ICC-ES AC528
Full Name
ICC-ES AC528 – Acceptance Criteria for Humidity-dependent Vapor Retarders
Scope
ICC-ES AC528 establishes the requirements for humidity-dependent vapor retarders, which are materials used in building construction to control moisture movement within wall assemblies. These materials are designed to adapt their permeability to water vapor based on the relative humidity of the surrounding environment, allowing them to function as both vapor retarders and vapor-open membranes depending on the conditions.
The scope of AC528 includes:
- Material properties: defining the performance requirements for humidity-dependent vapor retarders, including their vapor permeability range, moisture buffering capacity, and resistance to aging and degradation.
- Testing procedures: establishing standardized test methods for evaluating the performance of these materials under varying humidity conditions and temperatures.
- Installation requirements: providing guidelines for the proper installation of humidity-dependent vapor retarders to ensure their effectiveness in controlling moisture movement within building assemblies.
The primary goal of AC528 is to ensure that these vapor retarders perform as intended and contribute to the overall durability and energy efficiency of buildings by preventing moisture-related damage and mold growth.
Resources
Keywords
humidity-dependent; vapor retarder; vapor permeability; moisture buffering; aging; degradation; installation