Rodney Simmons, Technical Communications Manager at JCC Lighting, highlights Part B Building Regulations and the importance of ensuring that fire rated downlights fully comply with these.
The purpose of Part B Building Regulations is to ensure building structures provide adequate safety protection to occupants in the event of an emergency evacuation of a structure/complex. This regulation has been a legal requirement since 1987.
The level of fire resistance required for a ceiling is proportional to the potential risks involved. For domestic structures 30 or 60 minutes is normal, however, under extreme conditions and in commercial buildings, 90 minutes may be required.
The risk factors that affect the required fire resistance include:
Fire severity
The assumed fire severity can vary depending on building use and its contents. This also concerns the amount of combustible materials per unit of floor area.
Occupants
Reflects the ease at which the buildings’ occupants can be evacuated. Quantity of occupants, their health (hospitals and care homes) and residential occupants can all factor in the evacuation time.
Building height
This is the height of the top floor above ground, which will affect the ease of escape. Basements with a lack of ventilation, which may increase heat build-up, can affect the severity of fire. Once the potential fire risk has been
analysed, the ceiling is built to the requirements specified. This ceiling specification determines plasterboard
thickness and joist spacing, which relates directly to the time the ceiling can withstand fire before collapse.
Installation of a recessed downlight requires a hole to be cut into the ceiling, which will compromise the ceiling’s fire integrity and significantly decrease the time it takes for a fire to spread.
In line with Part B Building Regulations, downlights need to have the ability to maintain the fire rating of the ceiling to 30, 60 or 90 minutes.
Does it do all three?
A fire rated downlight from a reputable UK manufacturer will state a fire rating of ‘30, 60 and 90 minutes’, indicating the product has passed testing and is suitable for installation in all three ceiling types. However, since cheaper imports have become more accessible, we’re seeing an influx of product that doesn’t meet the same level of fire protection.
If a manufacturer claims the product is ‘suitable’ for use in 90 minute ceilings, this doesn’t necessarily mean it has passed testing for 30 or 60 minutes, resulting in an installation that may not meet the required level of fire protection.
To be confident about your choice of fire rated downlights, you can always ask the manufacturer for the test results to check the products passed for all three ceiling types.
At JCC we test our fire rated downlights to BS476-21 at an accredited independent testing facility as well as testing
to 30, 60 and 90 minutes, ensuring installation is safe and meets necessary requirements in all ceiling types.
