ISO/FDIS 4918

• Abstract:

  ISO 4918:2016 specifies methods for determining the change of appearance and stability of a textile floor covering or any damage caused by detachment of layers, opening of joints, or crazing of a resilient or laminate floor covering under the movement of a castor chair.

• Status: Not Published
• ICS: 97.150 - Floor coverings
• Technical Committee: ISO/TC 219 - Floor coverings
• Drafting Committee: ISO/TC 219 - Floor coverings
• Current Stage: 5020 - FDIS ballot initiated: 2 months. Proof sent to secretariat
• Start Date: 05-Aug-2026
• Completion Date: 05-Aug-2026

• Consolidates: FprEN ISO 4918 - Resilient, textile, laminate and modular mechanical locked floor coverings - Castor chair test (ISO/FDIS 4918:2026)
• Effective Date: 12-Feb-2026
• Revises: ISO 4918:2016 - Resilient, textile and laminate floor coverings — Castor chair test
• Effective Date: 03-Sep-2022
• Revises: ISO 4918:2016/Amd 1:2018 - Resilient, textile and laminate floor coverings — Castor chair test — Amendment 1: Surface hardness
• Effective Date: 03-Sep-2022

Overview

ISO/FDIS 4918:2025 sets out standardized testing methods for evaluating the durability, appearance change, and structural stability of resilient, textile, laminate, and modular mechanical locked floor coverings subjected to the repeated action of a castor (swivel) chair. Developed by the International Organization for Standardization (ISO) Technical Committee 219, the standard is integral in assessing floor covering performance in environments where rolling loads are common, ensuring product reliability and user satisfaction.

The test simulates long-term exposure to castor chairs by moving them over the surface for a prescribed number of cycles. It observes the resulting wear, any detachment of layers, opening of joints, cracks, or the formation of surface crazing. ISO 4918 plays a critical role for manufacturers, designers, facility managers, and end-users aiming to select or specify floor coverings that withstand the rigors of office or commercial environments with castor chair traffic.

Key Topics

• Scope of Testing: Applies to textile, resilient (e.g., vinyl), laminate, and modular mechanical locked floor coverings, covering both traditional lay and mechanical locking installation systems.
• Testing Procedure: Outlines detailed preparation, cycle count, specimen mounting, use of specific castor types, and standard conditions for temperature and humidity.
• Assessment Methods: Provides criteria for evaluating the change in visual appearance (including color and texture), as well as integrity (delamination, layer separation, joint opening, and crazing).
• Equipment Specification:
  • Rotating test platform and castor assembly with specific dimensions and loading.
  • Type H (hard tread) and Type W (soft tread) castors as per EN 12529.
  • Use of suction devices to remove abrasion debris.
• Results and Reporting: Requires a structured test report documenting appearance change, structural damage, and measurement data following testing protocols.

Applications

Implementing ISO 4918 is essential for:

• Manufacturers: Product development, certification, and quality assurance of flooring designed for office, institutional, and heavy-use commercial spaces.
• Specifiers and Architects: Ensuring flooring products meet durability standards for castor chair use before installation in projects such as office buildings, schools, and healthcare facilities.
• Facility Managers: Selecting flooring that resists wear, maintains appearance, and ensures safety under rolling loads.
• Testing Laboratories: Independent verification of floor covering performance and compliance for market access or regulatory requirements.
• Purchasers and End Users: Making informed choices based on verified durability under real-world conditions.

Floor coverings passing ISO 4918 testing demonstrate resilience against castor action, reducing maintenance costs, prolonging product life, and enhancing occupant satisfaction in high-traffic installations.

Related Standards

ISO 4918 references and aligns with several key international and European standards for floor coverings and testing, including:

• ISO 139: Standard atmospheres for conditioning and testing of textiles.
• ISO 1957: Methods for selection and cutting of textile floor covering specimens.
• ISO 2424: Floor coverings vocabulary.
• ISO 9405 / ASTM D7330: Assessment of changes in appearance in pile floor coverings.
• EN 12466: Vocabulary for resilient floor coverings.
• EN 12529: Requirements for castors used on furniture, including swivel chairs.
• EN 16511: Specifications for modular mechanical locked floor coverings (MMF).

Compliance with ISO/FDIS 4918 enhances product marketability, meets regulatory expectations, and aligns with global best practices for floor covering quality and performance in castor chair environments.

---

Keywords: ISO 4918, castor chair test, resilient floor covering, textile floor covering, laminate flooring, modular mechanical locked flooring, flooring durability, appearance change, floor covering testing, commercial flooring standards, office flooring abrasion, mechanical locking systems, ISO flooring standards.

FINAL DRAFT
International
Standard
ISO/TC 219
Resilient, textile, laminate and
Secretariat: NBN
modular mechanical locked floor
Voting begins on:
coverings — Castor chair test
2026-08-05
Revêtements de sol textiles, résilients ou stratifiés — Essai à
Voting terminates on:
l'appareil à roulettes
2026-09-30
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 SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/CEN PARALLEL PROCESSING LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
FINAL DRAFT
International
Standard
ISO/TC 219
Resilient, textile, laminate and
Secretariat: NBN
modular mechanical locked floor
Voting begins on:
coverings — Castor chair test
Revêtements de sol textiles, résilients ou stratifiés — Essai à
Voting terminates on:
l'appareil à roulettes
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 SUPPOR TING DOCUMENTATION.
© ISO 2026
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/CEN PARALLEL PROCESSING
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Materials . 6
7 Sampling . 7
7.1 Textile floor coverings .7
7.2 Resilient floor coverings without mechanical locking system .7
7.3 Resilient, laminate and modular mechanical locked floor coverings with mechanical
locking systems . .8
8 Conditioning . 10
8.1 Textile floor coverings .10
8.2 Resilient, laminate and modular mechanical locked floor coverings .10
9 Procedure .10
9.1 Textile floor coverings .10
9.1.1 General .10
9.1.2 Mounting of the specimens .10
9.1.3 Verifications of the castors .10
9.1.4 Preparing of the apparatus .10
9.1.5 Test procedures .10
9.2 Resilient, laminate and modular mechanical locked floor coverings . 12
9.2.1 General . 12
9.2.2 Mounting of the specimen(s) . 12
9.2.3 Verification of the castors . 13
9.2.4 Preparing the apparatus . 13
9.2.5 Test procedure. 15
10 Assessment . .15
10.1 Textile floor coverings . 15
10.1.1 General . 15
10.1.2 Test A — Structural integrity assessment .16
10.1.3 Test A — Appearance retention assessment .16
10.1.4 Test B — Colour change assessment .16
10.1.5 Test C — Structural integrity assessment .16
10.2 Resilient, laminate and modular mechanical locked floor coverings .17
11 Calculations and expression of results . 17
11.1 Textile floor coverings .17
11.1.1 General .17
11.1.2 Castor index .17
11.2 Resilient, laminate and modular mechanical locked floor coverings .17
12 Test report . 17
12.1 General .17
12.2 Textile floor coverings .18
12.3 Resilient, laminate and modular mechanical locked floor coverings .18
Annex A (informative)  . 19

iii
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 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
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 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 third edition cancels and replaces the second edition (ISO 4918:2016/Amd 1:2018), which has been
technically revised.
The main changes are as follows:
— revision of information regarding the machine;
— revision of information regarding the fasting methods;
— addition of methods for testing modular mechanical locked floor coverings (MMF).
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 www.iso.org/members.html.

iv
FINAL DRAFT International Standard ISO/FDIS 4918:2026(en)
Resilient, textile, laminate and modular mechanical locked
floor coverings — Castor chair test
1 Scope
This document specifies methods for determining the change of appearance and stability of a textile floor
coverings or any damage caused by detachment of layers, opening of joints, cracks, or crazing of a resilient,
laminate or modular mechanical locked floor coverings under the movement of a swivel castor chair.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 139:2005/AMD1:2 011, Textiles — Standard atmospheres for conditioning and testing
ISO 1957, Machine-made textile floor coverings — Selection and cutting of specimens for physical tests
ISO 2424, Textile floor coverings — Vocabulary
ISO 9405, Textile floor coverings — Assessment of changes in appearance
EN 12466, Resilient floor coverings — Vocabulary
EN 12529, Castors and wheels — Castors for furniture — Castors for swivel chairs — Requirements
EN 16511, Modular mechanical locked floor coverings (MMF) — Specification, requirements and test method for
multilayer modular panels for floating installation
ASTM D7330, Standard Test Method for Assessment of Surface Appearance Change in Pile Floor Coverings Using
Standard Reference Scales
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2424, EN 16511, EN 12466 and the
following 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
crazing
fine random cracks apparent in the surface of a floor coverings, generally caused by an applied stress acting
on the surface
Note 1 to entry: Applied stress can include, for example, sustained exposure to a rolling load.

4 Principle
A floor covering comprising one or more individual pieces with or without joint and treated or welded where
necessary, is submitted for a prescribed number of cycles to the action of three castors. The castors move in
epicyclical paths with multiple changes of direction, stops and starts, and the frequency of passage varies
from area to area.
For textile floor coverings, three different assessment methods are specified.
a) The change in appearance shall be assessed after 5 000 cycles and 25 000 cycles in accordance with
ISO 9405 (Test A) or ASTM D7330.
b) The change in colour shall be assessed by means of grey scales after 750 cycles in accordance with
ISO 9405 (Test B) or ASTM D7330.
c) The extent of deterioration shall be assessed after 10 000 cycles or 25 000 cycles (Test C).
For resilient, laminate or modular mechanical locked floor coverings, any damage to the specimen caused
during testing and visible as detachment of layers, opening of joints, cracking or crazing shall be assessed.
5 Apparatus
5.1 Rotating test platform
The rotating test platform on which the test specimen or the specimen support (5.9) together with the test
specimen is placed shall have a diameter of at least 795 mm (circular platform) or platform with a length
and width of at least 1 000 mm (square platform).
5.2 Castor assembly
This assembly comprises a vertical shaft, set in a bearing, and a plate on which the castors are mounted (see
Figure 1, item 1). This castor assembly is offset at a distance of (198 ± 1) mm from the centre of the rotating
test platform.
The three castors are each arranged concentrically at 120° intervals around the centre of the plate at a
distance of (130 ± 1) mm from the centre of the plate, and are free to rotate, so that they follow the rotation
of the castor assembly.
The tested area of the specimen is determined by the distance between the axes of revolution of the castor
chair assembly and the specimen table and by the distance of the castors from the centre of the plate. This
area is approximately 0,3 m .
Dimensions in millimetres
Key
1 shaft
2 distance >3 mm
3 load and or drive plate
4 castor mounting plate
5 chain
6 specimen
7 suction device with height regulation
8 rotating test platform
9 specimen support
Figure 1 — Typical castor chair apparatus
The castor assembly is loaded with additional weights to achieve a total load of (90 ± 2) kg equally divided
over the three castors.
The distance (under load) between the castor mounting plate and either the load or drive plate, or both,
shall be >3 mm.
Key
1 castor assembly
Figure 2 — Path of castors
5.3 Drive mechanism
The drive to the rotating test platform and to the castor assembly is interlocked and fitted with a reversing
mechanism. The number of cycles is set by means of a pre-set counter. The rotational speed of the rotating
-1 -1
platform shall be (19 ± 2) min and that of the castor assembly (50 ± 5) min .
After (180 ± 20) s of rotation, the platform shall stop and remain in the stop position for (5 ± 2) s, after which
time the direction of rotation of the rotating platform shall reverse.
The relationship between the rotational speed of the test platform and that of the castor assembly causes a
sharp reverse movement of the castors of about 160° at a point close to the outer edge of the stressed area
(see Figure 2).
5.4 Suction device
The suction capacity of the vacuum cleaner and the height of the suction device (see Figure 1, item 7) should
be able to remove all abrased material or dust in a way that the surface of the test specimen is always kept
clean during the test. A suction capacity of (30 ± 5) l/s is recommended to reach this requirement.
5.5 Castors
5.5.1 General
Single-wheel swivel castors shall be used having the following dimensions (see Figure 3):
a) diameter of the wheel: (50 ± 2) mm;
b) width of the wheel: (20 ± 2) mm;
c) radius of curvature, R, of castor tread: nominal 130 mm;
d) crank distance: (32 ± 2) mm.
The distance between any two castor mountings shall be (225 ± 5) mm.

Dimensions in millimetres
Figure 3 — Single-wheel swivel castors (nominal dimensions in mm)
1)
5.5.2 Type H castors conforming to EN 12529, suitable for resilient, textile, laminate and modular
mechanical locked floor coverings.
Type H castors shall have plain wheels and a hard tread. The castor treads shall be made from polyamide,
with a surface hardness of (95 ± 5) Shore A and shall be stored under exclusion of light. The wheels
shall be one colour over their entire surface. The surface of the castors shall be replaced after maximum
2 000 000 cycles of the rotating test platform. It is advisable to replace them all three.
The castor treads shall be examined after each test to verify that they are still smooth, without any deep
scoring or encrusted hard particles. The tread shall be replaced if the dimensions of the wheel fall outside
the tolerances given in 5.5.1.
2)
5.5.3 Type W castors conforming to EN 12529, suitable for resilient, laminate and modular mechanical
locked floor coverings.
Type W castors shall have resilient-tyred wheels and a soft tread. The castor treads shall be made from
polyurethane, with a surface hardness of (90 ± 5) Shore A and shall be stored under exclusion of light. The
surface of the castors shall be replaced after maximum 1 000 000 cycles of the test platform. It is advisable
to replace them all three.
1) An example of a commercially available Type H castor is from Quanz-Machinenbau GmbH. This information is given
for the convenience of users of this document and does not constitute an endorsement by ISO of this product.
2) An example of a commercially available castor product “Type W” is “Maxtech UAK050x20-Ø6,1” from TENTE
International GmbH. This information is given for the convenience of users of this document and does not constitute an
endorsement by ISO of this product.

The castor treads shall be examined after each test to verify that they are still smooth, without any deep
scoring or encrusted hard particles. The tread shall be replaced if the dimensions of the wheel fall outside
the tolerances given in 5.5.1.
5.6 Lifting device, to raise the castor assembly above the test platform when the apparatus is stationary.
5.7 Cycle counter, for setting the number of cycles of the test platform.
5.8 Fastening system
Flooring specimens shall be securely held in place on the specimen support (5.9) using glue, tape, or
other suitable means. For loose-laid installations, the panels, sheets and tiles shall be secured at the outer
perimeter using tape, which may include a flooring product and an underlayment, a hold down ring, an outer
ring, hold down clamps (see Annex A) or other suitable means to prevent specimens, from shifting during
the test. The vertical force should
...

Modular mechanical locked floor coverings
ISO/DIS FDIS 4918:2025(en)
ISO/TC 219/WG 4
Secretariat: NBN
Date: 2026-05-0307-22
Resilient, textile, laminate and modular mechanical locked floor
coverings — Castor chair test
Revêtements de sol textiles, résilients ou stratifiés — Essai à l'appareil à roulettes
FDIS stage
TThhiiss dr draafftt i iss susubbmmiitttteed d ttoo aa ppaarraallellel l vvoottee i inn IISSOO,, CCEEN.N.

ISO/DIS FDIS 4918:2025(E2026(en)
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
EmailE-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO/DIS FDIS 4918:20252026(en)
Contents
Foreword . iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
6 Materials. 9
7 Sampling . 9
7.1 Textile floor coverings . 9
7.2 Resilient floor coverings without mechanical locking system . 10
7.3 Resilient, laminate and modular mechanical locked floor coverings with mechanical
locking systems . 12
8 Conditioning . 14
8.1 Textile floor coverings . 14
8.2 Resilient, laminate and modular mechanical locked floor coverings . 14
9 Procedure . 14
9.1 Textile floor coverings . 14
9.2 Resilient, laminate and modular mechanical locked floor coverings . 16
10 Assessment . 21
10.1 Textile floor coverings . 21
10.2 Resilient, laminate and modular mechanical locked floor coverings . 23
11 Calculations and expression of results . 24
11.1 Textile floor coverings . 24
11.2 Resilient, laminate and modular mechanical locked floor coverings . 24
12 Test report . 24
12.1 General . 24
12.2 Textile floor coverings . 25
12.3 Resilient, laminate and modular mechanical locked floor coverings . 25
Annex A (informative) . 26

iii
ISO/DIS FDIS 4918:2025(E2026(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 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
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 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 third edition cancels and replaces the second edition (ISO 4918:2016/Amd 1:2018), which has been
technically revised.
The main changes are as follows:
— — revision of information regarding the machine;
— — revision of information regarding the fasting methods;
— — addition of methods for how to testtesting modular mechanical locked floor coverings (MMF).
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 www.iso.org/members.html.
iv
DRAFT International Standard ISO/DIS 4918:2025(en)

Resilient, textile, laminate and modular mechanical locked floor
coverings — Castor chair test
1 Scope
This document specifies methods for determining the change of appearance and stability of a textile floor
coverings or any damage caused by detachment of layers, opening of joints, cracks, or crazing of a resilient,
laminate or modular mechanical locked floor coverings under the movement of a swivel castor chair.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 139:2005/AMD1:2011, Textiles — Standard atmospheres for conditioning and testing
ISO 1957, Machine-made textile floor coverings — Selection and cutting of specimens for physical tests
ISO 2424, Textile floor coverings — Vocabulary
ISO 9405, Textile floor coverings — Assessment of changes in appearance
EN 12466, Resilient floor coverings — Vocabulary
EN 12529, Castors and wheels — Castors for furniture — Castors for swivel chairs — Requirements
EN 16511, Modular mechanical locked floor coverings (MMF) — Specification, requirements and test method for
multilayer modular panels for floating installation
ASTM D7330, Standard Test Method for Assessment of Surface Appearance Change in Pile Floor Coverings Using
Standard Reference Scales
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2424, EN 16511 and, EN 12466 and
the following 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
3.1
Crazing
ISO/DIS FDIS 4918:2025(E2026(en)
crazing
fine random cracks apparent in the surface of a floor coverings, generally caused by an applied stress acting
on the surface e.g.
Note 1 to entry: Applied stress can include, for example, sustained exposure to a rolling load.
4 Principle
A floor covering comprising one or more individual pieces with or without joint and treated or welded where
necessary, is submitted for a prescribed number of cycles to the action of three castors. The castors move in
epicyclical paths with multiple changes of direction, stops and starts, and the frequency of passage varies from
area to area.
For textile floor coverings, three different assessment methods are specified.
a) a) The change in appearance shall be assessed after 5 000 cycles and 25 000 cycles in accordance
with ISO 9405 (Test A) or ASTM D7330.
b) b) The change in colour shall be assessed by means of grey scales after 750 cycles in accordance
with ISO 9405 (Test B) or ASTM D7330.
c) c) The extent of deterioration shall be assessed after 10 000 cycles or 25 000 cycles (Test C).
For resilient, laminate or modular mechanical locked floor coverings, any damage to the specimen caused
during testing and visible as detachment of layers, opening of joints, cracking or crazing shall be assessed.
5 Apparatus
5.1 5.1 Rotating test platform
The rotating test platform on which the test specimen or the specimen support (5.9(5.9)) together with the
test specimen is placed shall have a diameter of at least 795 mm (circular platform) or platform with a length
and width of at least 1 000 mm (square platform).
5.2 5.2 Castor assembly
This assembly comprises a vertical shaft, set in a bearing, and a plate on which the castors are mounted (see
Figure 1, item 1). This castor assembly is offset at a distance of (198 ± 1) mm from the centre of the rotating
test platform.
The three castors are each arranged concentrically at 120° intervals around the centre of the plate at a distance
of (130 ± 1) mm from the centre of the plate, and are free to rotate, so that they follow the rotation of the castor
assembly.
The tested area of the specimen is determined by the distance between the axes of revolution of the castor
chair assembly and the specimen table and by the distance of the castors from the centre of the plate. This
area is approximately 0,3 m .
ISO/DIS FDIS 4918:20252026(en)

Dimensions in millimetres
ISO/DIS FDIS 4918:2025(E2026(en)

Key
1 shaft
2 distance >3 mm
3 load and or drive plate
4 castor mounting plate
5 chain
6 specimen
7 suction device with height regulation
8 rotating test platform
9 specimen support
Figure 1 — Typical castor chair apparatus

The castor assembly is loaded with additional weights to achieve a total load of (90 ± 2) kg equally divided
over the three castors.
The distance (under load) between the castor mounting plate and either the load and or drive plate, or both,
shall be >3 mm.
ISO/DIS FDIS 4918:20252026(en)

Key
1 castor assembly
Figure 2 — Path of castors
5.3 5.3 Drive mechanism
The drive to the rotating test platform and to the castor assembly is interlocked and fitted with a reversing
mechanism. The number of cycles is set by means of a pre-set counter. The rotational speed of the rotating
-1 -1
platform shall be (19 ± 2) min and that of the castor assembly (50 ± 5) min .
After (180 ± 20) s of rotation, the platform shall stop and remain in the stop position for (5 ± 2) s, after which
time the direction of rotation of the rotating platform shall reverse.
The relationship between the rotational speed of the test platform and that of the castor assembly causes a
sharp reverse movement of the castors of about 160° at a point close to the outer edge of the stressed area
(see Figure 2).
Field Code Changed
5.4 5.4 Suction device
The suction capacity of the vacuum cleaner and the height of the suction device (see Figure 1, item 7) should
be able to remove all abrased material or dust in a way that the surface of the test specimen is always kept
clean during the test. A suction capacity of (30 ± 5) l/s is recommended to reach this requirement.
5.5 5.5 Castors
ISO/DIS FDIS 4918:2025(E2026(en)
5.5.1 5.5.1 General
Single-wheel swivel castors shall be used having the following dimensions (see Figure 3):
Field Code Changed
a) a) diameter of the wheel: (50 ± 2) mm;
b) b) width of the wheel: (20 ± 2) mm;
c) c) radius of curvature, R, of castor tread: nominal 130 mm;
d) d) crank distance: (32 ± 2) mm.
The distance between any two castor mountings shall be (225 ± 5) mm.
ISO/DIS FDIS 4918:20252026(en)
Dimensions in millimetres
ISO/DIS FDIS 4918:2025(E2026(en)
Figure 3 — Single-wheel swivel castors (nominal dimensions in mm)
11)
5.5.2 5.5.2 Type H castors conforming to EN 12529, suitable for resilient, textile, laminate and modular
mechanical locked floor coverings.
Type H castors shall have plain wheels and a hard tread. The castor treads shall be made from polyamide, with
a surface hardness of (95 ± 5) Shore A and shall be stored under exclusion of light. The wheels shall be one
colour over their entire surface. The surface of the castors shall be replaced after maximum 2 000 000 cycles
of the rotating test platform. It is advisable to replace them all three.
The castor treads shall be examined after each test to verify that they are still smooth, without any deep
scoring or encrusted hard particles. The tread shall be replaced if the dimensions of the wheel fall outside the
tolerances given in 5.5.15.5.1.
22)
5.5.3 5.5.3 Type W castors conforming to EN 12529, suitable for resilient, laminate and modular
mechanical locked floor coverings.
Type W castors shall have resilient-tyred wheels and a soft tread. The castor treads shall be made from
polyurethane, with a surface hardness of (90 ± 5) Shore A and shall be stored under exclusion of light. The
surface of the castors shall be replaced after maximum 1 000 000 cycles of the test platform. It is advisable to
replace them all three.
The castor treads shall be examined after each test to verify that they are still smooth, without any deep
scoring or encrusted hard particles. The tread shall be replaced if the dimensions of the wheel fall outside the
tolerances given in 5.5.15.5.1.
5.6 5.6 Lifting device, to raise the castor assembly above the test platform when the apparatus is
stationary.
5.7 5.7 Cycle counter, for setting the number of cycles of the test platform.
5.8 5.8 Fastening system
Flooring specimens shall be securely held in place on the specimen support (5.9(5.9)) using glue, tape, or other
suitable means. For loose-laid installations, the panels, sheets and tiles shall be secured at the outer perimeter
using tape, which may include a flooring product and an underlayment, a hold down ring, an outer ring, hold
down clamps (see Annex AAnnex A)) or other suitable means to prevent specimens, from shifting during the
test. The vertical force should be reduced to a minimum.
The fixing must ensure that no part of the assembly can move against any other part of the assembly, meaning
no movement between the support and the underlay and between the underlay and the floor coverings and
between the elements of the floor coverings. The vertical force should be reduced to a minimum so that
movement is just prevented and there is no vertical deformation of the sample.

An example of a commercially available Type H castor is from Quanz-Machinenbau GmbH. This information is given for
the convenience of users of this document and does not constitute an endorsement by ISO of this product.
1)
An example of a commercially available Type H castor is from Quanz-Machinenbau GmbH. This information is given for
the convenience of users of this document and does not constitute an endorsement by ISO of this product.
An example of a commercially available castor product “Type W” is “Maxtech UAK050x20-Ø6,1” from TENTE
International GmbH. This information is given for the convenience of users of this document and does not constitute an
endorsement by ISO of this product.
2)
An example of a commercially available castor product “Type W” is “Maxtech UAK050x20-Ø6,1” from TENTE
International GmbH. This information is given for the convenience of users of this document and does not constitute an
endorsement by ISO of this product.
ISO/DIS FDIS 4918:20252026(en)
5.9 5.9 Specimen support
The specimen support shall be placed on a plate of rigid plastic [e.g. poly(methyl methacrylate)] or suitable
substrate with a thickness of at least 5 mm till 30 mm and approximately the same diameter as the rotating
platform (5.1(5.1)) or about the same dimensions as the square platform (5.1(5.1).).
The specimen support itself shall be laid on the rotating test platform and holes made in the support in order
to engage the platform studs, to prevent slippage.
5.10 5.10 External vacuum cleaner, for textile floor coverings, resilient, laminate and modular
mechanical locked floor coverings.
5.11 5.11 Illumination device (not to be used for textile floor coverings)
Illumination shall give an illuminance across the table of (1 500 ± 300) lx and in such a way as to illuminate
the specimen vertically from above and allow uninterrupted viewing of the specimen. The surroundings shall
be neutral and darkened.
The illuminance shall be checked prior to each assessment series by the use of a lux meter.
5.12 5.12 Thickness gauge, of 0,50 mm.
5.13 5.13 Steel ruler, with a length of 500 mm.
6 Materials
6.1 6.1 White cotton, in pad or paper form.
6.2 6.2 Adhesive scrim, double-sided adhesive tape or adhesive.
6.3 6.3 Denatured ethanol
6.4 6.4 Neutral cleansing agent
7 Sampling
7.1 Textile floor coverings
Take specimens from the sample in accordance with ISO 1957.
Prepare the specimens as follows.
a) a) For Test A:
Cut from the sample either three semi-circles or six quadrants with a radius of 350 mm ± 10 mm. The
straight side of the semi-circles or the quadrant edges shall be either parallel to or at right angles to the
direction of manufacture. Cut also a reference specimen of 200 mm × 200 mm. In all cases, mark the
direction of manufacture.
If testing only one textile floor coverings, the spare specimen that will not be used in the evaluation phase
is required to fill the gap left by removal of the 5 000-cycle specimen (see 9.1.5.29.1.5.2).).
b) b) For Test B:
If possible, test samples of different batches/colour during each test.
ISO/DIS FDIS 4918:2025(E2026(en)
Cut from each batch/colour either one semi-circle or one quadrant of radius 350 mm ± 10 mm. Cut also a
reference specimen, with dimensions of 200 mm × 200 mm. In all cases, mark the specimens with the
direction of manufacture.
If testing only one textile floor coverings, the spare samples that will not be used in the evaluation phase
are required to fill in the gaps.
c) c) For Test C:
Cut two semi-circles or four quadrants from each sample with a radius of 350 mm ± 10 mm.
If testing only one textile floor coveringscovering, the spare sample that will not be used in the evaluation
phase is required to fill the gap left by removal of the 10 000-cycle specimen (see 9.1.5.59.1.5.5).).
7.2 Resilient floor coverings without mechanical locking system
Take a representative sample from th
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