Overview
EN ISO 23999:2025 (ISO 23999:2025) defines standardized methods to determine dimensional stability and curling (vertical deformation) of resilient floor coverings after exposure to heat or following reconditioning. It applies to all product forms - sheets, tiles, panels, planks and rolls - and is the fourth edition, superseding EN ISO 23999:2021. The standard was prepared by ISO/TC 219 in cooperation with CEN/TC 134 and includes test principles, apparatus, specimen preparation, measurement procedures and result expression.
Key topics and requirements
- Scope and terms: clear definitions for dimensional stability, curling, concave/convex deformation, machine direction (MD) and across machine direction (AMD).
- Test principle: measure initial dimensions and vertical deformation, expose specimens to heat (and optionally recondition), then perform final measurements to quantify linear change and curling.
- Apparatus and measuring devices: specifies typical equipment such as ovens, support plates and measurement tools - e.g. scoring devices, rigid steel plates and the block and dial gauge apparatus for tiles and planks - to ensure reproducible results.
- Specimen preparation: procedures for cutting and preparing specimens from sheets, rolls and rectangular elements (tiles/planks), including assignment of MD/AMD where relevant.
- Test sequence: conditioning, initial measurement (linear dimensions and curling), heat exposure, optional reconditioning, final measurement.
- Calculation and reporting: methods for calculating dimensional change and curling, with detailed calculation procedures presented in Annex B and measurement guidance in Annex A.
- Traceability and reporting: required test report contents to support quality control and conformity assessment.
Applications and users
This standard is intended for:
- Floor covering manufacturers - product design validation, production control and conformity to design claims.
- Independent test laboratories - reproducible type testing and certification.
- Specifiers, architects and flooring contractors - performance criteria for procurement and installation decisions.
- Regulators and conformity bodies - harmonized method for market surveillance and compliance checks.
- R&D teams - comparative testing of materials, surface constructions and heat-resistance behaviors.
Benefits include consistent, comparable data on dimensional stability, minimized risk of post-installation deformation, and objective criteria for product selection and specification.
Related standards
- EN ISO 23999:2025 replaces EN ISO 23999:2021.
- Prepared under ISO/TC 219 and CEN/TC 134 - consult national standards bodies for endorsed national versions and implementation dates.
Keywords: resilient floor coverings, dimensional stability, curling, vertical deformation, ISO 23999, heat exposure testing, floor covering testing, EN ISO 23999:2025.