Adhesives - One component polyurethane (PUR) for load-bearing timber structures - Classification and performance requirements

This document establishes a classification for one component polyurethane (PUR) adhesives according to their suitability for use in load-bearing timber products in defined climatic exposure conditions, and specifies performance requirements for such adhesives for the factory manufacture or factory-like manufacturing of load-bearing timber products only.
It also classifies “adhesive product lines” where all the products within the line have the same chemical composition except for a different amount of catalyst.
This document only specifies the performance of adhesives for use in an environment corresponding to the defined conditions.
The performance requirements of this document are applicable to the adhesives only, not to the manufactured timber products. This document does not cover the performance of adhesives for on-site gluing (except for factory-like conditions) or the production of wood-based panels, except solid wood panels, or modified and stabilized wood with considerably reduced swelling and shrinkage properties, e.g. acetylated wood, heat treated wood and polymer impregnated wood.
This document is primarily intended for use by adhesive manufacturers and for use in timber products bonded with adhesives, to assess or control the quality of adhesives. The requirements are applicable to the type testing of the adhesives. Production control activities are outside the scope of this document.
Adhesives meeting the requirements of this document are adequate for use in load-bearing timber products, provided that the bonding process has been carried out according to an appropriate product standard.
This document does not address the classification and use of adhesives in combination with the spraying of water before or during the bonding process; see informative Annex C of this document.
This does neither allow nor forbid the use of adhesives in combination with the spraying of water.

Klebstoffe - Einkomponenten-Klebstoffe auf Polyurethanbasis (PUR) für tragende Holzbauteile - Klassifizierung und Leistungsanforderungen

Adhésifs - Adhésifs polyuréthane monocomposants (PUR) pour structures portantes en bois - Classification et exigences de performance

Lepila - Enokomponentni poliuretan (PUR) za nosilne lesene konstrukcije - Razvrstitev in zahtevane lastnosti - Dopolnilo A1

General Information

Status
Not Published
Publication Date
05-Oct-2027
Technical Committee
CEN/TC 193 - Adhesives
Current Stage
4060 - Closure of enquiry - Enquiry
Start Date
25-Dec-2025
Due Date
12-Aug-2026
Completion Date
25-Dec-2025

Relations

Effective Date
02-Jul-2025

Overview

EN 15425:2023/prA1 is a European standard developed by CEN that specifies classification and performance requirements for one component polyurethane (PUR) adhesives used in load-bearing timber structures. This amendment outlines important modifications to the 2023 standard with a focus on adhesives' suitability under defined climatic exposure conditions in factory or factory-like environments.

The standard targets adhesive manufacturers as well as producers of timber products bonded with PUR adhesives, aiming to provide a robust framework for quality assessment and type testing of these adhesives. This helps ensure that adhesives meet performance criteria essential for structural timber applications.

Key Topics

  • Adhesive Classification
    The standard classifies one component PUR adhesives according to their chemical composition and catalyst content for use in load-bearing timber products. Adhesive product lines consist of products identical in chemistry except for catalyst variation.

  • Performance Requirements
    It establishes strict performance benchmarks for adhesives used in factory settings - focusing on durability, mechanical strength, and creep deformation limits under static load conditions. The amendment revises creep deformation criteria depending on glue line thickness and application area:

    • General purpose / finger-jointing: max 0.05 mm deformation
    • Special purpose (0.5 mm glue line): max 0.25 mm deformation
  • Scope Limitations
    The standard excludes adhesives for:

    • On-site glueing outside factory-like conditions
    • Wood-based panels other than solid wood panels
    • Modified woods like acetylated, heat-treated, or polymer-impregnated woods with altered swelling/shrinkage properties
    • Combination use with water spraying pre/during bonding (informative notes in Annex C)
  • Testing Focus
    EN 15425:2023/prA1 is primarily for type testing of adhesives and does not cover production control or the glued timber products’ performance itself.

Applications

  • Structural Timber Manufacturing
    Ensures bonded timber elements, such as beams and laminated boards, meet safety and performance standards necessary for load-bearing applications in construction.

  • Adhesive Quality Control
    Enables adhesive producers to demonstrate compliance to standardized performance requirements relevant for factory based timber bonding processes.

  • Product Development
    Facilitates formulation and classification of PUR adhesive product lines tailored to specific timber bonding needs, including varying catalyst levels to meet different application criteria.

Related Standards

  • EN 15425:2023 – Base version of the standard detailing initial specifications for one component PUR adhesives for timber
  • Product standards for load-bearing timber elements (e.g., EN 14080 for glulam beams) – require adhesives compliant with EN 15425 for bonding
  • European standards covering timber modification treatments (acetylation, heat treatment) which are excluded in this scope
  • Other adhesive standards under CEN/TC 193 overseeing different adhesive types and applications

Keywords: EN 15425:2023/prA1, one component polyurethane adhesive, PUR adhesive, load-bearing timber structures, timber adhesive classification, adhesive performance, factory timber bonding, polyurethane adhesive standard, static load test, timber construction adhesives, European standard adhesives, adhesive quality assessment.

Draft

EN 15425:2023/oprA1:2025

English language
4 pages
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Frequently Asked Questions

EN 15425:2023/prA1 is a draft published by the European Committee for Standardization (CEN). Its full title is "Adhesives - One component polyurethane (PUR) for load-bearing timber structures - Classification and performance requirements". This standard covers: This document establishes a classification for one component polyurethane (PUR) adhesives according to their suitability for use in load-bearing timber products in defined climatic exposure conditions, and specifies performance requirements for such adhesives for the factory manufacture or factory-like manufacturing of load-bearing timber products only. It also classifies “adhesive product lines” where all the products within the line have the same chemical composition except for a different amount of catalyst. This document only specifies the performance of adhesives for use in an environment corresponding to the defined conditions. The performance requirements of this document are applicable to the adhesives only, not to the manufactured timber products. This document does not cover the performance of adhesives for on-site gluing (except for factory-like conditions) or the production of wood-based panels, except solid wood panels, or modified and stabilized wood with considerably reduced swelling and shrinkage properties, e.g. acetylated wood, heat treated wood and polymer impregnated wood. This document is primarily intended for use by adhesive manufacturers and for use in timber products bonded with adhesives, to assess or control the quality of adhesives. The requirements are applicable to the type testing of the adhesives. Production control activities are outside the scope of this document. Adhesives meeting the requirements of this document are adequate for use in load-bearing timber products, provided that the bonding process has been carried out according to an appropriate product standard. This document does not address the classification and use of adhesives in combination with the spraying of water before or during the bonding process; see informative Annex C of this document. This does neither allow nor forbid the use of adhesives in combination with the spraying of water.

This document establishes a classification for one component polyurethane (PUR) adhesives according to their suitability for use in load-bearing timber products in defined climatic exposure conditions, and specifies performance requirements for such adhesives for the factory manufacture or factory-like manufacturing of load-bearing timber products only. It also classifies “adhesive product lines” where all the products within the line have the same chemical composition except for a different amount of catalyst. This document only specifies the performance of adhesives for use in an environment corresponding to the defined conditions. The performance requirements of this document are applicable to the adhesives only, not to the manufactured timber products. This document does not cover the performance of adhesives for on-site gluing (except for factory-like conditions) or the production of wood-based panels, except solid wood panels, or modified and stabilized wood with considerably reduced swelling and shrinkage properties, e.g. acetylated wood, heat treated wood and polymer impregnated wood. This document is primarily intended for use by adhesive manufacturers and for use in timber products bonded with adhesives, to assess or control the quality of adhesives. The requirements are applicable to the type testing of the adhesives. Production control activities are outside the scope of this document. Adhesives meeting the requirements of this document are adequate for use in load-bearing timber products, provided that the bonding process has been carried out according to an appropriate product standard. This document does not address the classification and use of adhesives in combination with the spraying of water before or during the bonding process; see informative Annex C of this document. This does neither allow nor forbid the use of adhesives in combination with the spraying of water.

EN 15425:2023/prA1 is classified under the following ICS (International Classification for Standards) categories: 83.180 - Adhesives. The ICS classification helps identify the subject area and facilitates finding related standards.

EN 15425:2023/prA1 has the following relationships with other standards: It is inter standard links to EN 15425:2023. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.

EN 15425:2023/prA1 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.

Standards Content (Sample)


SLOVENSKI STANDARD
01-december-2025
Lepila - Enokomponentni poliuretan (PUR) za nosilne lesene konstrukcije -
Razvrstitev in zahtevane lastnosti - Dopolnilo A1
Adhesives - One component polyurethane (PUR) for load-bearing timber structures -
Classification and performance requirements
Klebstoffe - Einkomponenten-Klebstoffe auf Polyurethanbasis (PUR) für tragende
Holzbauteile - Klassifizierung und Leistungsanforderungen
Adhésifs - Adhésifs polyuréthane monocomposants (PUR) pour structures portantes en
bois - Classification et exigences de performance
Ta slovenski standard je istoveten z: EN 15425:2023/prA1
ICS:
83.180 Lepila Adhesives
91.080.20 Lesene konstrukcije Timber structures
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
EN 15425:2023
NORME EUROPÉENNE
EUROPÄISCHE NORM
prA1
October 2025
ICS 83.180
English Version
Adhesives - One component polyurethane (PUR) for load-
bearing timber structures - Classification and performance
requirements
Adhésifs - Adhésifs polyuréthane monocomposants Klebstoffe - Einkomponenten-Klebstoffe auf
(PUR) pour structures portantes en bois - Classification Polyurethanbasis (PUR) für tragende Holzbauteile -
et exigences de performance Klassifizierung und Leistungsanforderungen
This draft amendment is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 193.

This draft amendment A1, if approved, will modify the European Standard EN 15425:2023. 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,
...

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