Dimensional Stability of Resilient Floor Coverings according to EN ISO 23999

EN ISO 23999: Resilient Floor Coverings – Determination of Dimensional Stability and Curling After Exposure to Heat

EN ISO 23999 specifies a method for determining the dimensional stability and curling behavior of resilient floor coverings (like vinyl, linoleum, rubber, etc.) after exposure to heat. The goal is to assess how much the material changes in size and shape when subjected to elevated temperatures—an important factor for ensuring long-term performance after installation.

This test ensures that resilient floor coverings remain dimensionally stable and do not curl excessively when subjected to heat. These properties are vital for ensuring proper installation, appearance, and durability over time.

1. Sample Preparation:
   • Cut test specimens (typically square or rectangular) from the flooring material according to the standard’s dimensions, ensuring they represent the full product structure.
   • The test is performed on both unbonded (loose-laid) and, where required, bonded specimens.
2. Initial Conditioning:
   • Specimens are conditioned in a standard atmosphere (23°C ± 2°C and 50% ± 5% RH) for at least 24 hours.
   • Initial measurements of length, width, and flatness (curling) are taken with precise measuring tools.
3. Heat Exposure:
   • The specimens are then placed in an oven at 80°C ± 2°C for a specified duration (usually 6 hours).
   • During heating, the flooring is placed on a flat surface without restraint.
4. Post-Exposure Conditioning:
   • After heat treatment, specimens are cooled and reconditioned in standard conditions for at least 24 hours.
5. Final Measurements:
   • Dimensional changes (in length and width) are calculated by comparing measurements taken before and after heat exposure.
   • Curling is measured as the maximum vertical lift (edge or corner curl) from the flat surface.

• Dimensional stability is reported as a percentage change in size.
• Curling is reported in millimeters.
• The test results help determine if the product is suitable for environments with thermal variations and whether it will lay flat after installation.