Overview
ISO 20251:2024 specifies a laboratory water impermeability test for textile floor coverings. The standard defines a repeatable procedure to determine whether a textile floor covering allows liquid to penetrate through its use surface and backing. It applies to individual specimens and does not cover characterization of wall‑to‑wall tile installations.
Keywords: ISO 20251:2024, water impermeability test, textile floor coverings, laboratory test, backing penetration
Key topics and technical requirements
- Test principle: Pour a specified coloured liquid onto a concentrated area of the use surface and evaluate penetration after 24 hours.
- Test liquid: Methylene blue (1 g/L) or Acid Violet 7 (1 g/L).
- Apparatus: Open‑ended cylinder (funnel) 110 mm diameter, 1 000 mm high, non‑water permeable (e.g., PVC).
- Volume and height: Pour 100 mL of the coloured solution into the cylinder from a height of 1 m.
- Specimens: Three specimens selected per ISO 1957; minimum size 350 mm × 350 mm.
- Conditioning: Conduct test in the standard atmosphere for textiles as per ISO 139.
- Assessment: Place each specimen on white tissue paper, pour the solution, wait 24 h, then visually inspect the tissue for penetration. If no visible penetration, make a cross section to check dye in the secondary backing.
- Results reporting: Record per specimen whether penetration occurred, and declare the product water permeable or impermeable only if none of the specimens showed penetration. Test report must include product identification, test date, previous sample history, and any deviations.
Practical applications and users
ISO 20251:2024 is used for:
- Manufacturers for product development and quality control of carpets and textile floor coverings.
- Independent testing laboratories performing standardized permeability testing.
- Procurement and specification writers who need objective evidence of water impermeability for contracts (healthcare, hospitality, commercial interiors).
- Compliance and certification bodies assessing product claims.
This test helps inform decisions about product suitability where liquid resistance is important (e.g., spill-prone environments), but it is a laboratory method for specimen evaluation-not an on‑site installation assessment.
Related standards
- ISO 139 - standard atmospheres for conditioning and testing textiles (conditioning requirement).
- ISO 1957 - selection and cutting of specimens for tests on machine‑made textile floor coverings.
- ISO 2424 - vocabulary for textile floor coverings (terms and definitions referenced).
For implementation, consult the full ISO 20251:2024 document for exact procedural text and reporting templates.
