Overview
ISO 13910:2014 - Timber structures - Strength graded timber - Test methods for structural properties - defines standardized test procedures for full‑size, strength‑graded sawn timber used to derive engineering (design) properties for structural codes. It applies to rectangular cross‑section timber subjected to short‑duration loads and establishes specimen selection, conditioning, test configurations, measurement methods and reporting requirements used to determine density, bending, tension, compression, shear and torsional properties.
Key technical topics and requirements
- Scope and specimens
- Tests apply to full‑size sawn timber pieces of rectangular cross‑section; specimens are normally cut from random locations within a piece.
- Each specimen for a given size/grade/property must come from a different piece of timber.
- Reference test conditions
- Reference conditioning is 20 °C (±2 °C) and 65 % (±5 %) RH unless otherwise specified.
- Target average time‑to‑failure for short‑duration tests is 1 to 5 minutes; timber moisture content, temperature and time to failure must be recorded.
- Measured properties and configurations
- Density: oven‑dry and adjusted values at 12 % moisture content; specimen free of knots and at least 50 mm long.
- Bending strength and stiffness: two‑point loading beam test (specified load/span relationships relative to section depth h); modulus of elasticity (E) and bending strength (f_m) calculated from measured loads and deflections.
- Tension and compression parallel to grain: full‑length compression tests with lateral restraints or short‑specimen alternatives where equivalence is established; tension tests with specified gauge lengths and gripping.
- Shear, compression/tension perpendicular to grain, torsional shear modulus: defined test setups and calculation methods for each property (see Clause 6).
- Adjustments and reporting
- Clause 7 and Annex A cover adjustments for non‑reference test conditions and equivalency. A comprehensive test report format is required (Clause 8).
Practical applications and users
- Structural engineers and design code authors use ISO 13910:2014 to derive reliable design values (bending strength, E, shear, etc.) for strength‑graded timber.
- Timber manufacturers and grading houses apply these test methods for product qualification and strength grading verification.
- Testing laboratories and certification bodies adopt the standard to ensure consistent, repeatable measurement and to support regulatory compliance and quality control.
- Researchers in wood mechanics use the defined configurations and measurement protocols for comparative studies.
Related standards and value
- ISO 13910:2014 is maintained by ISO/TC 165 (Timber Structures) and supersedes the 2005 edition. Other measurement standards may be declared equivalent if appropriate adjustment factors and equivalency procedures are applied (see Annex A). Using ISO 13910 promotes consistent timber testing, traceable design data and alignment with international structural timber practice.
Keywords: ISO 13910:2014, strength graded timber, timber testing, structural properties, bending strength, modulus of elasticity, compression strength, shear strength, torsional shear modulus, density, moisture content.
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