ISO 4561:2023

Overview

ISO 4561:2023 - Wood raw parquets elements - Classification - defines the international classification, by quality, of raw parquet elements used to manufacture strips for parquet flooring. It covers six wood species: oak (Quercus sp.), beech (Fagus sylvatica sp.), birch (Betula sp.), maple (Acer sp.), fir (Abies sp.) and spruce (Picea sp.). This first edition merges and updates earlier ISO documents and is prepared by ISO/TC 218 (Timber).

Key SEO phrases: ISO 4561, wood raw parquet elements, parquet classification, parquet quality grades, oak beech birch maple fir spruce.

Key topics and technical requirements

ISO 4561 specifies classification rules, permissible defects and delivery/manufacture references. Main technical topics include:

• Grades: raw parquet elements are divided into Grade I, Grade II and Grade M (M applies only to oak). Elements exceeding allowed defects must not be sold under ISO designations for the species.
• Manufacture and delivery: manufacturing characteristics and delivery conditions are defined by ISO 4556; beech elements are steamed prior to delivery unless otherwise requested.
• General dimensional/appearance limits:
  • Slope of grain not exceeding 10% relative to piece axis.
  • Bow allowed on one plane up to 1% of piece length.
  • Spring (crook) allowed up to 0.5% of piece length.
  • Cup (fir/spruce only) allowed up to 2 mm across width.
  • Saw marks permitted up to 0.5 mm depth.
• Defect limits (select examples from tables for face, back, ends and edges):
  • Shallow checks: typically 1 mm (Grade I) up to 2–4 mm (Grade II depending on species and face/back).
  • Sound knots: permitted sizes vary by species and grade (e.g., up to 10–20 mm on oak faces; 15–25 mm on other species for some grades).
  • Black/dead knots: stricter limits (often 1–10 mm on faces, larger allowances on backs/edges).
  • Wane, curl, bore-holes and pitch-pockets: specific allowances differ by species and grade; number of face defects limited (e.g., max 3 defects for Grade I, 4 for Grade II in some cases).

The standard relies on vocabulary and terms from ISO 5323 and ISO 24294.

Applications and who uses it

ISO 4561 is used by:

• Parquet manufacturers and millworkers specifying raw parquet grade for production of strips and finished parquet flooring.
• Timber merchants and buyers for product acceptance, inspection and contracting.
• Quality control and inspection personnel establishing compliance with permitted defect limits.
• Architects, specifiers and procurement teams writing technical product requirements for projects.
• Standards bodies and testing laboratories harmonizing classification and trade descriptions.

Practical benefits include consistent grading, improved trade clarity, and reduced disputes over raw parquet element quality.

Related standards

• ISO 4556 - Wood raw parquet elements - General characteristics (manufacture/delivery).
• ISO 5323 - Wood flooring and parquet - Vocabulary.
• ISO 24294 - Timber - Round and sawn timber - Vocabulary.

For full numeric tables, defect definitions and complete requirements consult the official ISO 4561:2023 document.