Overview
ISO 13059:2011 - Round timber: measurement of dimensions and determination of volume establishes uniform requirements for measuring round timber (logs) and for calculating their volume. Developed by ISO/TC 218 (Timber) and based on EN 1309-2:2006, the standard harmonizes measurement practices to reduce technical barriers in international timber trade and to ensure consistent, reproducible volume reporting.
Key principles in the standard include the use of metric units, certified measurement procedures and measurement instruments, and methods that minimise personal influence on results.
Key Topics
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Measurement units and accuracy: Metric units are required. Instruments for diameter measurement must provide ±1 mm accuracy and length measurement ±1 cm.
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Dimensions defined: The standard defines diameter, length, nominal length and crosscut allowance, and clarifies measurement positions (butt, top, mid) and special cases (buttress, multiple sweep, undercut/butt trimming).
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Rounding rules: Diameter measurements are rounded to whole centimetres (0.5 cm and above rounded up); length is measured to the shortest distance between ends and rounded to 0.01 m.
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Measurement methods: Supports direct and indirect measurement methods, including piece-by-piece measurements and group methods (pile, mass, hydrostatic/xylometric, photographic, electron-optical). Conversion rules must be defined when measuring over or under bark.
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Volume calculation: Volume is calculated by multiplying cross-sectional area by nominal length. The standard covers piece-by-piece solid volume, piled volume (using a coefficient of timber compactness to convert piled to solid volume), and group determination methods.
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Procedural requirements: Measurement procedures must be certified, define the place and number of direct measurements for pile methods, and provide rules for rounding results (e.g., individual log volumes rounded to 0.001 m³, lot volumes to 0.01 m³ or 0.001 m³ depending on method).
Applications
ISO 13059:2011 is practical for:
- Timber producers and sawmills establishing consistent measurement workflows and documentation.
- Forest managers and loggers performing on-site piece-by-piece volume determinations.
- Transporters and traders calculating carload, ship or vehicle volumes (including mass-based methods and gross/net weight approaches).
- Quality control, forestry certification and valuation professionals needing standardized, auditable volume figures for contracts and international trade.
Benefits include improved accuracy, reduced measurement disputes, simplified trade operations, and harmonized reporting across jurisdictions.
Related Standards
- ISO 4476:1983 - Vocabulary for log sizes
- ISO/IEC Guide 99:2007 - Metrology vocabulary (VIM)
- EN 1309-2:2006 - Source for development
Other referenced national standards and norms (e.g., GOST, GB/T, STB) can provide complementary tables, compactness coefficients and local measurement practices. When in doubt, the piece-by-piece method is prescribed if group-method results conflict.