prEN 18234

SLOVENSKI STANDARD
01-december-2025
Modularne mehansko zaklenjene talne obloge za plavajoče polaganje - Podlage -
Specifikacije, zahteve in preskusne metode
Modular mechanical locked floor coverings for floating installation - Underlays -
Specification, requirements and test methods
Modulare mechanisch verriegelnde Bodenbeläge für die schwimmende Verlegung -
Unterlagsmaterialien - Spezifikation, Anforderungen und Prüfverfahren
Revêtements de sol modulaires à verrouillage mécanique (MMF) - Sous-couches -
Spécifications, exigences et méthodes d'essai
Ta slovenski standard je istoveten z: prEN 18234
ICS:
97.150 Talne obloge Floor coverings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2025
ICS 97.150
English Version
Modular mechanical locked floor coverings for floating
installation - Underlays - Specification, requirements and
test methods
Revêtements de sol modulaires à verrouillage Modulare mechanisch verriegelnde Bodenbeläge für
mécanique (MMF) - Sous-couches -Spécifications, die schwimmende Verlegung - Unterlagsmaterialien -
exigences et méthodes d'essai Spezifikation, Anforderungen und Prüfverfahren
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 134.
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.

This draft European Standard 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, Türkiye 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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 18234:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 5
3.7 Types of cores . 6
4 Requirements . 6
4.1 General. 6
4.2 General requirements . 7
4.3 Additional technical requirements . 8
4.4 Testing . 9
4.4.1 General. 9
4.4.2 Thickness (t) . 9
4.4.3 Punctual conformability (PC) . 10
4.4.4 Compressive strength (CS) . 10
4.4.5 Dynamic load (DL and DL ) resistance . 10
25 75
4.4.6 Compressive Creep (CC) resistance . 10
4.4.7 Thermal resistance (R) . 10
4.4.8 Water vapour resistance (SD) . 11
4.4.9 Resistance to impact by large diameter ball (RLB) . 11
4.4.10 Emission of formaldehyde . 11
4.4.11 Emission of VOCs . 11
4.4.12 Area weight (AW) . 11
4.4.13 Reaction to fire (RTF) . 11
4.4.14 Impact sound (IS) . 12
4.4.15 Radiated walking sound (RWS) . 12
5 Marking and labelling . 13
6 Test Report . 13
Annex A (normative) Determination of thickness, length, width, squareness, flatness, punctual
conformability, compressive strength, compressive creep resistance, dynamic load
resistance and area weight . 14
Bibliography . 21

European foreword
This document (prEN 18234:2025) has been prepared by Technical Committee CEN/TC 134 “Resilient,
textile, laminate and modular mechanical locked floor coverings”, the secretariat of which is held by NBN.
This document is currently submitted to the CEN Enquiry.
1 Scope
This document specifies test methods for the determination of the technical characteristics of underlays
under modular mechanical locked floor coverings. It can be used to compare different underlays and to
encourage the consumer to make an informed choice. It also specifies requirements for marking and
packaging.
Underlays pre-attached to the flooring coverings are not covered by this document.
This document is not applicable to the performance of the floor covering system. This will be checked
separately depending on the used floor covering.
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.
EN 824, Thermal insulating products for building applications — Determination of squareness
EN 1264-3, Water based surface embedded heating and cooling systems — Part 3: Dimensioning
EN 12086, Thermal insulating products for building applications — Determination of water vapour
transmission properties
EN 12664, Thermal performance of building materials and products — Determination of thermal resistance
by means of guarded hot plate and heat flow meter methods — Dry and moist products of medium and low
thermal resistance
EN 12667, Thermal performance of building materials and products — Determination of thermal resistance
by means of guarded hot plate and heat flow meter methods — Products of high and medium thermal
resistance
EN 13238, Reaction to fire tests for building products — Conditioning procedures and general rules for
selection of substrates
EN 13329, Laminate floor coverings — Specifications, requirements and test methods
EN 13501-1, Fire classification of construction products and building elements — Part 1: Classification
using data from reaction to fire tests
EN 13793, Thermal insulating products for building applications — Determination of behaviour under
cyclic loading
EN 16205:2020, Laboratory measurement of walking noise on floors
EN 16516, Construction products — Assessment of release of dangerous substances — Determination of
emissions into indoor air
EN ISO 717-2, Acoustics — Rating of sound insulation in buildings and of building elements — Part 2:
Impact sound insulation (ISO 717-2)
EN ISO 868, Plastics and ebonite — Determination of indentation hardness by means of a durometer (Shore
hardness) (ISO 868)
EN ISO 1923, Cellular plastics and rubbers — Determination of linear dimensions (ISO 1923)
EN ISO 10140-3, Acoustics — Laboratory measurement of sound insulation of building elements — Part 3:
Measurement of impact sound insulation (ISO 10140-3)
EN ISO 10140-5:2021, Acoustics — Laboratory measurement of sound insulation of building elements —
Part 5: Requirements for test facilities and equipment (ISO 10140-5:2021)
EN ISO 11925-2, Reaction to fire tests — Ignitability of products subjected to direct impingement of
flame — Part 2: Single-flame source test (ISO 11925-2)
EN ISO 15106-2, Plastics — Film and sheeting — Determination of water vapour transmission rate —
Part 2: Infrared detection sensor method(ISO 15106-2)
EN ISO 15106-3, Plastics — Film and sheeting — Determination of water vapour transmission rate —
Part 3: Electrolytic detection sensor method(ISO 15106-3)
EN ISO 16000-11, Indoor air — Part 11: Determination of the emission of volatile organic compounds
from building products and furnishing — Sampling, storage of samples and preparation of test
specimens(ISO 16000-11)
EN ISO 16534, Thermal insulating products for building applications — Determination of compressive
creep(ISO 16534)
EN ISO 29465, Thermal insulating products for building applications — Determination of length and
width(ISO 29465)
EN ISO 29466, Thermal insulating products for building applications — Determination of thickness(ISO
29466)
EN ISO 29468, Thermal insulating products for building applications — Determination of flatness(ISO
29468)
EN ISO 29469, Thermal insulating products for building applications — Determination of compression
behaviour(ISO 29469)
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
modular mechanical locked floor covering
MMF
floor covering as described in EN 16511:2023+A1:2025, EN ISO 20326 or EN 17142
3.2
underlay
layer placed between a continuous support and floor covering added to obtain specific requirements
Note 1 to entry: Vapour control layers and underfloor heating and/or cooling layers are not an underlay.
3.3
vapour control layer
additional layer which only function is to limit the passage of water vapour in the floor covering
3.4
floor covering system
laid floors consisting of MMF and underlay
3.5
reference floor covering
monolithic seamless panel with no pre-attached underlay, having a nominal thickness of (7,0 ± 0,2) mm
and a size of (2,0 ± 0,1) m x (2,4 ± 0,1) m in accordance with EN 13329, class 23/31 and produced by the
DPL method with melamine backing, and with an HDF core board with a density of (850 ± 50) kg/m
Note 1 to entry: This reference floor covering can be retrieved from EPLF (http://www.eplf.com).
3.6
substrate
structural layer on which the floor covering system is installed
3.7 Types of cores
3.7.1
wood-based core
core layer with a content of wood > 65 % by mass
3.7.2
non wood-based core
core layer which is not covered by 3.7.1
4 Requirements
4.1 General
The following Tables give an overview of the important key characteristics and requirements for the
underlay, depending on the exact application and products used. They have been determined for defined
scenarios (e.g. dynamic load by walking persons, moving castor chair, structural floor unevenness) and
by practical trials and measurements (e.g. 100 Pa is the approx. pressure of an unloaded floor covering
onto the underlay). Where needed, existing methods have been adapted. General requirements will give
satisfactory service for the majority of existing floor coverings. Please note that the information provided
by the floor manufacturer or supplier regarding the requirements for the use of underlays is binding and
overrules this document recommendations.
4.2 General requirements
All underlays shall fulfil the requirements of Table 1 or Table 2, if the tests are done by the specified test
methods.
Table 1 — General requirements for underlays for floor coverings with wood-based core
No. Characteristic Requirements/Tolerances Test method Subclause
1–1 Thickness (t) Measured thickness in mm EN ISO 29466 + A.3.1 4.4.2
Tolerance of declared thickness
a
(td): ± 15 % or ± 0,5 mm
1–2 Length (l) Measured length EN ISO 29465 + A.3.3
Tolerance of declared length (l ):
d
boards:  - 1 % + 5 %
rolls:  - 0 %
1–3 Width (w) Measured width EN ISO 29465 + A.3.2
Tolerance of declared width (w ):
d
- 1 % + 2,5 %
and of width variation
wmax – wmin ≤ 10 mm
1–4 Squareness (q) q < 5 mm/m EN 824 + A.3.4
max
1–5 Flatness (S) S < 2 mm/m EN ISO 29469 + A.3.5
max
1–6 Punctual PC ≥ 0,5 mm EN ISO 868 + A.3.6 4.4.3
conformability
(PC)
1–7 Compressive CS ≥ 10 kPa EN ISO 29469 + A.3.7 4.4.4
strength (CS)
1–8 Dynamic load DL ≥ 10,000 cycles EN 13793 + A.3.9 4.4.5
(DL ) resistance
a
Whichever gives the smallest numerical tolerances.
Table 2 — General requirements for underlays for floor coverings with non wood-based core
No. Characteristic Requirements/Tolerances Test method Subclause
1–1 Thickness (t) Measured thickness in mm EN ISO 29466 + A.3.1 4.4.2
Tolerance of declared thickness
a
(t ): ± 15 % or ± 0,5 mm
d
1–2 Length (l) Measured length EN ISO 29465 + A.3.2
Tolerance of declared length (ld):
boards:  - 1 % + 5 %
rolls:  - 0 %
1–3 Width (w) Measured width EN ISO 29465 + A3.3
Tolerance of declared width (w ):
d
- 1 % + 2,5 %
and of width variation
w – w ≤ 10 mm
max min
1–4 Squareness (q) q < 5 mm/m EN 824 + A.3.4
max
1–5 Flatness (S) S < 2 mm/m EN ISO 29468 + A.3.5
max
b
1–6 Punctual PC ≥ 0,5 mm EN ISO 868 + A.3.6 4.4.3
conformability
(PC)
1–7 Compressive CS ≥ 200 kPa EN ISO 29469 + A.3.7 4.4.4
strength (CS)
1–8 Dynamic load DL ≥ 10,000 cycles EN 13793 + A.3.9 4.4.5
(DL ) resistance
a
Whichever gives the smallest numerical tolerances.
b
Other, lower PC values can be necessary for certain floorings to maintain integrity of the flooring system
and can be agreed on between the manufacturer and the client.
4.3 Additional technical requirements
When reference is made to this standard the characteristics declared shall be determined according to
the test methods specified in Table 3.
Table 3 — Additional technical characteristics
No. Characteristic Note Test method Subclause
2–1 Compressive in kPa EN ISO 16534 + A.3.8 4.4.6
Creep resistance
(CC)
2–2 Thermal in m K/W EN 12667 or 4.4.7
resistance (R) EN 12664 at 24 °C
mean temperature
2–3 Water vapour in m EN 12086, method A 4.4.8
diffusion or EN ISO 15106-2 or
resistance (SD) EN ISO 15106-3, at
23 °C and 0 % to
50 % rel. humidity
2–4 Resistance to Product (underlay plus floor EN 13329 4.4.9
impact by large covering system)
diameter ball
(RLB)
2–5 Emission of Has not to be declared if EN 16516 4.4.10
formaldehyde formaldehyde has not been used
in the manufacturing process of
the floor covering or in any of the
raw materials, and if it is known
that it is not present at any stage
of the production process
2–6 Emission of VOCs  EN 16516 4.4.11
2–7 Area weight (AW)  A.3.10 4.4.12
2–8 Reaction-to-fire  EN ISO 11925-2 for 4.4.13
(RTF) classification
according to
EN 13501-1
2–9 Impact sound (IS) Weighted reduction of impact
EN ISO 10140-3 and 4.4.14
sound pressure level ΔL in dB EN ISO 717-2
w
2–10 Radiated walking in sone EN 16205:2020 4.4.15
sound (RWS)
4.4 Testing
4.4.1 General
The tests specified in this clause are based on existing standards used for other building applications and
adapted to the specific application conditions of laminate flooring underlays where needed. As result the
mean value of the measured single test results shall be calculated.
4.4.2 Thickness (t)
Thickness is the main property of an underlay to ensure functionality, such as acoustic performance or
conformability.
The thickness (t) shall be determined according to EN ISO 29466 plus the details given in A.3.1 under a
measurement load of 100 Pa (= typical load of a MMF).
4.4.3 Punctual conformability (PC)
Punctual conformability is the ability of the underlay to smoothen small local defects of the subfloor (e.g.
small protruding particles) and/or small particles laying on the subfloor when installed under a laminate
floor covering.
The punctual conformability of the underlay shall be determined by measuring the Shore-A-hardness
(SH) according to EN ISO 868 plus the details specified in A.3.6. The punctual conformability shall be
declared as PC-value (mm).
4.4.4 Compressive strength (CS)
To ensure the integrity of the MMF flooring system, the compressive strength at 0,5 mm deformation
shall be determined according to EN ISO 29469 plus the details specified in A.3.7 and with a pre-load of
100 Pa. The compressive strength shall be declared as CS-value (in kPa).
4.4.5 Dynamic load (DL and DL ) resistance
25 75
To ensure sufficient resistance of the underlay against long-term dynamic loads applied by, e.g. people
walking or sitting on a castor chair, the resistance to dynamic load shall be determined according to
EN 13793 plus the details specified in A.3.9.
The dynamic load resistance shall be declared as DL - or DL -value (number of cycles). The value is
25 75
determined as the maximum number of load cycles which can be applied to the underlay that results in a
loss in thickness of ≤ 0,5 mm.
Due to the different load distribution of different flooring types the sinusoidal loads for σ are adapted
max
to 25 kPa for floor coverings with wood based core and 75 kPa for floor coverings with non wood-based
core. Other sinusoidal loads for σ may be agreed but shall be reported. In this case the index in the
max
report shall be changed (e.g. in case of σ = 50kPa the result shall be expressed as DL ).
max 50
NOTE If DL 75 is reached also the requirements of DL 25 is fulfilled.
4.4.6 Compressive Creep (CC) resistance
To ensure sufficient resistance of the underlay against static load applied by, e.g. furniture feet, the
resistance to compressive load shall be determined according to EN ISO 16534 plus the details specified
in A.3.8 and with a pre-load of 100 Pa.
Compressive creep resistance shall be determined as the maximum applicable load in kPa resulting in a
thickness loss X = X + X of ≤ 0,5 mm after extrapolation to 10 years. The compressive creep resistance
t 0 ct
shall be declared as CC-value in kPa.
When CC is determined at temperatures other than the standard conditions as specified under A.2, the
conditions shall be reported (e.g. CC (35 °C)).
4.4.7 Thermal resistance (R)
If the MMF floor coverings is going to be installed over underfloor heating according to EN 1264-3 the
thermal resistance (R) of the f
...