Overview
ISO 7728:2026 establishes standardized requirements for typical horizontal joints formed between external walls made of prefabricated ordinary concrete components and concrete floors. The standard focuses on specifying the properties, characteristics, and classification criteria for these joints in both public and private buildings, including dwellings, offices, schools, and hospitals. It provides guidance on non-structural performance aspects of joints, such as thermal insulation, acoustics, weatherproofing, fire resistance, appearance, and durability, but explicitly excludes characteristics related to the load-bearing capacity or structural behavior of the building.
By clarifying design conventions and minimum performance requirements, ISO 7728:2026 supports professionals in the construction industry, including architects, engineers, and building product manufacturers, aiming to optimize building performance and durability.
Key Topics
- Thermal Performance: Requirements for limiting heat transfer through joints to reduce energy losses and prevent condensation. Surface temperature factors and thermal heterogeneity coefficients are addressed for maintaining internal comfort and avoiding thermal bridging.
- Acoustical Insulation: Specifies acoustic insulation metrics (such as R values) to minimize sound transmission between spaces separated by a concrete floor, following international standards for measurement and performance.
- Air and Water Tightness: Outlines methods for ensuring joints are resistant to air infiltration and water penetration, critical for energy efficiency, durability, and the prevention of water ingress.
- Fire Resistance: Sets out criteria for joint materials and construction to prevent the passage of flames, smoke, and toxic gases, ensuring safety in fire scenarios.
- Durability and Maintenance: Stipulates that jointing materials should match the expected service life of panels, with provisions for regular inspection, maintenance, and possible replacement of degradable elements.
- Appearance and Compatibility: Recommends measures to preserve internal and external aesthetics and to account for dimensional tolerances, ensuring joints accommodate movements or changes due to environmental factors.
Applications
The standardized approach provided by ISO 7728:2026 is applicable across a wide range of building types and sectors:
- Public and Private Buildings: Suitable for residential, commercial, educational, and healthcare projects using prefabricated concrete construction techniques.
- Prefabricated Building Systems: Streamlines the integration of prefabricated wall panels and floors by offering clear joint performance requirements.
- Energy-Efficient and Sustainable Design: Supports better building envelope performance, contributing to lower utility costs and improved occupant comfort by addressing air permeability, water tightness, and thermal bridging.
- Fire Safety Upgrades: Offers practical criteria for upgrading joint fire resistance in new builds or refurbishments.
- Building Maintenance and Lifecycle Planning: Guides planning for inspections, maintenance, and replacement cycles of jointing materials to ensure long-term building envelope integrity.
Related Standards
ISO 7728:2026 references and complements several other international standards in building construction:
- ISO 6589 - Laboratory test methods for assessing air permeability of joints.
- ISO 717-1 & ISO 16283-1 - Rating and field measurement of sound insulation in buildings.
- ISO 13788 - Methods for assessing risk of surface condensation.
- ISO 10211 - Detailed calculation of heat flows and surface temperatures in building components.
- ISO 9972 - Determination of air permeability of buildings by fan pressurization.
- ISO 2445, ISO 3447, ISO 6511 - General principles and modular coordination for joints in building.
For vertical joints in concrete wall assemblies, ISO 7729 provides corresponding requirements. Adhering to ISO 7728:2026 alongside these supporting standards facilitates harmonized and high-performance prefabricated concrete building envelopes.
Open preview (PDF)Typical horizontal joints between an external wall of prefabricated ordinary concrete components and a concrete floor — Properties, characteristics and classification criteria