stage in the project where a old office building is being converted into a hotel. The wiring for the lighting was mistakenly routed above the compartment ceilings in the floor void above. The ceilings then had a small number of recessed downlights which were fire rated at 90min. The arrangement has been rejected by Building Control as there is no test evidence for the composite. So be careful when going for similar arrangements! I imagine recent serious fires are beginning to have an impact on the way regulations are interpreted.
I get the drift of what you’re saying, however can you clarify what the composite is?
I am assuming that with the cables in the void above what is probably fire rated plasterboard, possibly double boarded they and the downlights that are presumably rated less than the ceiling branch the fire protection.
Back in the 1970’s I worked as a carpenter for Westbury Homes, I was going to put a set of floor joists on and another carpenter said to stick precisely to the plan as many carpenters did not do so.
The joists were set out on the plan with precise measurements and there were some full depth noggins without an explanation of what they were for, they actually formed boxes within the floor void, the plasterers had to line these with a double layer of plasterboard and tape them before the kitchen ceiling was boarded and Artexed as they formed a fire resistant box for the downlights to be installed in by the electricians.
In the forty years since then I have never seen another builder take such care when installing downlights, it wasn’t difficult it just needed organising and paying for.
This is interesting, as I think there are quite a few buildings where fire rated plasterboard was used but have quite large holes with downlights and other things coming through it.
Less than a year ago on one ceiling I have used the new LED down lighters that are only about half an inch deep and are surface mounted on the show side of the board, and nary a murmer from building control at that point. Still there is a small hole where the wiring comes through, but that can be sealed more easily.
I'd be very keen to hear what this building control dept are happy with, as others note, a general focus on better fire compartmentalization seems to be on the cards - and given the state of some places it is needed.
Is that a ground floor plus 1 or a ground floor plus 2.
I am asking this as my thinking is the majority of houses with ground floor plus 1 are one fire compartment. In which case no need, but a good idea, for fire rated down lighters. My thinking is any fire will vent up the stairs and not be impeded my fire rated doors with closers.
Once you have a ground floor plus 2 the 2nd floor will usually be a separate fire compartment with fire rated doors and a window that can be used as a means of rescue by the FS. In which case fire rate down lighters fitted in the 1st floor ceiling need to be fire rated.
Is that a ground floor plus 1 or a ground floor plus 2.
I am asking this as my thinking is the majority of houses with ground floor plus 1 are one fire compartment. In which case no need, but a good idea, for fire rated down lighters. My thinking is any fire will vent up the stairs and not be impeded my fire rated doors with closers.
Once you have a ground floor plus 2 the 2nd floor will usually be a separate fire compartment with fire rated doors and a window that can be used as a means of rescue by the FS. In which case fire rate down lighters fitted in the 1st floor ceiling need to be fire rated.
