moistureimpermeable

Moistureimpermeable is an adjective used to describe materials, finishes, or barriers that resist the transfer of moisture, including liquid water and water vapor. In practice, moistureimpermeable products are designed to prevent moisture from penetrating a structure, fabric, or package, thereby protecting contents or surfaces from dampness, corrosion, or mold growth. The term is often encountered in combination with other descriptors (for example, moisture-impermeable membranes, coatings, or barriers) and is sometimes written as moisture-impermeable or moisture impermeable.

In construction and building science, moistureimpermeable layers serve as moisture barriers or vapor barriers within wall, roof, or floor assemblies. They are used to reduce inward moisture migration from exterior to interior spaces and to manage condensation risks. However, true impermeability can conflict with breathability, so engineers balance moistureimpermeable properties with controlled drying to prevent trapped moisture. In practice, these materials may be rated by permeance or permeability rather than being completely impermeable, with lower ratings indicating greater resistance to moisture transfer.

In textiles and apparel, moistureimpermeable fabrics block water or moisture from passing through the material, providing protection in rainwear or protective gear. In packaging and electronics, moistureimpermeable films and coatings protect contents from humidity, corrosion, or degradation during storage and use.

Testing for moistureimpermeability often involves measuring water vapor transmission rate (WVTR) or specific water permeability under standardized conditions. Materials marketed as moistureimpermeable are typically evaluated for performance under relevant exposure scenarios, such as humidity, rain exposure, or immersion, to ensure suitability for their intended application.

See also: moisture barrier, vapor barrier, waterproofing, impermeable coating, WVTR.