An A2 class (GB 8624) is the single most consequential line on a cladding specification — and the easiest to fake. Across Europe, the Gulf and much of Asia, post-Grenfell regulations now require non-combustible cladding above defined building heights. That requirement turned “A2” from a technical detail into a procurement gate, and wherever a compliance gate appears, certificate fraud follows.
This guide is about verification, not material science. For the underlying fire performance of MCM flexible stone, see our MCM fire rating guide. Here we cover how to read a classification report, what has to be on it, and the specific patterns that indicate a document will not survive review.
What “A2” Actually Means
Under EN 13501-1, the harmonised European reaction-to-fire standard, construction products are classified A1 through F. Each class carries two suffixes:
- Smoke production — s1 (absent or weak), s2 (average), s3 (strong)
- Flaming droplets — d0 (none), d1 (slow droplets), d2 (fast droplets)
So the full classification is A2-s1, d0: limited combustible contribution, minimal smoke, no flaming droplets. A2 sits directly below A1 (fully non-combustible). For a mineral-based cladding panel, A2 is the practical ceiling.
The distinction matters commercially. A supplier quoting plain “A2” without the s and d suffixes is omitting half the classification. A2-s2, d2 and A2-s1, d0 are not the same product in the eyes of a building control officer.
The Three Systems You Will Meet
| System | Region | Equivalent top class | What it measures |
|---|---|---|---|
| EN 13501-1 | Europe, widely adopted elsewhere | A2-s1, d0 | Reaction to fire, smoke, droplets |
| ASTM E84 | United States | Class A (FSI < 25) | Flame spread and smoke developed index |
| GB 8624 | China | A2 | Combustion performance, aligned with EN tiers |
MCM flexible stone is tested under all three. The ASTM E84 result is Class A with a flame spread index well below the 25 threshold, which qualifies the material for the most demanding interior locations including exit stairways and corridors. GB 8624 (2012 revision, harmonised with EN 13501-1) yields an A2 grade.
Regional codes layer requirements on top of these classifications. Our USA guide covers ASTM and IBC provisions; the Europe guide covers CE marking under the Construction Products Regulation; and our UAE, Saudi Arabia and Qatar guides cover Gulf civil defence requirements.
How to Read a Classification Report
A classification report is not a test report. This distinction trips up a lot of buyers.
- Test report — raw results from a specific laboratory run on a specific sample. It records what happened in the apparatus.
- Classification report — a formal document that maps those results onto the EN 13501-1 classes. This is the document a building control authority wants.
A supplier who can only produce a test report has not demonstrated a classification. Ask for the classification report.
Seven things that must be present
- Notified Body identification. In Europe, classification for CE marking purposes must come from a Notified Body — organisations such as Efectis, Warringtonfire or equivalent. The report should carry the body’s name and notified number.
- Standard and date. “EN 13501-1” plus the year of the standard applied.
- Full classification string. A2-s1, d0 — not just “A2”.
- Product identification. Manufacturer, product name, and enough description to tie the report to the exact panel you are buying. Generic reports for “flexible stone panels” that do not name your product are worthless.
- Mounting and substrate conditions. Fire performance depends on what the panel is bonded to and how it is fixed. The report must state the tested assembly.
- Thickness range covered. A classification tested at 3 mm does not automatically extend to 8 mm. Check that the approved range brackets your specified thickness.
- Report number and date. Classifications are not eternal. Check validity.
Red Flags
These patterns indicate a document that will fail review — or worse, pass review and fail later:
- No Notified Body. An “in-house” or unnamed-laboratory classification is not acceptable for CE marking.
- Suffixes missing. “A2” without s and d values.
- Product mismatch. The report names a different product line, thickness or manufacturer than the one quoted.
- Scan with no verifiable number. A PDF with the report number redacted or cropped cannot be checked with the issuing body.
- Polymer binder with an A2 claim. Panels relying on polyurethane, epoxy or acrylic resins as the binder are combustible by chemistry; they realistically land at B or C. A trader claiming A2 for a resin-bound panel deserves hard scrutiny. This is why MCM uses mineral modification rather than polymer binders — see the fire rating guide for the mechanism.
- Classification without an assembly. Fire ratings belong to the installed system, not the loose panel.
The System Is What Gets Approved
This is the point most specifications get wrong. The panel’s A2 classification does not transfer to the wall automatically. Three elements have to line up:
- Adhesive. Use polymer-modified cementitious adhesives that have been tested together with the panels. Substituting an untested adhesive can compromise the assembly’s classification.
- Substrate. Concrete, cement board and similar non-combustible substrates maintain the A2 result. Applying A2 panels over a combustible substrate does not produce an A2 wall.
- Joints and penetrations. Gaps wider than 3 mm should be filled with fire-rated joint compound. Transitions, electrical penetrations and wall-to-ceiling junctions are the usual weak points.
Installation detail is covered in our step-by-step installation guide.
Where A2 Is Mandatory
Requirements differ by jurisdiction, and they change — always confirm against the current code for your project:
- United Kingdom — Building Regulations require non-combustible cladding (A2-s1, d0 or better) on residential buildings above 18 metres.
- Germany — the Hochhausrichtlinie requires non-combustible facade materials above 22 metres.
- France — Class A2 for high-rise buildings and buildings open to the public.
- Gulf states — civil defence codes require A2 or better for cladding above defined heights; see the UAE and Saudi guides.
Healthcare, education and transport facilities frequently impose A2 requirements regardless of height, because evacuation is slow or difficult. Our high-rise guide and fire rating guide cover these applications.
Verifying Before You Buy
The practical sequence:
- Request the classification report, not the brochure. Ask for the full document including annexes.
- Check the issuing body directly. Notified Bodies maintain registries; a verifiable report number is the whole point.
- Confirm the product name, thickness and tested assembly match your specification.
- Cross-check the adhesive and substrate you intend to use.
- Order 200 × 200 mm samples and test them independently if the project is fire-critical.
- Ask which standards apply to your market — our supplier and manufacturer guide sets out what a credible factory will answer without hesitation.
Request Documentation
TooFlexi supplies MCM flexible stone with classification documentation covering EN 13501-1 (A2-s1, d0), ASTM E84 (a U.S. test) and GB 8624 (A2, factory tested). Standard orders start at 200 m² per colour with 15–25 business day lead times. Request the current test documentation and a sample kit for your project, or browse the product catalogue.
