FprEN 13408

• Abstract:

  This document specifies a test method for the determination of bond strength between an underlayment produced with cementitious or calciumsulfate-based floor levelling compounds and a standard substrate.; This document applies to cementitious, and calcium sulphate-based floor levelling compounds used for the preparation of subfloors to ensure the suitability of the substrate prior to the installation of floor coverings. By using the floor levelling compound, a homogeneous layer is built up on the load-bearing substrate, to ensure consistent absorbency, evenness and strength.

• Status: Not Published
• Publication Date: 17-Feb-2027
• ICS: 91.100.99 - Other construction materials
• Technical Committee: CEN/TC 193 - Adhesives
• Drafting Committee: CEN/TC 193/WG 4 - Building adhesives
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 26-Aug-2026
• Due Date: 16-Feb-2026
• Completion Date: 26-Aug-2026
• Ref Project: oSIST prEN 13408:2026 - Adhesives - Test method for cementitious and calciumsulfate-based floor levelling compounds - Determination of bond strength

• Revises: EN 13408:2002 - Methods of test for hydraulic setting floor smoothing and/or levelling compounds - Determination of bond strength
• Effective Date: 08-May-2024

FprEN 13408 is a CEN draft European Standard for determining the bond strength of cementitious and calciumsulfate-based floor levelling compounds against a standard substrate. It gives a laboratory test method for measuring how strongly a set levelling layer adheres to concrete under controlled conditions. The document is meant for people who test, specify, or assess floor levelling compounds before floor coverings are installed.

What does FprEN 13408 specify?

FprEN 13408 specifies a test method for bond strength between an underlayment made with cementitious or calcium sulphate-based floor levelling compounds and a standard substrate. In practice, it is used to check whether the levelling compound forms a sound bonded layer on the load-bearing substrate before floor covering work starts.

FprEN 13408 is organized into clauses on scope, normative references, terms and definitions, principle, standard test conditions, apparatus and material, procedure, evaluation and expression of results, and test report. Clause 4 explains the pull-off principle, Clauses 5 to 7 cover the test setup and steps, Clause 8 explains how to calculate and average results, and Clause 9 lists the report contents.

What are the key requirements of FprEN 13408?

FprEN 13408 requires a pull-off type bond test on a set floor levelling compound applied to a standard concrete test slab. Metal plates are bonded to the cured surface and pulled off perpendicularly and centrally. That means the method measures the interface strength in a controlled way rather than judging the material by appearance alone.

• Clause 5 - standard test conditions: The test is carried out at controlled temperature and humidity, with low air movement, and materials and apparatus are kept under those conditions. This reduces variation from curing or moisture effects.
• Clause 6 - apparatus and material: The method uses a tensile testing machine, a concrete slab, flexible moulding sheets, a fast-setting reactive resin adhesive, rigid metal plates, the prepared compound mixture, and primer if the manufacturer specifies it. This ensures the specimen is built the same way each time.
• Clause 7.2 - specimen preparation: Eight test areas are required for each floor levelling compound. The compound is placed into mould cavities, excess is removed to give an even surface, and the moulding sheet is removed within three days without damaging the areas.
• Clause 7.2 - loading and timing: Metal plates are bonded to the test areas within the 24 hours before testing, the adhesive must be fully cured, and the test is performed 14 days after mixing. The plate is then pulled at a controlled force increase rate, so the result is comparable between tests.
• Clause 7.2 - failure reporting: The breaking load and failure mode are recorded using the EN ISO 10365 failure pattern names. This helps the reader see whether the weak point was the compound, the substrate, or the adhesive bond to the plate.
• Clause 8 - result evaluation: Bond strength is calculated from the breaking load and bonded area, then the arithmetic mean of the eight results is reported. Outliers are handled by discarding the value that differs most when a result is more than 20 % from the mean; if too few results remain, the test is repeated.
• Clause 9 - test report: The report must identify the product, primer details if used, mixing proportions and time, thickness, bond strength, failure mode, deviations, and test date. This is the traceability record for quality control or technical claims.

What terms does FprEN 13408 define?

• Bond strength - the force per unit area applied perpendicularly and centrally to the bonded area to cause failure.
• Underlayment - the layer produced by the floor levelling compound on the substrate for the test.
• Standard substrate - the concrete test slab used as the reference support in this method.
• Primer - a surface treatment used when specified by the compound manufacturer before placing the levelling compound.
• Tensile testing machine - the machine used to pull the bonded metal plate off the specimen in a controlled way.
• Failure mode - the way the specimen breaks, reported as a named pattern under EN ISO 10365.

Who uses FprEN 13408?

FprEN 13408 is used by testing laboratories, manufacturers of cementitious and calcium sulphate-based floor levelling compounds, and quality assurance teams that need a repeatable bond-strength result. It is also relevant to technical specifiers and buyers who need to compare products or confirm that a levelling compound is suitable for preparing subfloors before floor coverings are installed.

What changed in FprEN 13408 from the previous edition?

FprEN 13408:2026 will supersede EN 13408:2002. The draft states these main changes:

• the term “hydraulic setting floor smoothing and/or levelling compounds” has been replaced with “cementitious and calciumsulfate-based floor levelling compounds”;
• the scope has been made more specific;
• the normative references have been updated;
• editorial changes have been made.

Which standards are used with FprEN 13408?

• EN 923 - provides terms and definitions used alongside the terms in FprEN 13408.
• EN 12004-2 - specifies the concrete slab referenced for the test setup.
• prEN 1937:2026 - gives the standard mixing procedures for the prepared floor levelling compound mixture.
• EN ISO 10365 - provides the failure pattern names used when reporting how the test specimen broke.
• ISO 554 - sets the standard atmospheres used for conditioning and testing.

What does the FprEN 13408 document contain?

FprEN 13408 contains the full laboratory method needed to prepare specimens, condition the materials, and measure bond strength. Clause 6 defines the apparatus and materials, Clause 7 gives the preconditioning and test sequence, and Clause 8 explains how to calculate and present the results. Clause 9 gives the reporting items needed for test records, technical files, or product evaluation.

SLOVENSKI STANDARD
01-april-2026
Lepila - Preskusna metoda za cementne in kalcijsulfatne izravnalne mase za tla -
Ugotavljanje trdnosti vezave
Adhesives - Test method for cementitious and calciumsulfate-based floor levelling
compounds - Determination of bond strength
Klebstoffe - Prüfverfahren für zement- und calciumsulfatbasierte Bodenspachtelmassen -
Bestimmung der Haftzugfestigkeit
Adhésifs - Méthode d’essai pour les mortiers de nivellement à base de ciment et de
sulfate de calcium - Détermination de la force de liaison
Ta slovenski standard je istoveten z: prEN 13408
ICS:
91.100.99 Drugi gradbeni materiali Other construction materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
prEN 13408
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2026
ICS 91.100.99 Will supersede EN 13408:2002
English Version
Adhesives - Test method for cementitious and
calciumsulfate-based floor levelling compounds -
Determination of bond strength
Adhésifs - Méthode d'essai pour les mortiers de Klebstoffe - Prüfverfahren für zement- und
nivellement à base de ciment et de sulfate de calcium - calciumsulfatbasierte Bodenspachtelmassen -
Détermination de la force de liaison Bestimmung der Haftzugfestigkeit
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 193.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

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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.

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EUROPÄISCHES KOMITEE FÜR NORMUNG

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© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 13408:2026 E
worldwide for CEN national Members.

prEN 13408:2026 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Principle . 5
5 Standard test conditions . 5
6 Apparatus and material . 6
7 Procedure . 6
7.1 Preconditioning . 6
7.2 Test procedure . 6
8 Evaluation and expression of results . 7
9 Test report . 7
prEN 13408:2026 (E)
European foreword
This document (prEN 13408:2026) has been prepared by Technical Committee CEN/TC 193 “Adhesives”,
the secretariat of which is held by UNE.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 13408:2002.
prEN 13408:2026 includes the following significant technical changes with respect to EN 13408:2002:
— term “hydraulic setting floor smoothing and/or levelling compounds” changed to “cementitious and
calciumsulfate-based floor levelling compounds”;
— concretisation of the scope;
— updated normative references;
— editorial changes.
prEN 13408:2026 (E)
Introduction
Persons using this document are to be familiar with normal laboratory practice.
This document does not purport to address all the safety problems, if any, associated
...