ISO 25014:2026

ISO 25014:2026 is an ISO International Standard for determining the film thickness of a coating on a concrete substrate by a cross-section method. It is intended for measuring cured coating build-ups, especially in flooring systems, and it combines sample preparation, microscopic measurement and reporting rules.

What does ISO 25014:2026 specify?

ISO 25014:2026 specifies methods for determining the film thickness of a coating on concrete substrate by cross-section method. In practice, it tells the user how to take a concrete core, prepare a cross-section, measure the coating layers and report the results.

The document is organized into:

• Scope
• Normative references
• Terms and definitions
• Principle
• Apparatus
• Test specimen
• Procedure
• Precision
• Test report

What are the key requirements of ISO 25014:2026?

ISO 25014:2026 focuses on how to prepare a coated concrete sample so that the coating layers can be measured reliably under a microscope. The main practical point is that the thickness is not measured on the surface, but on a prepared cross-section.

Sampling and specimen preparation

The document calls for drill cores from coated concrete structures, taken perpendicular to the surface and in a way that avoids damage. If reinforcement is encountered, drilling is stopped and the core is removed. The core is marked, its location and direction are recorded, and it is cut open centrally and perpendicular to its surface.

For the specimen size, drill cores with a diameter of 5 cm and a maximum depth of 2 cm are described as sufficient for film thickness measurement. The cores are then separated, embedded, ground and polished so that the individual layers can be clearly distinguished optically.

Measurement setup

ISO 25014:2026 uses a cross-section machine, embedding moulds, grinding and polishing equipment, and an optical microscope with thickness measuring software. The practical meaning is that the method depends on sample preparation quality as much as on the microscope itself: poor cutting, embedding or polishing can blur layer boundaries and affect the reading.

The document also recommends photographic documentation of the whole cross-section. The image resolution should be fine enough that the pixel size is at least 10 times smaller than the thickness being measured, so the layer edges can be identified with usable precision.

Method A and Method B

ISO 25014:2026 provides two ways to evaluate thickness.

• Method A: Minimum/maximum method - additional images are taken at three spots, two minimum and two maximum values are determined for each layer, and the average is calculated from 12 individual measurements. The minimum and maximum thicknesses are also reported. This is useful when a layer shows visible variation and the reader needs both average and spread.
• Method B: Average method - thickness is measured over a defined 5 cm distance with equidistant points. At least 10 measurements are required, and up to 100 are recommended for automated image analysis. This suits users who want a more direct average over a longer section.

For multilayer structures, both methods are applied to each layer, and the total film thickness may also be determined.

Number of specimens, precision and reporting

The number of drill cores is agreed between the interested parties, so the sampling plan is not fixed by the standard. The precision clause states that precision data are currently not available, which matters when comparing results between laboratories or contracts.

The test report must identify the specimen, cite ISO 25014:2026, state the method used, identify the microscope and software, and give the results. It also records deviations from the method, unusual features observed during testing, and the test date.

What terms does ISO 25014:2026 define?

ISO 25014:2026 uses the terms and definitions from ISO 4618. Key terms used in this document include:

• Film thickness - the thickness of the coating layer measured on the prepared cross-section.
• Coating - the material layer applied to the concrete substrate and examined in cross section.
• Concrete substrate - the concrete base that carries the coating.
• Drill core - the cylindrical sample removed from the coated concrete for examination.
• Cross-section - the cut face prepared through the sample so the layers can be seen and measured.
• Embedding - enclosing the cut specimen in a solid medium, typically epoxy resin, to support grinding and polishing.
• Optical microscope - the instrument used, with thickness measuring software, to read layer thicknesses.

Who uses ISO 25014:2026?

ISO 25014:2026 is used by laboratories, coating manufacturers, flooring applicators, and technical staff who evaluate coated concrete systems. The introduction links it to product development, application assessment, and the evaluation of claims.

It is especially relevant for cured flooring system build-ups, where quartz sand-filled systems can be difficult to measure by other means. Quality managers and buyers may use it to agree how coating thickness will be checked and reported.

Which standards are used with ISO 25014:2026?

• ISO 4618, Paints and varnishes - Vocabulary - provides the terms and definitions used in ISO 25014:2026.

What does the ISO 25014:2026 document contain?

ISO 25014:2026 contains the apparatus needed for cross-section preparation, including the cross-section machine, embedding moulds, grinding and polishing equipment, and an optical microscope with software. It also includes specimen preparation guidance for drilling, marking, embedding, grinding and polishing.

The procedure section presents two measurement approaches, Method A and Method B, and explains how many readings to take and how to treat multilayer structures. The document also gives a reporting list for test results and observations, and a precision clause stating that precision data are currently not available.

The contents also include practical guidance on image documentation and measurement point spacing, which helps laboratories set up a repeatable workflow for thickness measurement on coated concrete.