Overview
ISO/TS 11665-13:2025 - Measurement of radioactivity in the environment - Air: radon 222 - Part 13 defines a membrane two‑side activity concentration test method to determine the radon diffusion coefficient in waterproofing materials (bitumen or polymeric membranes, coatings, paints). The Technical Specification sets out test principles, measuring‑system configurations, sample preparation, test procedures, and result expression. Porous materials are explicitly excluded, since radon transport in those materials depends on porosity and moisture.
Key topics and technical requirements
- Scope and applicability: laboratory assessment of radon diffusion through non‑porous waterproofing materials used as radon‑proof insulation.
- Measuring system: required components and alternative configurations for radon sources and detectors; procedures to ensure radon‑tight mounting and to assess leakage of receiver containers.
- Test methods: four methods are specified for different experimental conditions:
- Method A - non‑stationary radon diffusion (transient phase).
- Method B - stationary radon diffusion (steady‑state).
- Method C - steady state established during ventilation of the receiver container.
- Method D - stationary conditions using activity concentrations in both source and receiver containers (new in 2025 edition).
- General procedures: sample preparation, fixing samples in the test rig, minimum measurement durations, and procedures when growth curves are unclear or no radon is detected in the receiver.
- Uncertainty and detection: guidance on expressing results, reporting relative uncertainty, decision thresholds, detection limits and confidence intervals.
- Quality and calibration: requirements for quality management, calibration of devices, and comprehensive test reporting (includes required metadata and test conditions).
Applications and users
This standard is intended for:
- Materials manufacturers developing or certifying radon‑resistant membranes, coatings and paints.
- Accredited testing laboratories performing radon diffusion coefficient measurements for compliance and product labelling.
- Building engineers, architects and regulatory bodies specifying radon‑proof materials in building codes or mitigation strategies.
- Radon mitigation professionals selecting barrier materials in combination with ventilation or sub‑slab systems.
- Research groups studying radon transport in construction materials (non‑porous).
Practical applications include product qualification for radon‑proof insulation, support for building code requirements, and comparative evaluation of membrane performance.
Related standards
Keywords: ISO/TS 11665-13:2025, radon diffusion coefficient, membrane two‑side activity concentration test, radon measurement, waterproof materials, radon‑proof insulation, radon testing method.