Overview
ISO 10545-2:2018 - "Ceramic tiles - Part 2: Determination of dimensions and surface quality" defines standardized test methods for measuring the dimensional characteristics and surface quality of ceramic tiles. The standard specifies how to measure length, width, thickness, straightness of sides, rectangularity, surface flatness (curvature and warpage) and how to assess surface defects. Tiles smaller than 4 cm² are excluded from most dimensional measurements. The document also clarifies which edge irregularities (e.g., spacer lugs, glaze blobs) can be ignored when they will be hidden by joints after installation.
Key topics and technical requirements
- Scope and exclusions: Methods apply to ceramic tiles except those with area < 4 cm² for many dimensional tests.
- Measurement parameters: length, width, thickness, straightness of sides, rectangularity, centre/edge curvature, warpage and surface flatness are defined and measured.
- Apparatus examples: Vernier calipers or other linear measuring devices for length/width; micrometer screw gauge (anvils 5–10 mm) for thickness; specified fixtures and measuring aids for straightness, flatness and curvature.
- Sampling: Sample sizes vary by tile area (e.g., 10 tiles when A ≤ 0.04 m²; 7 tiles when 0.04 m² < A ≤ 0.36 m²; 5 tiles when A > 0.36 m²).
- Measurement procedures:
- Length/width: measurements taken to the nearest 0.1 mm, typically 5 mm from the corners.
- Thickness: measured on diagonals in four segments at the thickest point; include ribs/back-feet.
- Surface flatness: measurements in three positions across the tile; tiles with relief may be measured on the back.
- Expression of results: Deviations are reported both in millimetres and as percentages (a key revision in the 2018 edition).
- Surface quality definitions: standardized terms and defects - crack, crazing, dry spot, pin hole, speck, blister, chip, rough edge, welt, polishing defects, etc.
- Test reporting: Required report items include reference to ISO 10545-2, tile description, all individual measurements, averages and deviations (both % and mm).
Applications and users
ISO 10545-2 is used for:
- Quality control in tile manufacturing and glazing processes
- Incoming goods inspection by distributors and retailers
- Laboratory testing and conformity assessment by testing bodies
- Specification and procurement by architects, specifiers and contractors
- Regulatory compliance and product certification
Using this standard helps ensure consistent, reproducible measurements for dimensional tolerancing and surface acceptability, improving installation outcomes and reducing nonconformity disputes.
Related standards
- Part of the ISO 10545 series (other parts cover physical and chemical tests for ceramic tiles). Users should consult the full ISO 10545 series for complementary test methods and performance requirements.
