SIST EN ISO 23999:2026

SLOVENSKI STANDARD
01-februar-2026
Netekstilne talne obloge - Ugotavljanje dimenzijske stabilnosti in gubanja
(navpična deformacija) po izpostavitvi toploti (ISO 23999:2025)
Resilient floor coverings - Determination of dimensional stability and curling (vertical
deformation) after exposure to heat (ISO 23999:2025)
Elastische Bodenbeläge - Bestimmung der Maßhaltigkeit und Schüsselung (vertikale
Verformung) nach Wärmeeinwirkung (ISO 23999:2025)
Revêtements de sol résilients - Détermination de la stabilité dimensionnelle et de
l'incurvation après exposition à la chaleur (ISO 23999:2025)
Ta slovenski standard je istoveten z: EN ISO 23999:2025
ICS:
97.150 Talne obloge Floor coverings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 23999
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2025
EUROPÄISCHE NORM
ICS 97.150 Supersedes EN ISO 23999:2021
English Version
Resilient floor coverings - Determination of dimensional
stability and curling (vertical deformation) after exposure
to heat (ISO 23999:2025)
Revêtements de sol résilients - Détermination de la Elastische Bodenbeläge - Bestimmung der
stabilité dimensionnelle et de l'incurvation Maßhaltigkeit und Schüsselung (vertikale Verformung)
(déformation verticale) après exposition à la chaleur nach Wärmeeinwirkung (ISO 23999:2025)
(ISO 23999:2025)
This European Standard was approved by CEN on 23 November 2025.

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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists 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, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 23999:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 23999:2025) has been prepared by Technical Committee ISO/TC 219 "Floor
coverings" in collaboration with Technical Committee CEN/TC 134 “Resilient, textile, laminate and
modular mechanical locked floor coverings” the secretariat of which is held by NBN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by June 2026, and conflicting national standards shall be
withdrawn at the latest by June 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 23999:2021.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: 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, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 23999:2025 has been approved by CEN as EN ISO 23999:2025 without any modification.

International
Standard
ISO 23999
Fourth edition
Resilient floor coverings —
2025-11
Determination of dimensional
stability and curling (vertical
deformation) after exposure to heat
Revêtements de sol résilients — Détermination de la stabilité
dimensionnelle et de l’incurvation (déformation verticale) après
exposition à la chaleur
Reference number
ISO 23999:2025(en) © ISO 2025
ISO 23999:2025(en)
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 23999:2025(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
4.1 General .2
4.2 Dimensional stability .2
4.3 Curling (vertical deformation) .2
5 Apparatus . 2
5.1 Oven.2
5.2 Support plates .3
6 Measuring devices . 3
6.1 Measurement devices for determination of curling (vertical deformation) .3
6.2 Measurement devices for determination of linear dimension changes .3
6.2.1 General .3
6.2.2 Scoring device .3
6.2.3 Rigid steel plate .3
6.2.4 Block and dial gauge apparatus (for tiles and planks) .4
7 Test specimens . 6
7.1 Specimen preparation from sheet or roll material .6
7.2 Specimen preparation from tiles and planks .8
8 Conditioning . 8
9 Test procedure . 8
9.1 Initial measurement .8
9.1.1 Curling (vertical deformation) .8
9.1.2 Linear dimensions . . .9
9.2 Heat exposure.10
9.3 Reconditioning.10
9.4 Final measurement .10
9.4.1 Curling (vertical deformation) .10
9.4.2 Linear dimensions . . .10
10 Calculation and expression of results .11
10.1 Curling (vertical deformation) .11
10.2 Dimensional change .11
11 Test report .12
Annex A (informative) Measurement of dimensional change due to heat .13
Annex B (informative) Calculation and expression of results . 14

iii
ISO 23999:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see http://www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
http://www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization
(WTO) principles in the Technical Barriers to Trade (TBT), see http://www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 219, Floor coverings, in collaboration with the
European Committee for Standardization (CEN) Technical Committee CEN/TC 134 Resilient, textile, laminate
and modular mechanical locked floor coverings, in accordance with the Agreement on technical cooperation
between ISO and CEN (Vienna Agreement).
This fourth edition cancels and replaces the third edition (ISO 23999:2021), which has been technically
revised.
The main changes are as follows:
— revision of terms and definitions;
— clarification on the deviation between devices used for either sheet or roll, or both, materials and
rectangular shaped elements (squared tiles or long panels);
— inclusion of an explanation on the use of the so called “block and dial gauge apparatus” and minor changes
to the figures and a new figure was added;
— inclusion of description of the preparation distinguishing sheet, roll materials and rectangular shaped
elements (squared tiles or long panels);
— detailed calculation and expression of results can be found in new Annex B.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at http://www.iso.org/members.html.

iv
International Standard ISO 23999:2025(en)
Resilient floor coverings — Determination of dimensional
stability and curling (vertical deformation) after
exposure to heat
1 Scope
This document specifies methods for determining dimensional stability and curling (vertical deformation)
of resilient floor coverings in all forms (e.g. of sheets, tiles, panels, planks or in rolls) after exposure to either
heat or after reconditioning, or both.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
dimensional stability
ability of a resilient floor covering to retain its original linear dimensions after exposure to heat, determined
by measuring the linear dimensional change in machine direction or across machine direction
Note 1 to entry: Retaining original linear dimensions includes no elongation or shrinking.
3.2
curling
vertical deformation
vertically concave (+) or convex (-) deformation from the horizontal
3.3
concave deformation
type of curling (vertical deformation) appearing as uplifted top surface at the outer edge of the specimen;
given as positive value (+)
3.4
convex deformation
type of curling (vertical deformation) appearing as uplifted, domed top surface in the centre of the specimen;
given as negative value (-)
ISO 23999:2025(en)
3.5
machine direction
MD
direction parallel to the length side of a floor covering manufactured in a continuous process
Note 1 to entry: For rectangular or squared cut specimens (e.g. tiles and planks) where the machine direction cannot
be determined, the direction of MD can be arbitrarily assigned for the test to enable differentiation from across
machine direction (AMD).
3.6
across machine direction
AMD
direction across to the length side of a floor covering manufactured in a continuous process
Note 1 to entry: For rectangular or squared cut specimens (e.g. tiles and planks) where the across machine direction
cannot be determined, the AMD can be arbitrarily assigned for the test to enable differentiation from machine
direction (MD).
4 Principle
4.1 General
Three test specimens are initially measured and then placed in an oven at an elevated temperature
which can cause dimensional changes and curl. After a specific period in the oven and subsequent time of
reconditioning, dimensional stability and the stability against vertical deformation (curling) are measured
again on the same test specimens.
4.2 Dimensional stability
The relative change in linear distance between the same marks or same specific locations of the top surface
layer of a test specimen, measured after exposure to a heat treatment and reconditioning. Depending on
the size of the specimen and the structure of the surface, different measuring devices can therefore be
appropriate.
As a special interest case, the change of linear dimensions can be determined on hot test specimens, meaning
before reconditioning. As this does not affect the measurement of dimensional stability and curling, it may
be determined as an intermediate result on the same test specimens (see Annex A).
4.3 Curling (vertical deformation)
Curling is measured at the highest peaks of the test specimens, possibly occurring after the specified heat
treatment in an oven at an elevated temperature and reconditioning in a normal conditioned climate.
An initial vertical deformation of the test specimen (before the exposure to heat) may be measured (see
Figure 7).
5 Apparatus
5.1 Oven
The oven shall be thermostatically controlled and ventilated, capable of being maintained at a uniform
temperature with maximum deviations of ±2 °C.
The oven shall allow for specimens to be placed inside in a way that ensures that radiation from the heating
elements does not directly reach the test specimens or support plates (see 5.2). Therefore, the distance
between the support plates and the vertical walls of the oven shall be more than 50 mm and the vertical
distance between the support plates and between the plates and the oven ceiling and base shall be more
than 100 mm.
ISO 23999:2025(en)
5.2 Support plates
The support plates on which the specimens will be placed for the test shall be of metal, e.g. aluminium or
stainless steel, and 2,0 mm ± 0,5 mm in thickness. The overall length and width of the support plates shall
be of dimensions larger than the test specimen. Ensure that the support plates are kept smooth and polished
so that surface friction does not interfere with free shrinkage or growth of the test specimens. The plates
shall be flat and free of convex or concave distortion and fully support the specimen (e.g. a wire rack support
plate is not acceptable.).
6 Measuring devices
6.1 Measurement devices for determination of curling (vertical deformation)
The measuring equipment can be any appropriate apparatus or device capable of measuring small distances
vertical from the support plate (see 5.2) with a minimum resolution of the display accuracy or graduation of
±0,1 mm and without influencing the test specimens by any kind of load from the test device itself.
This may include:
— a laser measuring device;
— other optical measuring devices;
— tactile measuring devices (e.g. pillar-mounted drop gauge device, feeler gauges or a micrometer).
6.2 Measurement devices for determination of linear dimension changes
6.2.1 General
All used measuring equipment shall measure with a minimum resolution of the display accuracy or
graduation of at least ±0,02 mm.
The measuring equipment may include:
— an optical bench for non-contact dimensional measurements between two marks on the top surface (for
example scores which are carefully made in the surface); or
— callipers; or
— a block and dial set-up (see 6.2.4) as shown in Figures 2, 3 and 4 for tactile measurement at the outer edge
of the specimen top layer.
For many types of optical benches, ensure that the test specimen is properly seated against the base
horizontal index guide when a specific measurement is being taken, otherwise test specimens with concave
or convex edges can be read incorrectly.
For ready shaped floor covering elements (e.g. tiles and planks), the block and dial gauge apparatus is
appropriate. For test specimens prepared from sheet or roll material, equipment shall be used which take
measures from the top surface.
6.2.2 Scoring device
For measurements with an optical bench (see 6.2.1) a scoring device, e.g. a single edge razor blade, scalpel
or scribe point, may be used to make marks in the top surface of test specimens made from sheet or roll
material or optionally tiles and planks.
6.2.3 Rigid steel plate
Optional auxiliary device to help flatten test specimens from sheet or roll material or optionally-tiles and
planks with a concave deformation or with a convex deformation. A rigid plate of steel, squared and finished,

ISO 23999:2025(en)
of dimensions 240 mm × 240 mm with holes to see the measuring marks (examples are shown in Figures 1
and 6) on the top surf
...