Fibre Reinforced Facade Encyclopedia: Testing and standards
EN 13501-1 is the European standard that classifies construction products by their reaction to fire, from A1 (non-combustible) to F (no performance determined), with sub-classes for smoke production (s1, s2, s3) and flaming droplets (d0, d1, d2). A classification such as A2-s1,d0 or B-s2,d0 summarises the results of up to four tests and is the fire credential architects in the UK, the EU, the Middle East and much of Asia ask for first.
B-s2,d0 reads as: Class B for fire contribution (the best a polymer composite normally achieves), s2 for medium smoke production, d0 for no flaming droplets within 600 seconds. A2-s1,d0 is the minimum for external walls of relevant buildings in the UK.
At a glance
| Property | Typical value | Note |
|---|---|---|
| A1 | Non-combustible, no contribution to fire | EN ISO 1182 and EN ISO 1716 |
| A2 | Limited combustibility, negligible contribution | EN ISO 1182 or EN ISO 1716, plus EN 13823 (SBI) |
| B | Very limited contribution | EN 13823 (SBI) plus EN ISO 11925-2 |
| C | Limited contribution | EN 13823 plus EN ISO 11925-2 |
| D | Acceptable contribution | EN 13823 plus EN ISO 11925-2 |
| E | Acceptable reaction to small flame | EN ISO 11925-2 only |
| F | No performance determined or fails E | |
| s1 / s2 / s3 | Low / medium / high smoke | SMOGRA and total smoke production in the SBI test |
| d0 / d1 / d2 | No droplets / droplets under 10 s / droplets over 10 s | Flaming droplets in the SBI test |
The tests behind the classes
Class A1 and A2 depend on the non-combustibility furnace test EN ISO 1182 and the gross calorific value test EN ISO 1716. Classes A2 to D are decided by the single burning item test EN 13823, in which two boards form a corner and a 30 kW burner runs against the joint for 20 minutes while heat release, smoke and droplets are measured. Classes B to E also need the small flame test EN ISO 11925-2. The thresholds are numerical: for Class B the fire growth rate index must not exceed 120 W/s and the total heat released in the first 600 seconds must not exceed 7.5 MJ; Class C allows 250 W/s and 15 MJ; Class D 750 W/s.
How the classes are used
In the UK, Approved Document B and the 2018 ban on combustible materials require A2-s1,d0 or better for products in the external walls of relevant buildings above 18 metres, with limited exemptions. Ireland, the UAE Civil Defence code, Singapore’s SCDF Fire Code and Hong Kong’s Buildings Department all accept or require EN 13501-1 classes for external cladding, generally at A2-s1,d0 or A1 for the cladding material and with a full-scale test for the assembly. In the EU the class is declared through the CE mark under the Construction Products Regulation and each member state sets the required class by building type and height.
Reading a classification report
The classification report names the product, the thickness, the substrate and the mounting and fixing used in the test. A class earned on a 10 mm laminate on a calcium silicate board does not automatically cover a 5 mm laminate on a different backing. Extended application rules exist but must be stated in the report. Ask for the classification report, not a summary certificate, and check the field of application before relying on it.
Where fibre reinforced composites sit
GRC and GRG products, being cementitious or gypsum based, can be tested for Class A1 or A2. FRP products, with a polymer matrix, are classified from B downward; Class B with s1 or s2 and d0 is the target for an architectural FRP panel and requires a fire retardant resin system and careful laminate design. ShapeShell-RT is classified B-s2,d0 by Intertek on a 10 mm laminated panel.
Standards and references
- EN 13501-1 Fire classification of construction products and building elements, Part 1: Classification using data from reaction to fire tests
- EN ISO 1182 (non-combustibility), EN ISO 1716 (gross heat of combustion), EN 13823 (single burning item), EN ISO 11925-2 (single flame source)
- Approved Document B and Building Regulations Regulation 7(2) (England); Building (Scotland) Regulations
- UAE Fire and Life Safety Code of Practice; SCDF Fire Code (Singapore); Code of Practice for Fire Safety in Buildings (Hong Kong)
- Construction Products Regulation (EU) 305/2011
Open the fire standards atlas to see how EN classes line up with Australian tests.
Related terms
Questions specifiers ask
What does B-s2,d0 mean?
Class B for contribution to fire, the best class a polymer composite usually reaches; s2 for medium smoke production; d0 for no flaming droplets in the first 600 seconds of the SBI test.
What class is required for cladding in the UK?
For the external walls of relevant buildings above 18 metres, A2-s1,d0 or better, under the 2018 combustible materials ban. Lower buildings follow Approved Document B, which allows other routes including BS 8414 testing.
Is Class A1 the same as non-combustible?
Yes in substance. A1 is achieved by passing EN ISO 1182 and EN ISO 1716 with tight limits and is the European expression of non-combustibility. A2 is limited combustibility with slightly relaxed limits.
What EN 13501-1 class does ShapeShell-RT hold?
B-s2,d0, classified by Intertek Testing Services on a 10 mm laminated panel. Full details are on the ShapeShift fire rating page.
Can an EN 13501-1 class be used for NCC compliance in Australia?
Not directly. The NCC references AS 1530.1, AS 5637.1 and AS 5113. A European classification is useful supporting evidence for a Performance Solution but does not replace the Australian tests.
ShapeShell-RT: EN 13501-1 B-s2,d0 (Intertek). ShapeShell-RC: non-combustible to AS/NZS 1530.1. See every result in one table. See ShapeShell fire test data
Reviewed by Richard Halvorsen, General Manager, ShapeShift Technologies. Last updated September 2026.