EN 1090 EXC3 Explained: The Gold Standard for Structural Steel
Deep dive into EN 1090 Execution Classes. What separates EXC3 from EXC2, certification requirements, and why it matters for DACH procurement.
What is EN 1090?
EN 1090 is the harmonized European standard for the fabrication and assembly of steel and aluminium structures. It is mandatory for any structural steel product bearing the CE mark within the European Economic Area.
The standard defines four Execution Classes (EXC1 to EXC4), each demanding increasingly rigorous quality controls, weld inspections, and material traceability.
Execution Class Pyramid
EXC2 vs. EXC3: The Critical Difference
| Requirement | EXC2 | EXC3 |
|---|---|---|
| Welding inspection | 10% NDT | 100% NDT |
| Material traceability | Batch level | Individual piece |
| Weld procedure tests (WPQR) | Basic | Full qualification |
| Surface preparation | Sa 2 | Sa 2½ min. |
| TÜV audit frequency | Annual | Bi-annual + unannounced |
| CE DoP documentation | Standard | Extended + As-Built |
Why EXC3 Matters for DACH
German, Austrian, and Swiss building authorities (Bauaufsicht) routinely require EXC3 for any structure classified as Consequence Class CC2 or higher — which includes industrial halls, telecom towers, and power infrastructure.
Industrial Halls
Halls with overhead cranes or public access → EXC3 mandatory
Telecom Towers
Any structure >20m height in public space → EXC3 minimum
Power Infrastructure
HV transmission towers → EXC3 or EXC4 depending on voltage
Architectural Steel
AESS visible structures in public buildings → EXC3 with enhanced finish
Steel-Hub.eu Certification Stack
- ✓EN 1090-2 EXC3 — TÜV-certified factory production control
- ✓ISO 3834-2 — Comprehensive welding quality management
- ✓ISO 1461 — Hot-dip galvanizing for corrosion protection
- ✓100% NDT — Ultrasonic + magnetic particle testing on all critical welds
- ✓EN 10204 3.1 — Individual material certificates for full traceability