SIST EN 384:2016+A1:2019/kprA2:2022

Structural timber - Determination of characteristic values of mechanical properties and density

This European Standard gives a method for determining characteristic values of mechanical properties and density, for defined populations of visual grades and/or strength classes of machine graded structural timber. Additionally it covers the stages of sampling, testing, analysis and presentation of the data.
The standard provides methods to derive strength, stiffness and density properties for structural timber from tests with defect-free specimen.
The values determined in accordance with this standard for mechanical properties and density are suitable for assigning grades and species to the strength classes of EN 338.
NOTE 1   For assigning grades and species to the strength classes in EN 338 only three properties, i.e. bending or tension strength, modulus of elasticity parallel to grain in bending or tension and density need to be determined from test data, other properties can be calculated according to Table 2.
NOTE 2   EN 1912 gives examples of established visual grades assigned to strength classes.

Bauholz für tragende Zwecke - Bestimmung charakteristischer Werte für mechanische Eigenschaften und Rohdichte

Bois de structure - Détermination des valeurs caractéristiques des propriétés mécaniques et de la masse volumique

Konstrukcijski les - Ugotavljanje karakterističnih vrednosti mehanskih lastnosti in gostote

General Information

• Status: Not Published
• Public Enquiry End Date: 09-Jan-2020
• ICS: 79.040 - Wood, sawlogs and sawn timber
• ICS: 91.080.20 - Timber structures
• Technical Committee: KON.005 - Timber structures
• Current Stage: 98 - Abandoned project (Adopted Project)
• Start Date: 01-Aug-2022
• Due Date: 06-Aug-2022
• Completion Date: 01-Aug-2022
• Ref Project: EN 384:2016+A1:2018/FprA2 - Structural timber - Determination of characteristic values of mechanical properties and density

Relations

• Consolidated By: SIST EN 384:2016+A2:2022 - Structural timber - Determination of characteristic values of mechanical properties and density
• Effective Date: 01-Sep-2022
• Amends: SIST EN 384:2016+A1:2019 - Structural timber - Determination of characteristic values of mechanical properties and density
• Effective Date: 01-Jan-2020

Overview

EN 384:2016+A1:2018/FprA2 is a CEN European Standard that specifies a method to determine characteristic values of mechanical properties and density for structural timber. It covers sampling, testing, statistical analysis and presentation of results for defined populations of visual grades and/or machine-graded timber. The standard produces values suitable for assigning grades and species to the strength classes of EN 338.

Key topics and technical requirements

• Scope: Derivation of strength, stiffness and density properties from tests on defect‑free specimens for structural timber populations (visual or machine graded).
• Sampling: Samples must be representative of the population, explicitly including commercial practices. Requirements address specimen lengths for bending and tension tests and caution against bias by selecting atypically long pieces.
• Moisture content: Test results must be adjusted to reference conditions (normally 12% moisture content) using documented methods. The standard provides adjustment guidance for moisture contents in the typical range (8–18%) and notes special consideration when u < 8% or above fibre saturation.
• Adjustment formulas (simplified methods provided by the standard):
  • Density: ρ = ρ(u)·(1 − 0.005·(u − u_ref))
  • Modulus of elasticity parallel to grain: E = E(u)·(1 + 0.01·(u − u_ref))
  • Compression parallel to grain: f_c = f_c(u)·(1 + 0.03·(u − u_ref))
  • Where u_ref is normally 12% and u is test moisture content (8% ≤ u ≤ 18% unless otherwise justified).
• Required properties for EN 338 assignment: Only three properties typically need to be determined from test data to assign to EN 338 strength classes - bending or tension strength, modulus of elasticity parallel to grain (in bending or tension) and density. Other properties may be calculated per the standard.
• Reporting: Test methods, adjustments used, and any deviations (e.g., shorter specimen lengths) must be justified and recorded in the test report.

Applications and users

Who uses EN 384:

• Testing laboratories and certification bodies performing structural timber characterization and grading.
• Timber manufacturers and sawmills for machine‑grading calibration and product specification.
• Structural engineers and specifiers who require validated characteristic properties for design and verification.
• Standards bodies and researchers developing or comparing strength classes.

Practical uses:

• Assigning timber to EN 338 strength classes.
• Quality control, CE marking support, and compliance checks.
• Producing design values for structural calculations and reliability assessments.

Related standards

• EN 338 - Strength classes of structural timber
• EN 408 - Structural timber - sizes and test methods (referenced for specimen length and testing)
• EN 1912 - Examples of visual grades assigned to strength classes

Keywords: EN 384, structural timber, mechanical properties, density, characteristic values, timber grading, EN 338, moisture content, modulus of elasticity, sampling.

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 384:2016+A1:2019/oprA2:2020
01-januar-2020
Konstrukcijski les - Ugotavljanje karakterističnih vrednosti mehanskih lastnosti in
gostote
Structural timber - Determination of characteristic values of mechanical properties and
density
Bauholz für tragende Zwecke - Bestimmung charakteristischer Werte für mechanische
Eigenschaften und Rohdichte
Bois de structure - Détermination des valeurs caractéristiques des propriétés
mécaniques et de la masse volumique
Ta slovenski standard je istoveten z: EN 384:2016+A1:2018/prA2
ICS:
79.040 Les, hlodovina in žagan les Wood, sawlogs and sawn
timber
91.080.20 Lesene konstrukcije Timber structures
SIST EN 384:2016+A1:2019/oprA2:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

SIST EN 384:2016+A1:2019/oprA2:2020

SIST EN 384:2016+A1:2019/oprA2:2020

DRAFT
EUROPEAN STANDARD
EN 384:2016+A1:2018
NORME EUROPÉENNE
EUROPÄISCHE NORM
prA2
November 2019
ICS 79.040
English Version
Structural timber - Determination of characteristic values
of mechanical properties and density
Bois de structure - Détermination des valeurs Bauholz für tragende Zwecke - Bestimmung
caractéristiques des propriétés mécaniques et de la charakteristischer Werte für mechanische
masse volumique Eigenschaften und Rohdichte
This draft amendment is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 124.

This draft amendment A2, if approved, will modify the European Standard EN 384:2016+A1:2018. If this draft becomes an
amendment, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for
inclusion of this amendment into the relevant national standard without any alteration.

This draft amendment was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 384:2016+A1:2018/prA2:2019 E
worldwide for CEN national Members.

SIST EN 384:2016+A1:2019/oprA2:2020
EN 384:2016+A1:2018/prA2:2019 (E)
Contents Page
European foreword . 3
1 Modifications to 5.1, "Sampling" . 4
2 Modification to 5.4.2, "Moisture content" . 4
...