Overview
The SIST EN ISO 12572:2016/A1:2025 amendment updates the established European and International Standard for determining the hygrothermal performance of building materials and products through the water vapour transmission properties using the cup method. Approved by the European Committee for Standardization (CEN) in September 2024, this amendment refines test procedures and calculation formulas essential for accurate assessment of moisture diffusion in construction materials. The standard is vital for architects, engineers, material scientists, and quality inspectors focused on building envelope performance, moisture control, and durability.
Key Topics
- Water vapour transmission measurement: This standard specifies methods to evaluate how building materials transmit water vapour, which is critical for managing moisture and preventing damage in constructions.
- Cup method refinement: The amendment modifies the existing cup method, a widely used laboratory test involving sealed cups filled with desiccant or water to measure vapour flux.
- Water vapour resistance factor (μ): Updated calculation methods using precise formulas, including the Schirmer formula for water vapour permeability of air (δa), are introduced for better accuracy.
- Barometric pressure considerations: The amendment clarifies that μ, the water vapour resistance factor, is generally independent of barometric pressure, providing guidance on calculating δa at actual barometric conditions.
- Thermal and moisture performance: By improving test reliability, the standard supports better understanding of hygrothermal behaviors influencing insulation, condensation risks, and overall material longevity.
Applications
This standard amendment is applicable in diverse sectors related to construction and building materials, including:
- Material testing laboratories: For routine quality control and conformity assessment of building materials like insulation panels, vapour barriers, and cladding systems.
- Building design and construction: Helps architects and engineers select materials with suitable vapour transmission properties to enhance indoor air quality and structural integrity.
- Energy-efficient buildings: Essential for developing airtight yet breathable building envelopes that comply with energy-saving directives and moisture control best practices.
- Waterproofing and moisture protection: Supports evaluation of products designed to resist moisture ingress while allowing controlled vapor diffusion, preventing mold and decay.
- Research and development: Facilitates innovation in sustainable and high-performance building materials with optimal hygrothermal characteristics.
Related Standards
- ISO 12572:2016 – The base international standard for water vapour transmission using the cup method.
- EN ISO 12572:2016 – The harmonized European version of the ISO 12572 standard.
- CEN/TC 89 – Technical committee responsible for thermal performance of buildings and components.
- Other hygrothermal standards – Standards covering thermal insulation, moisture control, and durability assessment of construction products.
- ISO/IEC Directives – Guidelines governing the development and maintenance of ISO standards in the building sector.
By adhering to SIST EN ISO 12572:2016/A1:2025, stakeholders ensure precise, standardized methods for evaluating water vapour transmission properties of construction materials. This leads to enhanced building performance, longevity, and sustainability in alignment with European and international regulatory frameworks.