A fire rated downlight re-establishes the fire barrier provided by the ceiling after the hole is cut. Once the hole is cut this is an area of weakness and so a product needs to be used that retains the fire rating of the ceiling. When a hole is cut into a ceiling to accommodate the downlight, this in turn creates a fire hazard as it compromises the fire barrier of the ceiling allowing an area of weakness for the fire to move through.
Regulations ensure that downlights used in ceilings minimise the risk of fires spreading from one floor to another of a building and fire rated downlights help to slow down the spread of a fire if one was to occur.
There are two ways a downlight can protect the integrity of the ceiling, it can either use an intumescent material or a borosilicate glass. Just as equally important to the material used, is the downlight can and the springs in the light fixture. If these were to fail and not hold in the event of a fire, this in turn will prevent the intumescent or borosilicate glass to perform its job in preventing the fire travelling through the void and to the floor above.
Ansell's Fire Rated downlights are fitted with an intumescent pad which, when there is a fire, the heat causes the pad to swell and expand within the fixture and helps slow the spread of the fire. Ansells range of fire rated downlights can be covered with continuous mineral wool insulation, however the driver should remain in free air space to avoid overheating.
Part B (Fire Safety)
This Fire Safety regulation, addresses the precautionary measures necessary to provide safety from fires for building occupants, persons in the vicinity of buildings, and firefighters. Typically ceilings are rated for 30, 60 or 90 minutes for each particular ceiling type.
Part L (Energy Efficiency)
This relates to the energy performance of new and existing buildings, ensuring Ansell products meet the required energy efficiency levels.
Part C (Resistance to Contaminants and Moisture)
This regulation ensures the prevention of moisture or contaminants passing through a downlight into voids.
Part E (Resistance to Sound)
This protects the resistance to the passage of sound and sound insulation from appliances in the home.
The National House Building Council (NHBC) stipulates that fire rated downlights are used on all new build dwellings. These downlights must comply with either 30, 60 or 90 minute rating depending on where they are placed within a dwelling. NHBC regulations state that dwellings with the height of the top floor above ground level being below 5m, require 30 minute rated downlights. Dwellings with a maximum top floor height of 18m 60 minute rated downlights and those below 30m require 90 minute downlights. Dwellings which exceed 30m above ground level, high rise flats for example, require 120 minute rated downlights, the highest rating available.
Those dwellings, usually high-rise flats which have underground car parks, which have a basement that is 10m or less below ground level must be installed with fire rated downlights which have a rating of 60 minutes. Those basements which exceed 10m, must be installed with 90 minute downlights.
A regulation change in the industry was instigated by the National House Building Council in August 2019 and implemented in January 2020. This change amended an outdated 30 min specification not covering 3 storey single dwelling homes. The 30 minutes specification covers dwellings up to 5M and now has the addition of 3 storey dwellings.
Fire tests are carried out to ensure that the downlights used in building constructions conform to regulations and maintain the integrity of the ceiling in the event of a fire.
The solid timber joist is the traditional ceiling joist used and typically is only found in domestic dwellings already constructed. They are widely used within internal floor and separating construction, for both residential and commercial applications.
I-Joist are used on new build dwellings throughout the UK and is a lightweight joist inclined for domestic applications. I-Joist are now dominant in the housing market and continue to grow in popularity as they have a greater strength to weight ratio compared with other options.
Metal Web or Posi-Joist, as its it sometimes called, is a new joist type used in the UK. Posi-Joist combines the lightness of timber with the strength of the Posi-Strut steel web allowing you to span far greater distances. This joist type can be used across a wide range of applications for both floor and roof in domestic, industrial and commercial applications.