26 May What’s the difference between A1 and A2 fire rating?
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 materials 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.
Fire Regulations Explained
Before exploring class A1 and A2 in-depth, it’s important to understand the process of fire testing in order for products to pass British Standard tests regarding fire protection – and the subsequent Euroclass rating that the product receives once tested.
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 solutions available for their needs.
An Overview Of Fire Classifications: Three Ratings
The BS EN 13501-1 classification comprises three ratings.
The first is the Euroclass Rating and the subsequent abbreviations 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 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.
As specialists in class A fire-rated solutions, 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 or fill out the form below and an expert will be in touch.