Fire Ratings for Wall Panel Materials: Class A, Class B, and What to Check Before Specifying
Why fire rating matters for wall panels
Wall cladding is one of the construction elements most closely regulated for fire performance. It occupies a large surface area in a building, it's adjacent to ignition sources in some applications, and in a fire event it can significantly accelerate or retard the spread of flame and smoke. Getting the specification wrong has serious consequences - not just during a fire, but in building regulations compliance, insurance validity, and liability.
Understanding the EU fire classification system and knowing what to check when specifying wall panels prevents these errors.
The EU classification system (EN 13501-1)
Construction products in Europe are classified for fire performance under EN 13501-1. The main reaction-to-fire classes are:
- A1 - Non-combustible. Will not contribute to a fire under any conditions. Stone, concrete, and metal products typically achieve this class
- A2 - Non-combustible with very limited combustibility. Products that contribute negligibly to fire load under fully developed fire conditions. Some MCM products and treated wood composites can achieve A2
- B - Very limited contribution to fire spread. The minimum class for most commercial wall cladding specifications. Good fire-treated wood products and quality MCM can achieve Class B
- C - Limited contribution to fire spread. Acceptable for some lower-risk commercial applications
- D, E - Higher contribution. Generally limited to residential applications in some member states
- F - No performance determined. Not acceptable for regulated applications
In addition to the main class, ratings include a suffix for smoke production (s1, s2, s3) and flaming droplets (d0, d1, d2). For most wall panel specifications, s1,d0 is the required smoke and droplet performance - meaning minimal smoke and no flaming droplets that could ignite materials below the panel.
Typical fire ratings by material type
Natural untreated wood: Class D or Class E. Not suitable for most commercial wall applications without fire-retardant treatment.
Fire-retardant treated timber: Class B-s1,d0 is achievable with appropriate treatment. The specific product and treatment method determine the class - it cannot be assumed from the species or treatment type alone. A test certificate is required.
MCM flexible tiles (quality products): Class B-s1,d0 or Class A2-s1,d0 depending on the specific product formulation. The polymer content affects fire behaviour - check the specific product certificate, don't assume from the MCM category.
PET felt: Standard PET felt typically achieves Class C or Class E. Fire-treated PET felt can reach Class B. For commercial applications, confirm the specific rating of the product being specified.
Stone wool and glass wool: Class A1 non-combustible.
What the certificate should show
When asking a supplier for fire certification, the document you receive should be a test report issued by a notified body (an EU-approved testing laboratory), and it should specify: the product name and exact construction tested, the substrate it was tested on, the achieved EN 13501-1 class, and the date of testing. The certificate should correspond to the specific product you are buying, not a similar product or a related range.
If a supplier can't provide this documentation, treat the product as unclassified for regulatory purposes.
Which fire class does your project require?
Requirements vary by building type, application location within the building, national building regulations, and project-specific risk assessments. As a general guide:
Escape routes (corridors, stairwells): Class B minimum in most European member states, Class A2 required in some high-rise or high-occupancy applications.
Public assembly areas (hotel lobbies, restaurants, theatres): Class B-s1,d0 commonly required.
Individual offices, private residences: Requirements are generally less stringent. Some residential applications have no mandatory fire class for internal wall cladding, though higher performance is always preferable.
Always confirm requirements with the local building authority or a qualified fire engineer for the specific project before finalising the specification.
