Description

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Thermafiber® RainBarrier® Mineral Wool Insulation is a high-performance continuous insulation solution engineered for rainscreen and cavity wall systems. Designed to provide thermal control, fire resistance, vapor permeability, and water drainage within exterior wall assemblies, RainBarrier® supports durable, energy-efficient building envelope design.

This non-combustible mineral wool insulation meets ASTM C612 standards and offers flame spread and smoke developed ratings of 0 when tested to ASTM E84. With an R-value of approximately 4.3 per inch and nominal density of 6.0 pcf, RainBarrier® enhances energy efficiency while contributing to fire-resistive wall assemblies. It is mold-resistant, non-deteriorating, inorganic, and compatible with common wall ties, air barrier systems, and adhesives.

RainBarrier® also delivers strong acoustical performance, making it ideal for commercial buildings where sound attenuation is critical. Its semi-rigid structure repels and drains water while maintaining vapor permeance (25–50 perms), allowing wall systems to dry effectively. Available in thicknesses from 1″ to 8″ and optional black veil facing for open-joint façade applications, Thermafiber® RainBarrier® is a versatile solution for modern exterior wall construction.