Corrosion protection according to EN 1090 – Standards, obligations & testing processes
Corrosion protection is a key component of the standard-compliant execution of load-bearing steel and aluminum structures.
The European standard EN 1090 obliges manufacturers, coaters and processors to verify corrosion protection measures using measurement technology, to document them and to ensure their permanent implementation within the framework of factory production control (FPC).
This article explains:
- which testing obligations arise from EN 1090,
- how they are technically correctly documented,
- which standards are additionally relevant,
- which measurement technology is required (including internal product links),
- and how a complete testing process is structured in practice.
1. Testing obligations in corrosion protection according to EN 1090
EN 1090 requires manufacturers to ensure complete quality control of surface preparation and coating.
This includes in particular:
Non-delegable manufacturer obligations
- Selection of suitable coating systems according to ISO 12944
- Purity testing (ISO 8501, ISO 8502)
- Surface roughness testing (ISO 8503-5)
- Testing of wet and dry film thickness
- Pore and defect testing in thick-layer systems
- Climate and dew point testing during application
- Complete documentation of all test steps
→ Even if an external coating company is commissioned, the overall responsibility remains with the manufacturer of the structure.
2. Overview of relevant standards
The following standards play a crucial role in corrosion protection according to EN 1090:
Standard – Topic Area – Key Statements
| Norm | Themenbereich | Kernaussagen |
|---|---|---|
| EN 1090-2 | Ausführung von Stahltragwerken | Anforderungen an Fertigung, Oberflächenvorbereitung, Korrosionsschutz und werkseigene Produktionskontrolle (WPK) für tragende Stahlbauteile. |
| DIN EN ISO 12944 | Korrosionsschutz durch Beschichtungssysteme | Korrosivitätskategorien (C1–CX), Schutzdauern (L/M/H/VH) sowie Anforderungen an Beschichtungssysteme und Applikationsbedingungen. |
| ISO 8501 | Oberflächenreinheit | Visuelle Reinheitsgrade gestrahlter Stahloberflächen (z. B. Sa 2½) als Grundlage für Beschichtungen. |
| ISO 8502-4 | Klima und Taupunkt | Messung von Lufttemperatur, Oberflächentemperatur, relativer Luftfeuchte und Taupunkt während Beschichtungsarbeiten. |
| ISO 8503-5 | Oberflächenprofil | Bestimmung des Rauheitsprofils gestrahlter Oberflächen mittels Replica-Film. |
| ISO 4624 | Haftfestigkeit | Haftzugprüfung zur Beurteilung der Haftfestigkeit von Beschichtungen. |
| ISO 16276-1 | Schichtdickenprüfung | Statistische Verfahren zur Bewertung von Trockenschichtdicken von Beschichtungen. |
3. Corrosion protection methods and their testing requirements
Hot-dip galvanizing
- Check layer thickness
- Evaluate uniformity
- Standard: EN ISO 1461
Organic coating systems (ISO 12944)
- Check wet and dry film thickness
- Ensure pore-free operation
- Monitor climate during application
- Norm: ISO 12944-5
Thermal spraying
- Roughness profile according to ISO 8503-5
- Layer thickness
- Defect detection
→ A procedure is only compliant with standards if the associated testing processes are metrologically proven.
4. Measurement technology for all testing obligations according to EN 1090
Below you will find a structured overview of the measuring instruments required to fulfill the testing obligations.
Layer thickness measurement (wet and dry film)
Tasks:
- Ensure minimum layer thickness (ISO 12944-5)
- Document system architecture
- Archive test data
Suitable devices:
- PosiTector 6000 (metallic substrates)
- PosiTector 200 (non-metallic substrates)
- mtv Nassfilmkämme
Pore and leak testing
Tasks:
- Detecting defects, pores, and capillary cracks
- Validate protection systems
- Select high-voltage or low-voltage testing depending on the layer thickness.
Suitable devices:
- PosiTest LPD (Low Voltage)
- PosiTest HHD / Compact DC30 (High Voltage)
Roughness & surface profile measurement
Tasks:
- Ensure liability-relevant roughness
- Use replica film according to ISO 8503-5
Suitable devices:
- PosiTector RTR-H / RTR-3D
- PosiTector SPG
Climate and dew point monitoring
Tasks:
- Monitor climate during application
- Ensure compliance with the 3-K rule
Suitable devices:
- PosiTector DPM
- PosiTector DPM-L
5. Overview: Testing obligation – Standard – Measuring instrument
| Prüfpflicht | Zugehörige Norm | Typisches Messgerät |
|---|---|---|
| Überwachung der Klimabedingungen | ISO 8502-4, DIN EN ISO 12944 | Taupunktmessgerät (z. B. PosiTector DPM / DPM-L) |
| Kontrolle der Oberflächenreinheit | ISO 8501 | Visuelle Vergleichstafeln, Inspektionshilfen |
| Messung des Oberflächenprofils | ISO 8503-5 | Rauheitsmessgerät / Replica-Film (z. B. PosiTector RTR, SPG) |
| Messung der Trockenschichtdicke | EN 1090-2, ISO 16276-1 | Schichtdickenmessgerät (z. B. PosiTector 6000 / 200) |
| Nassschichtdickenkontrolle | DIN EN ISO 12944 | Nassfilmkamm oder Nassfilmrad |
| Poren- und Fehlstellenprüfung | DIN EN ISO 12944 | Porenprüfgerät (Niederspannung oder Hochspannung) |
| Prüfung der Haftfestigkeit | ISO 4624, ISO 16276-1 | Haftzugprüfgerät (z. B. PosiTest AT) |
| Dokumentation der Eigenprüfung | EN 1090-2 | Messgeräte mit Speicher- und Exportfunktion |