EN 17668:2022

Adhesives for floor coverings - Preparation of adhesive application - Test methods for the determination of corresponding humidity of mineral substrates

This document specifies test methods for assessment of the moisture activity of any kind of mineral substrate prior to the installation of levelling compounds and/or floor coverings or parquet floors bonded with adhesives. The methods are independent from mineral substrate chemical composition or materials and applicable with commercially available equipment.
This document is not applicable to loose lay installations.
The measurement of the moisture content of mineral substrates according to EN 13813 is described in EN 1264-4.

Klebstoffe für Bodenbeläge - Vorbereitung der Klebstoffanwendung - Prüfverfahren zur Bestimmung der korrespondierenden Luftfeuchte von mineralischen Untergründen

Dieses Dokument legt Prüfverfahren zur Messung der Luftfeuchte jeglicher Art von mineralischen Untergründen vor dem Auftrag von Bodenspachtelmassen und/oder Bodenbelägen oder Parkettböden, die mit Klebstoffen geklebt werden, fest. Die Verfahren sind unabhängig von der chemischen Zu-sammensetzung oder den Materialien des mineralischen Untergrunds und mit handelsüblichen Geräten anwendbar.
Dieses Dokument ist nicht anzuwenden für lose Verlegungen.
Die Messung des Feuchtegehalts von mineralischen Untergründen nach EN 13813 ist in EN 1264-4 beschrieben.

Adhésifs pour revêtements de sol - Préparation de l’application d'adhésif - Méthodes d’essai pour la détermination de la teneur en humidité relative d'équilibre dans les supports minéraux

Le présent document spécifie des méthodes d’essai pour mesurer l’humidité de tout type de support minéral avant la mise en œuvre d'enduits de sol et/ou de revêtements de sol ou de parquets collés à l’aide d’adhésifs. Les méthodes donnent des mesures indépendantes de la composition chimique du support minéral et sont applicables avec l’équipement disponible dans le commerce.
Le présent document n’est pas applicable à la pose libre.
La détermination de la teneur en eau des supports minéraux suivant l’EN 13813 est décrite dans l’EN 1264-4.

Lepila za talne obloge - Priprava za nanašanje lepila - Preskusna metoda za ugotavljanje ustrezne vlažnosti mineralnih podlag

Ta dokument določa preskusne metode za ugotavljanje pogojev vlažnosti različnih podlag pred nanosom izravnalnih mas in/ali talnih oblog ali parketov, lepljenih z lepili. Metode so neodvisne od kemične sestave podlage ali materialov in se uporabljajo z razpoložljivo opremo.
Za nekatere visoko reaktivne sestave na osnovi cementa (npr. trislojni sistemi) lahko proizvajalec priporoči določen čas, po katerem je podlaga pripravljena za prekrivanje.
Ta dokument podrobno opisuje metode in vključuje predlogo protokola za dokumentiranje izmerjenih vrednosti.

General Information

• Status: Published
• Publication Date: 06-Sep-2022
• ICS: 83.180 - Adhesives
• Technical Committee: CEN/TC 193 - Adhesives
• Drafting Committee: CEN/TC 193/WG 4 - Building adhesives
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 07-Sep-2022
• Due Date: 06-Apr-2023
• Completion Date: 07-Sep-2022
• Ref Project: SIST EN 17668:2022 - Adhesives for floor coverings - Preparation of adhesive application - Test methods for the determination of corresponding humidity of mineral substrates

Overview - EN 17668:2022 (CEN)

EN 17668:2022, published by CEN, specifies test methods to determine the corresponding relative humidity (CRH) of mineral substrates prior to application of levelling compounds, adhesives and bonded floor coverings (including parquet). The methods are material‑independent (not reliant on the chemical composition of the substrate) and are designed for use with commercially available hygrometers and field equipment. This standard is not applicable to loose‑lay installations.

Key topics and technical requirements

• Purpose: Measure the moisture activity of mineral substrates to decide readiness for adhesive application and to avoid moisture‑related failures.
• Three accepted test methods:
  • Hygrometer sample method: sealed container measurement of a sampled crushed material (sample: 100 ± 50 g; max grain size 8 mm).
  • Hygrometer box method: insulated impermeable box sealed to the floor creates an air pocket whose RH equilibrates with the substrate.
  • Hygrometer sleeve method: in‑situ borehole measurement using a sleeve and sensor at defined depth.
• Apparatus & accuracy: Field hygrometers measuring RH to ±3 % (10–90 % RH) and temperature to ±0.1 °C; lightweight sensors preferred to reduce thermal disturbance.
• Equipment examples: insulated vapour‑proof box, preformed butyl sealant tape, measurement sleeves, RH probes, drill and vacuum, calibrated balance and sampling containers.
• Pre‑conditioning and equilibrium times: turn off artificial drying (e.g., underfloor heating) before measurement. For unbonded substrates with a damp‑proof membrane (DPM) under the mineral substrate, allow ≥4 h before first reading; for bonded slabs or DPM below base slab allow ≥72 h; very thick constructions (>200 mm) may take considerably longer.
• Calibration & reporting: instruments must be calibrated and test reports should record method, equipment, sampling location, equilibrium criteria and measured CRH.

Applications and users

• Primary users: floor layers, adhesive manufacturers, flooring contractors, testing laboratories, specifiers and site quality inspectors.
• Practical uses:
  • Determine when levelling compounds and adhesives can be safely applied.
  • Prevent adhesive failure, loss of bond strength, odor and raised VOC emissions due to excess substrate moisture.
  • Provide material‑independent moisture activity data on concrete, screeds and other mineral bases.
• Benefits: Helps avoid costly rework, ensures durable bonded floor installations and supports compliance with product installation instructions.

Related standards

• EN 923:2015 - Terms and definitions (referenced)
• EN 13813 / EN 1264‑4 - methods for measuring moisture content (EN 17668 focuses on CRH measurement)

Keywords: EN 17668:2022, adhesives for floor coverings, moisture testing, corresponding relative humidity, hygrometer box method, hygrometer sleeve method, hygrometer sample method, mineral substrates.

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2022
Lepila za talne obloge - Priprava za nanašanje lepila - Preskusna metoda za
ugotavljanje ustrezne vlažnosti mineralnih podlag
Adhesives for floor coverings - Preparation of adhesive application - Test methods for the
determination of corresponding humidity of mineral substrates
Klebstoffe für Bodenbeläge - Vorbereitung der Klebstoffanwendung - Prüfverfahren zur
Bestimmung der korrespondierenden Luftfeuchte von mineralischen Untergründen
Adhésifs pour revêtements de sol - Préparation de l’application d'adhésif - Méthodes
d’essai pour la détermination de la teneur en humidité relative d'équilibre dans les
supports minéraux
Ta slovenski standard je istoveten z: EN 17668:2022
ICS:
83.180 Lepila Adhesives
97.150 Talne obloge Floor coverings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 17668
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2022
EUROPÄISCHE NORM
ICS 83.180
English Version
Adhesives for floor coverings - Preparation of adhesive
application - Test methods for the determination of
corresponding humidity of mineral substrates
Adhésifs pour revêtements de sol - Préparation de Klebstoffe für Bodenbeläge - Vorbereitung der
l'application d'adhésif - Méthodes d'essai pour la Klebstoffanwendung - Prüfverfahren zur Bestimmung
détermination de la teneur en humidité relative der korrespondierenden Luftfeuchte von
d'équilibre dans les supports minéraux mineralischen Untergründen
This European Standard was approved by CEN on 10 July 2022.

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
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17668:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Apparatus . 6
5 Test procedures . 8
5.1 Principle . 8
5.2 Preparations in general . 9
5.3 Specific preparations before measurement . 9
5.3.1 Hygrometer sample method . 9
5.3.2 Hygrometer box method . 9
5.3.3 Hygrometer sleeve method . 10
5.4 Recording measured values . 11
5.4.1 General . 11
5.4.2 Hygrometer sample method . 11
5.4.3 Hygrometer box method . 12
5.4.4 Hygrometer sleeve method . 12
6 Test report . 12
Bibliography . 14

European foreword
This document (EN 17668:2022) has been prepared by Technical Committee CEN/TC 193 “Adhesives”,
the secretariat of which is held by UNE.
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 March 2023, and conflicting national standards shall be
withdrawn at the latest by March 2023.
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.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations 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.
Introduction
This document describes test methods for measuring humidity in, at or from a mineral substrate. Using
these test methods will assist a floor layer in determining whether a floor is suitable to accept a levelling
compound and/or an adhesive and a floor covering. High humidity can lead to the decomposition of
moisture-sensitive levelling compounds and/or the decomposition or disruption and subsequent
weakening of flooring adhesives used for installation. This results in a complete failure of the construction
or in a reduction in adhesive strength and a negative impact on indoor air quality due to increased overall
VOC emissions and bad odour. Using these test methods, a floor layer will be able to decide on the time
at which the levelling compound and/or adhesive can be applied in order to help to avoid potential,
humidity related problems. They provide data to determine whether the load-bearing, mineral substrate
is ready for covering.
This document supplements the national standards already described for determining the moisture
conditions of mineral substrates.
The material independent information regarding the moisture activity is one of the advantages of these
measurement methods. They provide reliable data to help to establish the readiness for installation,
especially for mineral substrates containing additives.
SAFETY WARNING — Persons using this document should be familiar with normal practice. The
document cannot address all safety problems that can be associated with its application. It is the
responsibility of the user to define measures for health and safety at work and ensure that these
correspond with the European and national regulations.

1 Scope
This document specifies test methods to measure humidity of any kind of mineral substrate prior to the
installation of levelling compounds and/or floor coverings or parquet floors bonded with adhesives. The
methods are independent of the mineral substrate chemical composition or materials and applicable with
commercially available equipment.
This document is not applicable to loose lay installations.
The measurement of the moisture content of mineral substrates according to EN 13813 is described in
EN 1264-4.
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 923:2015, Adhesives — Terms and definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 923:2015 and the following
apply.
ISO and IEC maintain terminological 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
moisture
presence of water in trace amounts
3.2
humidity
water vapour partial pressure present in air
3.3
relative humidity
RH
ratio of the partial pressure of water vapour to the equilibrium vapour pressure of water at a given
temperature
Note 1 to entry: It is usually expressed as a percentage.
3.4
corresponding relative humidity
CRH
relative humidity in percent, which is present in the air close to a sample of the material at equilibrium
Note 1 to entry: The corresponding relative humidity is expressed in % RH or as the absolute number as water
activity.
3.5
hygrometer sample method
method to measure humidity of a mineral substrate by measuring the relative humidity in a container
(e. g. polyethylene bag or flask) directly at a sample of the mineral substrate
3.6
hygrometer box method
method to measure humidity of a mineral substrate by measuring the relative humidity in a pocket of air
entrapped between an impervious thermally insulated housing and the mineral base
3.7
hygrometer sleeve method
method to measure humidity of a mineral substrate by measuring the humidity inside predrilled
boreholes within a sleeve with an opening at defined depth
Note 1 to entry: Depth definitions are only available if concrete is the mineral substrate.
3.8
calibration
comparison of the value measured by an instrument with a well-defined reference value, traceable and
of an accuracy at least one class better than that of the measuring instrument
Note 1 to entry: A calibration covering the whole working range of the measuring instrument provides a basis for
an adjustment of the values measured by the instrument.
4 Apparatus
4.1 Hygrometer. An instrument capable of measuring the temperature and relative humidity shall be
used (see Figure 1). The instrument and sensors shall be suited for use in the field. After calibration, the
instrument shall measure relative humidity to an accuracy of ± 3 % between 10 % RH to 90 % RH and
temperature to an accuracy ± 0,1 °C.
Dimensions in millimetres
a) Typical apparatus using hygrometer

b) Typical apparatus using RH probe
Key
1 window
2 insulation
3 butyl sealant
4 vapour barrier
5 floor
6 humidity measuring tip
7 air pocket
8 RH probe
9 plug
Figure 1 — Typical apparatus for the hygrometer box method (see [3])
Light weight and small size measurement sensors are preferred to avoid measurement error related to
temperature changes during measurement. Moisture transfer through measurement sensor from the
borehole to surroundings shall be eliminated. Sensor response time shall be applicable for the purpose.
Measurement accuracy is normally lower than accuracy of sensor due to the measurement error sources
during measurement.
The instrument manufacturer should define the required values for reliable measurement.
4.2 Insulated impermeable box, which can be sealed to the floor surface to create an enclosed pocket
of air which is isolated from fluctuations in humidity and temperature from outside air (examples of
suitable equipment are shown in Figure 1).
It is essential that the insulated box is sealed to the floor using a preformed butyl seala
...