EN ISO 12215-2:2018 PDF

Overview

EN ISO 12215-2:2018 (Small craft - Hull construction and scantlings - Part 2) specifies requirements for core materials for sandwich construction and embedded materials (inserts) used in small craft hulls and structures. It applies to small craft with a hull length (LH) up to 24 m (per ISO 8666). This European adoption of ISO 12215-2:2002 sets material selection, compatibility and documentation expectations to ensure long‑term structural performance in a marine environment.

Key topics and technical requirements

• Scope and applicability
  • Focused on core materials used structurally in sandwich panels and embedded inserts for small craft (LH ≤ 24 m).
• Core material performance
  • Materials must enable the sandwich structure to meet the design loads and service life expectations defined in ISO 12215-5 (design pressures, stresses, scantlings).
  • Fatigue performance and stable mechanical properties under marine conditions are required.
  • Core materials must be able to transfer shear loads specified in Part 5.
• Material-specific rules
  • Expanded foams: must be closed‑cell type; PVC and SAN foams for primary hull/deck use must meet at least Grade I (see Table A.1). Other uses require Grade II properties.
  • End‑grain balsa: must be homogenized, free from degrading organisms, and packaged at 12–15% moisture; mechanical properties to comply with Grade I or II (see Table A.2).
  • Other cores: permitted if they meet the general structural and durability requirements.
• Embedded materials / inserts
  • Thermal expansion/contraction of inserts should be similar to the surrounding laminate.
  • Embedded plywood must be waterproof and bondable to resin; solid timber inserts are discouraged.
• Material compatibility and protection
  • Resin systems, sheathing or coatings must be compatible with the core surface.
  • Core materials should limit water penetration beyond damaged skin areas (exceptions for certain open 3D cores).
• Documentation
  • Core manufacturers must supply written properties, temperature limits and application guidance; boatbuilders must retain this data in the technical file.