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Fire rating classifications: understanding the A1 rating for masonry
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Learn more about the fire ratings for concrete blocks and what they signify in our helpful article.
Understanding fire rating classifications is crucial for ensuring the safety and resilience of buildings in the event of a fire.
These classifications, established through rigorous testing and standards, provide essential information about how materials behave when exposed to fire. From the highest level of non-combustibility to materials that allow minimal flame spread, fire ratings guide architects, builders and specifiers when selecting appropriate construction products.
In this article, we’ll take a closer look at fire rating classifications, explaining what they mean and how they were developed.
What are the fire rating classifications for masonry?
When it comes to fire, concrete blockwork performs well due to its inherent fire resistance. Concrete blocks therefore have the highest fire resistance classification (class A1) under BS EN 13501-1.
BS EN 13501-1 specifies the method of fire classification for construction products and building elements. Materials that are classified as A1 are non-combustible and satisfy the requirements of all other classifications. This classification was defined by the European Commission, which means it isn’t necessary to test concrete to demonstrate this fire rating. The decision can be applied to all concrete blocks with less than 1% volume or weight of organic material.
The grades of fire rating
The seven grades of fire rating are as follows:
- A1: Materials do not contribute to a fire at any stage. No further classification is needed.
- A2: Materials do not contribute to a fire, but they do have the potential to make smoke or flaming droplets. Further classification for these effects is therefore needed for A2 materials.
- B: The material is highly resistant but you will need further classification for potential smoke and/or flaming droplets.
- C: These materials have limited contribution towards fire.
- D: A material can contribute towards a fire, but it has greater resistance than materials that fall into category E.
- E: Materials have a significant contribution towards fire but can resist a small flame for a short period of time.
- F: This is reserved for untested products or combustible materials that have failed to meet the other ratings.
Understanding the A1 fire rating
What does an A1 fire rating mean?
An A1 fire classification is the highest classification in terms of fire exposure. It means that a material is non-combustible and will not contribute to the spread of fire.
Materials that achieve an A1 rating do not ignite, produce no smoke and do not emit flaming droplets when exposed to fire. This rating is determined through careful testing and is essential for ensuring maximum safety in building construction, particularly in areas where the fire risk is significant.
A class A1 rated wall is therefore constructed using materials that offer maximum fire protection.
For specific applications, the requirements for determining the appropriate fire classification is given in Approved Document B to the Building regulations.
Materials that are A1 fire rated
Building materials that are A1 fire rated include:
- Concrete, including concrete blocks
- Natural stone
- Aluminium (provided it is untreated)
- Porcelain
- Clay bricksÂ
What's the difference between an A1 and A2 rating?
An A1 rating represents the highest level of fire resistance. It signifies that the material is completely non-combustible and will not ignite, produce smoke or emit flaming droplets when exposed to fire.
An A2 fire rating also indicates a high level of fire resistance but signifies that the material could create smoke or flaming droplets. This means that these effects will have to be further investigated.
Essentially, A1 materials provide the utmost safety by being entirely non-combustible, while materials with A2 fire ratings offer robust fire resistance with minimal combustibility.
A1 fire rated concrete blocks
Concrete blocks, including all of our products, are A1 fire rated. This makes them a highly reliable material when it comes to meeting requirements for reactions to fire.
Find out more about our blocks
If you’re looking for the right concrete block for your next building project, then please get in touch. Our helpful Lignacite Quoting Team will be able to help you find the right product.
Call us on 01842 778485 today.
