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Ensuring Compliant Fire-Rated Downlights

The rules around recessed lights are complex and the result is that not all products on the market are truly compliant. Here, Anthony Parkinson, Technical Manager at Ansell Lighting, offers advice to ensure you select the correct fire rated downlight for the right ceiling type in your facility.

Electrical Safety First, the UK’s leading charity on fire safety, recommends that fire rated downlights (FRDs) are installed in any ceilings where recessed lights are specified.

This is obviously sound health and safety advice - FRDs have in-built protection that prevents fire and heat spreading in the event of a blaze - and any facilities manager should be trusted to take it on board when overseeing work.

However, the regulations relating to recessed lights can be complex and misunderstood.

The three fire resistance ratings, of 30, 60 and 90 minutes - which indicate the length of time a complete floor-ceiling structure must be able to withstand fire to enable the evacuation of people and prevent the rapid spread of flames and heat - differ according to the building structure and number of floors. For example, if a structure has a 90 minute rating that does not mean it is automatically covered for a 30 or 60 minute rating.

Additionally, there are distinct specifications of ceiling thickness and joist spacing according to each time category, and these vary according to the different types of joists in use. Therefore, understanding a building’s fire resistance ratings and the specific requirements relating to different types of ceiling joist is essential when specifying downlights.

Posi Joist

For facilities managers overseeing work which involves the installation of recessed lighting, the key joist to be aware of is the Posi Joist. This relatively new joist combines the lightness of timber with the strength of the Posi Strut steel web, which enables it to span far greater distances. It can be used across a wide range of applications, for both floor and roof, in industrial and commercial applications. It is not used in 90 minute construction applications.

Specifications for fire resistance rating categories are:

30 minute construction –

• 600mm joist centres
• PS9 (225mm x 0.9mm) + TR26 (47mm x 72mm timber)
• 15mm Type A Wallboard plasterboard

60 minute construction –

• 600mm joist centres
• PS10 (253mm x 0.9mm) + TR26 (47mm x 72mm timber)
• 2 x 15mm Type F Fireline plasterboard

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Solid Timber Joist

It is worth being aware of this most traditional solid timber joist which, although typically seen in older domestic dwellings, is sometimes used within internal floor and separating constructions for commercial applications.

Specifications for fire resistance rating categories are:

30 minute construction –

• 600mm joist centres
• 220mm x 63mm
• 15mm Type A wallboard and plasterboard

60 minute construction –

• 600mm joist centres
• 220mm x 63mm
• 2 x 15mm Type F Fireline plasterboard

90 minute construction –

• 450mm joist centres
• 220mm x 63mm
• 2 x 15 mm Type F Fireline plasterboard

Ensuring Compliance

Selecting the right FRD can be made simple by selecting a model which complies with every category of the joist specifications and every fire resistance rating, and which come with full documentation of relevant testing, including test house certification numbers,

They also meet the requirements of Part B Fire Safety, Part C Moisture Protection, Part E Acoustic Resistance and Part L (One and Two) Energy Efficiency Building Regulations.

When specifying any FRD, request proof of certification from the lighting manufacturer, to avoid inaccurate specification or the risk of purchasing cheaper non-compliant imports.

Responsibility for fire safety in buildings is, ultimately, a collective concern. Sharing knowledge to ensure best practice and compliance with the often complex requirements associated with building construction and lighting installation can only benefit us all.