Overview - EN ISO 29466:2022 (Thermal insulating products - Determination of thickness)
EN ISO 29466:2022 (adopted by CEN) defines a reference method for measuring the thickness of full‑size thermal insulating products used in building applications. The standard specifies required apparatus, specimen preparation and conditioning, step‑by‑step measurement procedures, how to calculate and report results, and provides normative annexes for compressed products and examples of alternative methods. This method is the benchmark for correlating other test procedures used for quality control.
Key topics and technical requirements
- Scope: Applicable to full‑size thermal insulating products; provides the reference method (other methods may be used only if correlated to this one).
- Apparatus:
- Dial gauge mounted on a rigid frame with a maximum permissible error of 0.5 mm.
- 200 mm square pressure plate that applies a total pressure of (50 ± 1.5) Pa or (250 ± 5) Pa (including dial gauge force).
- Flat rigid base plate at least as large as the specimen.
- Specimen preparation and conditioning:
- Retain any facings/coatings.
- Store specimens at least 6 h at (23 ± 5) °C; in disputes use (23 ± 2) °C and (50 ± 5)% RH.
- For tropical conditions, use (27 ± 2) °C and (65 ± 5)% RH and record in the report.
- Annex A addresses preparation of compressed products.
- Measurement procedure:
- Place specimen on baseplate (faced side down if coated), apply pressure plate and dial gauge centrally.
- Number and positions of measurements depend on specimen length (e.g., two measurements for ≤600 mm, four for >600 mm to ≤1 500 mm, plus one for each additional 500 mm).
- Record individual readings and calculate the mean thickness, expressed in millimetres to the nearest millimetre (or higher accuracy if specified).
- Reporting: Test report must reference ISO 29466:2022 and include product ID, pre‑test history, conditioning, deviations, test conditions, pressure used, individual values and mean.
Applications - who uses this standard
- Manufacturers - product development, conformity, packaging and release testing.
- Independent testing laboratories - accredited thickness verification and certification testing.
- Quality control / QC teams - routine production checks (after establishing correlation if using alternative rapid methods).
- Specifiers, building inspectors and regulators - verifying declared thickness for thermal performance calculations and compliance.
- Standards developers - aligning product standards to a common reference thickness method.
Related standards and notes
- EN ISO 29466:2022 supersedes EN 823:2013 and was prepared by ISO/TC 163 in collaboration with CEN/TC 88.
- Annex B provides examples of alternative methods (allowed only when correlated to this reference method).
- The document notes that a formal statement of method accuracy will be included in a future revision.
Keywords: EN ISO 29466:2022, thermal insulating products, determination of thickness, insulation thickness measurement, test method, reference method, conditioning, dial gauge, pressure plate.