How do Fire Rated Downlights Work?
Ceilings work as one of the most important barriers to slow the spread of fire. When we install recessed lighting we must cut a hole in the ceiling, weakening the barrier allowing flames to spread between floors more easily and causing ceilings to collapse within just a few minutes. This is why we use fire rated downlights.
Fire rated downlights have a layer of intumescent strip, a material that expands in heat, used to seal the discontinuity in the ceiling ensuring its structural integrity is maintained.
Which Fire Rating Do I Need?
The necessary fire rating of your downlights depends on the structure of the building, particularly the number of floors. Downlights are rated 30, 60 or 90 minutes, suitable for different ceilings. Higher up in buildings, where the ceilings will need to last longer will require a 90 minute fire rating, whereas lower down in the building will need less. The choice of downlights will depend on the ceiling itself and how long it is designed to last.
Do I Need Fire Rated Downlights?
In order to protect people in floors higher in a residential building must have higher protection. For a dwelling where the height of the top floor is 18m or below, the ceilings should have a resistance of 60 minutes. For taller buildings, up to 30m, the requirement for ceilings is a 90 minute and thus the downlights must be fire rated to the same level.
Regardless of what type of building downlights are being installed in, The Electrical Council (ESC) recommends always using fire rated downlights.
What is Acoustic Rating?
When you cut holes in your ceiling for downlights, you not only weaken the ceiling in case of fires but also leave gaps allowing sound to travel through. Acoustic rated downlights are used to ensure that the sound that travels through the downlight hole is no more than if the hole was not in the ceiling.
This is tested using specialist audio equipment. A sound is produced in the test room, which is measured through the ceiling. We use this measurement as a base line to compare to. We then cut holes in the ceiling and install the downlights. The same sound procedure is used again, this time we compare the results to the base line. If there is no difference in the sound that can be detected then the downlights are acoustic rated.
Fire and Acoustic Rated Downlights