EN 16254:2013/FprA1:2015

Overview

EN 16254:2013/FprA1:2015 is a CEN European Standard that defines classification and performance requirements for Emulsion Polymerized Isocyanate (EPI) adhesives used in the industrial manufacture of load-bearing timber structures. The standard classifies EPI adhesives according to their suitability for specified climatic exposure conditions and sets performance requirements that apply to the adhesive itself, not to the completed timber structure. It is principally intended as a quality-assessment and control tool for adhesive manufacturers and users of timber elements bonded with EPI adhesives.

Key topics and requirements

• Scope and applicability

  • Classification of EPI adhesives for use in load-bearing timber structures under defined climate conditions.
  • Performance requirements apply only to the adhesive, not the structural performance of the finished element.
  • Focus on industrial (factory) manufacture of timber structures; on-site gluing is excluded except under factory-like conditions.
  • Excludes production of wood-based panels (except solid wood panels) and heavily modified/stabilized woods (e.g., acetylated, heat‑treated, polymer‑impregnated) with substantially reduced swelling/shrinkage.

• Classification

  • Adhesives are categorized by suitability related to environmental/climatic exposure (e.g., moisture and temperature regimes).
  • Classification supports appropriate selection of EPI adhesives for intended service conditions.

• Performance requirements

  • Specifies performance criteria that adhesives must meet to be considered suitable for load-bearing timber applications in the defined conditions.
  • Requirements are intended for quality control and conformity assessment of the adhesive product.

• Process considerations

  • An adhesive meeting EN 16254 requirements is considered adequate provided the bonding process follows an appropriate product standard and proper manufacturing controls.

Applications

• Use EN 16254 when selecting or certifying EPI adhesives for:
  • Gluing laminated beams (glulam), cross-laminated timber (CLT) components, and other factory-made load-bearing timber elements.
  • Industrial adhesive formulation, testing, and quality assurance programs.
  • Specifying adhesives for timber products that will be exposed to specific climatic conditions.

Who should use this standard

• Adhesive manufacturers developing or certifying EPI formulations.
• Timber product manufacturers (glulam, heavy timber, prefabricated elements) performing factory bonding.
• Quality managers, engineers, and specifiers responsible for adhesive selection, testing, and production control.
• Standards bodies and conformity assessors involved in product evaluation.

Related standards

• Complementary CEN standards on adhesives and timber product manufacturing (product-specific bonding standards and structural timber codes) should be consulted to ensure the bonding process and finished element meet overall structural requirements.

Keywords: EN 16254, EPI adhesives, emulsion polymerized isocyanate, load-bearing timber, adhesive classification, performance requirements, CEN, timber structures, industrial manufacture.