How to read EN 12467
EN 12467 is the European standard for fibre-cement flat sheets: it defines classification, requirements and test methods. The classification is based on four parameters. Below is what each of them means.
1. Type: NT or AT
NT covers sheets made with non-asbestos technology; AT contains asbestos.
2. Category: A, B, C or D
| Category | Intended conditions |
|---|---|
| A | Heat, high moisture and severe frost — external, unprotected |
| B | Heat, moisture and occasional frost — protected from severe weathering |
| C | Internal applications: heat and moisture, no frost |
| D | Rigid underlayer applications |
3. Class: 1 to 5
The class is set by the minimum bending strength (MOR). Categories A and B are specified in the wet condition, Categories C and D in ambient laboratory conditions.
| Class | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| Categories A & B, wet, MPa | 4 | 7 | 13 | 18 | 24 |
| Categories C & D, ambient, MPa | 4 | 7 | 10 | 16 | 22 |
4. Size group and tolerance level
Small size sheets have an area below 0.4 m² with a length/width ratio up to 3 and are installed with horizontal overlap; all others are large size. Two tolerance levels (I and II) apply to length, width, straightness and squareness — a sheet must meet the same level for all four.
5. Durability tests
| Test | Category A | Criterion |
|---|---|---|
| Freeze–thaw | 100 cycles | RL not less than 0.75 |
| Heat–rain | 50 cycles | no cracks, delamination or warping |
| Warm water | 56 days at 60 °C | RL not less than 0.75 |
| Soak–dry | 50 cycles | RL not less than 0.75 |
| Water impermeability | — | traces of moisture allowed, drops are not |
6. Reaction to fire — outside EN 12467
The standard does not assign a fire class; it refers to EN 13501-1. Sheets with no more than 1 % organic content are deemed to satisfy Class A1 without testing under Commission Decision 96/603/EC. Anything above that threshold must be tested and classified: Class A2 requires EN ISO 1716 and EN 13823 with a classification report.