Overview
ISO 16696-1:2019 - "Timber structures - Cross laminated timber - Part 1: Component performance, production requirements and certification scheme" - sets the baseline requirements for the manufacture, performance assessment and conformity of cross laminated timber (CLT) products. It applies to CLT built from solid‑sawn timber or wood‑based panels composed of at least three layers with adjacent layer grain at right angles. The standard covers dimensional tolerances, component and adhesive requirements, performance criteria, production control, testing and trade‑marking guidance. Annex D defines the conformance/certification scheme.
Key technical topics and requirements
- Scope of applicability: CLT from known species or combinations and wood‑based panels; intended to resist moisture effects encountered in construction conditions.
- Dimensional tolerances: Requirements for panel thickness, layer thickness, width, length, squareness and straightness at manufacture and corrected sizes related to moisture content.
- Component requirements:
- Solid sawn timber and wood‑based panel specifications (sizes, face‑bonding surfaces, moisture content).
- Ply grading and allowable species/combination considerations.
- Adhesive and bond performance:
- Requirements for adhesives (bond integrity), testing for adhesive changes, finger and edge joint performance and glue‑line integrity.
- Mechanical and durability performance:
- Layup rules, mechanical resistance (strength and stiffness) expectations, durability against biological attack, and formaldehyde emission evaluation referenced to relevant test methods.
- Production and quality control:
- Minimum factory production control (FPC) criteria, sampling and testing procedures, trade marking and production assessment processes (Annex D).
- Normative and informative annexes:
- Layup examples (Annex A), appearance classification (Annex B), ply grading (Annex C), certification scheme and FPC details (Annex D), supplementary properties (Annex E).
Practical applications and who uses it
ISO 16696-1 is used by:
- CLT manufacturers - to design production lines, specify adhesives, and document factory production control and trade marking.
- Structural engineers and designers - to verify component performance, dimensional tolerances and layup requirements for load calculations.
- Architects and specifiers - to select compliant CLT products and confirm durability/appearance classes.
- Testing laboratories and certification bodies - to assess bond performance, mechanical properties and formaldehyde emissions and to implement the conformance scheme in Annex D.
- Building regulators and procurement teams - to reference minimum performance and production requirements for approval and contract specification.
Related standards
- ISO 16696-2 (CLT installation and use guidance)
- EN 16351, ANSI/APA PRG 320 (source standards informing ISO 16696 series)
- Relevant test standards cited: ISO/IEC 12460 (formaldehyde), ISO 20152 (bond performance), ISO/IEC 13910, ISO/IEC 16979 and ISO/IEC 3130 (moisture and sampling)
Keywords: ISO 16696-1, cross laminated timber, CLT, production requirements, component performance, certification scheme, dimensional tolerances, factory production control, adhesive requirements.