SIST EN 1313-1:2010

Overview

SIST EN 1313-1:2010 is a European Standard developed by CEN that defines permitted deviations and preferred sizes for softwood sawn timber. It focuses on the dimensional tolerances at a reference moisture content of 20% and provides guidance on adjustments required due to moisture-induced size changes. This standard is essential for manufacturers, suppliers, and users in the timber industry to ensure consistent quality and dimensional accuracy of softwood sawn timber products.

The document replaces the earlier EN 1313-1:1997 and introduces updated tables for metric-based target sizes along with complementary national sizing preferences across various European countries. The standard covers thicknesses of 38 mm and above and includes specific provisions related to green timber moisture conditions, especially relevant in France.

Key Topics

• Permitted Deviations

  • Thickness and width deviations at 20% moisture content:
    • For cross-sections ≤ 100 mm: +3 mm / -1 mm tolerance
    • For cross-sections > 100 mm: +4 mm / -2 mm tolerance
  • Length has no minus tolerance; plus tolerance is contract-dependent.

• Moisture Content Reference and Adjustments

  • Reference moisture content is set at 20%.
  • Dimensional changes occur with moisture variation at approximately ±0.25% size change per 1% moisture content deviation from 20%, applicable up to the fibre saturation point.
  • Adjustments accommodate size expansion in wetter conditions and shrinkage when drier.

• Preferred Timber Sizes

  • Common traditional target cross-sectional sizes are listed in both imperial and metric measures.
  • Preferred sizes for thicknesses 38 mm and above are specified for thickness and width to standardize production and market offerings.
  • Complementary national preferred sizes are included in an informative annex, reflecting country-specific market preferences and traditional dimensions.

• Complementary National Sizes and Green Timber

  • Annex A provides detailed preferred sizes for countries such as Austria, Germany, France, the UK, Sweden, Poland, Norway, and others.
  • France uniquely integrates the concept of preferred sizes for green timber, acknowledging timber dimensions at fibre saturation point (~28% moisture).

Applications

SIST EN 1313-1:2010 is applicable for:

• Sawmillers and timber processors to maintain dimensional standards and tolerances during production and processing of softwood sawn timber.
• Quality control and inspection agencies to verify compliance with European dimension tolerances and moisture-related size variations.
• Architects, engineers, and construction professionals rely on standardized timber sizes to ensure interoperability, accurate design specifications, and structural integrity of wooden elements.
• Timber traders and distributors to guarantee consistency in product offerings aligned with European market norms.
• Furniture manufacturers and carpenters who require uniform timber sizes for efficient production and fitting.

By adhering to this standard, stakeholders ensure that timber products meet industry requirements, reduce waste caused by dimensional discrepancies, and enhance cross-border trade with harmonized specifications.

Related Standards

SIST EN 1313-1:2010 is part of a series on sawn timber and relies on the following related standards for terminology and measurement methods:

• EN 844-series (1995–1997) on timber terminology, including terms on dimensions and moisture content.
• EN 1309-1 for methods of measurement of timber dimensions.

These standards complement EN 1313-1 by providing common vocabularies and precise measurement protocols essential for consistent implementation and communication across the timber supply chain.

Keywords: SIST EN 1313-1:2010, softwood sawn timber, timber size deviations, timber moisture content, timber size tolerances, preferred timber sizes, European timber standards, CEN timber standards, timber manufacturing, timber quality control.