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Fire Rated Decking: What’s the difference between A1 and A2 fire rating?

Alfresco Floors | What is the difference between A1 and A2 fire rating?

Fire Rated Decking: What’s the difference between A1 and A2 fire rating?

Alfresco Floors | What is the difference between A1 and A2 fire rating?

This article was originally written in 2020. For a more contemporary look at Class A fire ratings, and how that affects your fire-rated decking, you should read this article. You can also find a more up-to-date breakdown of balcony flooring fire regulations here.

In the UK, building regulations state that any high-rise building above 18 metres (which is potentially being changed to 11 metres), should not have combustible materials within the construction of external walls and specified attachments.

This means that on such buildings, only fire-rated decking with an A1 or A2 fire rating can be used – by law.

This blog sets out to explore the Euroclass system for fire rating, whilst focussing on the characterises of A1 and A2 rated materials.  


Non-Combustible Decking: Balcony Flooring Fire Regulations Explained

Before exploring Class A1 and A2 in-depth, it’s important to understand the fire regulations and process of fire testing. This is in order for products to pass British Standard tests regarding fire protection, regulation and the subsequent Euroclass rating that the product receives once tested. Once completed this helps your decking be determined as fire-rated decking.

The classification system is defined in BS EN 12501-1. It is recognised as the primary standard within the construction industry and involves a combination of up to five rigorous tests. These tests are designed to assess a product on a range of characteristics including heat levels, combustibility, flame spread and smoke release.

Once tested, the product receives an official classification of its fire rating – known as a Euroclass rating. This information is of great use to specifiers and contractors to determine the best fire-rated decking options for their needs.

Fire Rated & Non-Combustible Decking: The Three Fire Rating Classifications

The BS EN 13501-1 classification comprises three fire ratings.

1. Euroclass Rating

The first is the Euroclass Rating and the subsequent abbreviations are as follows:

  • Euroclass rating – which will be the letter A1, A2, B, C, D, E or F
  • Flooring materials are followed by the abbreviation ‘fl’ (e.g A1fl)
  • Linear pipe thermal insulation products are followed by the abbreviation ‘L’ (e.g. A1L)

2. Smoke Emission During Combustion

The second classification relates to smoke emission during combustion. This is indicated by an s1, s2 or s3 rating – from highest to lowest performance. It’s important to note that smoke emission classifications are not provided for products with an E or F rating.

3. Production of flaming droplets/particles

This rating is indicated by d0, d1 or d2 from highest to lowest performance. E-rated products receive a d2 flaming droplet classification.

It’s important to note that A1-rated products aren’t given a smoke emission or flaming droplet rating. This is based on the assumption that they make no contribution to fire growth or spread.


A1 and A2 Fire-Rated Decking Materials

When materials are given an A1 or A2 fire rating, it essentially gives them the ‘non-combustible’ seal of approval – meaning that materials with such ratings can be specified for use on high rise developments above 18 metres (potentially soon to be 11 metres).

The most stringent tests – as highlighted above – must be passed in order for construction products to reach a Class A rating.

As we’re aware, A1 rated products – which have been manufactured with materials highlighted Commission Decision 96/603/EC – do not require additional fire safety tests. Examples of these include aluminium, natural stone, concrete and porcelain.

However, these materials are only ‘naturally A-rated‘ if they haven’t been treated in any way. For example, applying a powder coating to aluminium may affect the fire performance rating.

Below is a table to demonstrate the testing criteria which grants materials with an A2 rating.

Fire Rated Decking For Your Projects

As specialists in class A fire-rated decking, Alfresco Floors is more than happy to help aid the specification with your next project. Explore our case studies [insert link] to view some of our most recent projects and be sure to download our latest guide to fire regulations.

For more information on how you can achieve compliance with your next project, call us on 020 8977 0904, fill out the form below or get in touch with our expert team today.