PROSOCO Cat 5 Rain Screen

FLUID-APPLIED AIR AND WATER-RESISTIVE BARRIER FOR RAIN SCREEN CONSTRUCTION

Cat 5 rain screen is a high-performance, fluid-applied membrane that delivers exceptional air and water protection behind open-jointed or vented rain screen cladding. Applied with a sprayer or roller, it forms a seamless, elastomeric barrier that resists extreme weather—including conditions equivalent to a Category 5 hurricane. Cat 5 Rain Screen is ideal for above-grade wall assemblies and performs reliably on dry or damp substrates, helping to eliminate weather-related construction delays.

KEY FEATURES

• Strong durable protection – withstands extreme weather, including 155-mph winds

• Can be sprayed or rolled – speeds up installation and ensures full coverage

• Bonds to damp substrates – installs even in wet conditions without delay

• Creates a seamless membrane – no laps, gaps, or fastener penetrations

• Self-seals around fasteners – eliminates leaks and maintains performance

• Meets highest code & air tightness standards – ABAA certified and NFPA 285 compliant

• Solvent-free – safe for indoor and outdoor applications

• Phthalate-free – healthier and more sustainable choice

• VOC-compliant – less than 30 g/L VOC content

SUSTAINABILITY & CERTIFICATIONS

• Declare Label – Red List Free

• SCS Certified

• LBC Red List Conformant

• ABAA Certified

• NFPA 285 Compliant

• Complies with ASTM E 96, E 2178, E 2357, D 1970, D 4541, E 84, D 2247, E 331, E 1233, E 72, AATCC-127, C 1305, NFPA 268

TECHNICAL DATA

• Shelf life – 1 year (unopened)

• VOC content – <30 g/L

• Form – viscous liquid, dark bronze color

• Coverage rate –
   • Exterior Gypsum, OSB, Plywood: 50–100 sq ft/gal
   • CMU: 50–80 sq ft/gal

• Flash point – >200° F (93° C)

• Total solids – 99%

• Weight per gallon – 11.3 lbs

• Available sizes – 5-gallon pail

OVERVIEW

Cat 5 Rain Screen is a silyl-terminated polymer (STP) that combines the flexibility of silicone with the strength of polyurethane. Designed for pressure-equalized rain screen systems, it offers superior adhesion, crack bridging, and long-term weather resistance. Its ability to bond to common building materials—without primer, and even in wet weather—makes it a go-to solution for contractors seeking speed, simplicity, and proven performance.

RESOURCES

• Product Data Sheet
• Product Data Sheet (Canadian French)
• Product Data Sheet (Spanish)
• Safety Data Sheet
• Safety Data Sheet (Spanish)
• SDS Canadian French
• VOC Compliance
• ABAA Certification
• Product Test Data
• ICC-ES Report
• NFPA 285 Compliant Wall Assemblies
• LEED Verification Letter
• SCS Certification
• Declare Label
• LBC Red List Conformant Product Summary