ISO 19474:2018

Overview

ISO 19474:2018 - Round timber - Visual characteristics - Methods of determination (ISO, First edition 2018-03) specifies uniform methods for identifying and measuring the visual characteristics of round timber. The standard defines how to record and quantify visible features that affect log quality, grading and commercial valuation. It promotes consistent timber inspection procedures across forestry, sawmill and trading operations to reduce technical barriers in international timber trade.

Key topics and requirements

ISO 19474:2018 sets out measurement methods and notations for a comprehensive set of visual characteristics. Important technical topics include:

• Knots

  • Measurement of uncovered knot diameter (expressed in millimetres).
  • Notation of covered knots when measurements are not required.
  • Special features such as roses, epicormic shoots and “Chinese moustache” (measured or noted depending on grade).

• Shakes and cracks

  • Heart shake, star shake and ring shake: methods to measure depth, diameter or note presence.
  • Frost cracks, lightning/shake, drying cracks and through shakes: depth (mm), length (cm) or percentage relative to timber diameter or length.

• Trunk shape characteristics

  • Sweep (simple and multiple): measurement of sagitta (maximum deviation) either per metre or as a percentage of log length or mid‑diameter.
  • Ovality and tapering are listed as measurable shape parameters.

• Wood structure and biological factors

  • Spiral grain, reaction wood, annual ring width, double pith, false heartwood, sapwood/heart sapwood and scars.
  • Biological defects: fungal decay, insect holes, parasitic plant damage and bird damage-documented and measured or noted.

• Mechanical and other characteristics

  • Tapping cuts, stripped bark, incisions, saw‑cuts and harvesting damages are covered for notation or measurement.

• Units and notation

  • Measurements use millimetres, centimetres or percentages (relative to diameter or length) as appropriate.

Practical applications and users

ISO 19474:2018 is intended for professionals needing standardized visual assessment of round timber, including:

• Forestry and logging companies for on‑stump quality assessment
• Sawmills and log buyers for incoming inspection and grading
• Timber traders and exporters/importers for contract specifications and dispute resolution
• Quality control, certification bodies and technical committees harmonizing timber grading
• Researchers and consultants documenting timber defects and tree morphology

Using these standardized methods improves consistency in timber grading, pricing, sorting, and reporting across national and international markets.

Related standards

• ISO 24294 (Timber - Round and sawn timber - Vocabulary) - normative reference for terms and definitions.
• The document harmonizes with existing systems such as EN 1310 and EN 1311, and national standards referenced in the introduction.

Keywords: ISO 19474:2018, round timber, visual characteristics, methods of determination, timber grading, log inspection, timber standards, timber quality.