Overview - EN ISO 12944-3:2017 (Design considerations)
EN ISO 12944-3:2017 is Part 3 of the ISO 12944 series on corrosion protection of steel structures by protective paint systems. It defines basic design criteria for steel structures to be coated, with the objective of avoiding premature corrosion and degradation of coatings or the substrate. The standard gives practical examples of appropriate and inappropriate design and explains how to minimize problems during application, inspection and maintenance. It also addresses design measures that facilitate handling, transport and erection.
Key topics and technical requirements
The standard focuses on practical design measures that affect corrosion protection and coating performance, including:
- Accessibility for surface preparation, coating application and inspection (annexes provide typical tool clearance and opening sizes).
- Treatment of gaps and sealed joints to prevent ingress of moisture and contamination; requirements for gap sealing materials are included.
- Prevention of water and deposit retention, with design guidance to avoid troughs, ledges and cavities that trap moisture.
- Surface imperfections - treatment of welds, edges and notches to ensure adequate surface preparation and coating adhesion.
- Bolted connections - detailing for slip-resistant and preloaded connections, and selection/ protection of bolts, nuts and washers to reduce corrosion risk.
- Box members and hollow components - design for adequate access, venting and drainage to enable internal coating and inspection.
- Galvanic corrosion prevention - design advice to avoid dissimilar-metal contact creating galvanic couples.
- Handling, transport and erection - recommendations to reduce damage to coatings and expose fewer vulnerable details during logistics.
Informative annexes provide guidance on minimum dimensions for access openings, narrow spaces and radii, plus examples of design features that avoid water retention.
Practical applications
EN ISO 12944-3 is used to:
- Integrate corrosion-aware design into structural drawings and specifications.
- Reduce lifetime maintenance and coating failures by design.
- Improve safety and quality of surface preparation, coating application and inspection processes.
- Facilitate efficient fabrication, transport and on-site erection with minimal coating damage.
Who should use this standard
- Structural and corrosion engineers
- Design offices and detailers of steelwork
- Fabricators and manufacturers of steel components
- Coating contractors and applicators
- Inspection bodies, specifiers and asset owners
- Procurement and maintenance planners
Related standards
EN ISO 12944-3:2017 is part of the ISO 12944 series and references other standards such as:
Using EN ISO 12944-3 early in the design process reduces corrosion risk, lowers lifecycle costs and simplifies coating application and maintenance.
