in this q and a video we're going to answer the question what does a 30
60 or 90 minute fire rating mean for a ceiling
this question relates to the video that we made recently on the Prism Pro fire rated downlight
from Ansel with all the great features that they had especially that lovely colour tuning function
and if you're interested in fire rated ceilings from an installation point of view then please
do go and check out our free training module on this subject it's fully accredited by CPD UK and
you can take it from the comfort of your own home anytime click the link in the description below
or head over to the knowhow page of efixx.co.uk to view the full range but to answer the question for
this video let's think about what a fire rating means for a ceiling now we're going to keep it
fairly simple for this video because there's much more technical detail in the training module i
mentioned a moment ago there's a little bit of a misconception about this issue that when we refer
to a fire rated ceiling and that rating of 30 60 or 90 minutes that this is referring to the amount
of time that the plasterboard on the ceiling can withstand the passage of fire before it degrades
and the fire can pass through to the joists above unfortunately this is not true the plasterboard is
absolutely critical to the fire resistance of the ceiling as we'll see in a moment but the amount
of time it takes for fire to pass through it is not the point at which the ceiling has failed
there's several dangers associated with a fire breaking out in a room below an occupied space
above but the one we'll focus on just for now is the risk of collapse after all the ceiling above
a downstairs room is part of the floor below an upstairs room and if a fire breaks out in the
room below it could burn away the joists and the flooring material leading to the whole structure
of that floor collapsing if that floor forms part of an escape route for someone in the rooms above
then they're not going to be able to exit the building and puts them in serious danger of harm
or even death so instead of thinking about a ceiling as being just a plasterboard we need
to think about the plasterboard the joists and the flooring material above as being a
system of combined materials that go together to create the structure between two floors
so now the idea of 30 60 or 90 minutes starts to make sense when you realize that that is how long
the ceiling and floor structure is designed to last without collapsing in the event of a fire
not how long it takes for the fire to pass through the plasterboard so how does this affect you and
your installation work well in the choice of your recessed downlights obviously if you cut a hole
into a plasterboard ceiling then you're creating a space that fire can pass through more easily
and could be decreasing the amount of time the floor above will keep its integrity so you've got
to make sure that your light fitting is matched to the ceiling type that you're installing it into
in other words it has to have been tested and proved to be an acceptable part of the floor and
sealing system so if you're installing a fitting into a 90 minute rated ceiling you have to make
sure that it's rated to 90 minutes now at this point don't fall into the same trap that many
people do of assuming that a fitting mark only with a 90 minute rating must be good for all the
ceiling types it can actually be more challenging for a manufacturer to create a fitting that can
pass the 30 minute test than the 90 minute test there's some other serious considerations that we
need to think about when we start cutting recessed fittings into ceilings such as how do you identify
the fire rating of a ceiling and what's the impact of the type of joist that's used to
make up the flooring spoiler alert it has a huge impact on the choice of light fitting and can even
affect if the house gets signed off as approved for occupation or not so if you'd like to make
sure that you don't fall fail of the planning officer then please do go and check out that
free training module we mentioned earlier it won't cost you a penny and it could help you keep your
installations compliant so there we go that's what it means to have a 30 60 or 90 minute fire rated
ceiling but as always we want to hear from you do you always make sure that your recessed light
fittings match the fire rating of the ceiling have you ever thought about what joists are above the
plasterboards and the difference it can make to your lighting whatever your thoughts and questions
please leave them in the comments section below and as always thank you very much for watching
you