One of the most important aspects of considering which materials to use when insulating a building is how it will perform against the possibility of a fire.
Insulation products need to pass several tests related to fire protection in order to be used in the UK, with these tests using contractors and specifiers to determine the best fire-rated insulation that is available for their needs.
The main classification system that is used in the current day is the BS EN 13501-1, which combines five active tests to determine whether the material is fit for purpose. They look at the likes of flame spread, smoke release, heat levels and combustibility.
After the tests are fully conducted, the material is then given an official fire rating classification, which is also known as a Euroclass rating.
Insulation Express sell a range of excellent fire-resistant insulation products to help with your construction and insulation tasks.
Fire-rated insulation classifications: what are they?
Euroclass rating
Euroclass ratings are given via letters to outline their fire performance level, ranging from A1 to F. A1 is the highest performance level, with F as the lowest.
Each rating also has a definition classification attached, such as ‘Combustible’, ‘Limited Combustibility’ or ‘Non-Combustible’.
| Classification |
Definition |
Meaning |
| A1 |
Non-Combustible |
No contribution to fire |
| A2 |
Limited Combustibility |
Very limited contribution to fire |
| B |
Combustible |
Limited contribution to fire |
| C |
Combustible |
Minor contribution to fire |
| D |
Combustible |
Medium contribution to fire |
| E |
Combustible |
High contribution to fire |
| F |
Combustible |
Easily Flammable |
If flooring materials are used, they are followed by the abbreviation ‘fl’, for example, Cfl. If linear pipe thermal insulation products are being used, they are followed by the abbreviation ‘L’, such as CL.
These ratings are taken from the current European standards and are generalised definitions, while Insulation Express simply pass on the information as it is given and cannot be held responsible for any misinterpretation.
Smoke Emission
Another listed classification relates to the smoke emission amounts during combustion, with ratings of S1, S2 and S3 given, with S1 being the highest performance and S3 being the lowest.
These classifications are not provided for any products that are given an E or F rating.
| Classification |
Meaning |
| S1 |
Speed and quantity of smoke emissions are absent or weak |
| S2 |
Speed and quantity of smoke emissions are of average intensity |
| S3 |
Speed and quantity of smoke emissions are of high-intensity |
Flaming droplets during combustion
The final classification level relates to the level of production of flaming droplets and particles during a fire. They are provided with a rating of either D0, D1 or D2, with D0 being the highest performance and D2 being the lowest.
Any F-rated products don’t receive one of the above classifications, while A1 rated products don’t get either a smoke emission or flaming droplet classification as they make no contribution to the spread of a fire.
| Classification |
Meaning |
| D0 |
No dripping |
| D1 |
Low dripping |
| D2 |
High dripping |
Non-combustible insulation
Any non-combustible insulation materials are the best option when looking at fire protection products. These materials can only be classified officially as non-combustible if it is given an A1 Euroclass rating.
Some examples of non-combustible materials include glass wool, rock wool, cement and glass foam.
There are some great examples of non-combustible materials available to buy from Insulation Express, including Versaroc Fibre Cement Board.
Which are the best products for fire resistance?
Mineral wool and fibreglass products are often the best options when looking for fire resistance. To help prevent the spread of fire and smoke in hidden spaces, the Rockwool Fire Barrier is an excellent option as it provides fire resistance for up to 1 hour, while also being quick and easy to install.
