Cat 5 Rain Screen | Fluid-Applied Barrier for Rain Screen Construction
Cat 5 Rain Screen by PROSOCO is a durable, fluid-applied air and waterproof barrier engineered to meet the challenges of pressure-equalized rain screen cladding systems. This high-performance membrane is based on silyl-terminated polymer (STP) chemistry, delivering a seamless, elastomeric barrier that can be spray- or roller-applied onto most building surfaces, including OSB, plywood, CMU, and gypsum board.
Product Description
Designed to withstand extreme weather conditions, Cat 5 Rain Screen forms a waterproof membrane that eliminates air leaks, resists wind-driven rain, and bridges cracks and joints for a continuous seal. It meets stringent code compliance requirements and can be applied in wet conditions without primers. The formulation is solvent-free, isocyanate-free, and phthalate-free—safe for job sites and compliant with VOC regulations.
Key Benefits of Cat 5 Rain Screen
- Optimized for open-jointed or vented rain screen cladding
- Sprayable for faster and easier installation
- Forms a tough, seamless barrier that withstands Category 5 hurricane conditions
- Compatible with most paints, adhesives, and waterproofing membranes
- VOC content <30 g/L and meets all U.S. regulatory requirements
Common Applications
- Exterior gypsum board and plywood wall systems
- OSB sheathing in ventilated rain screen facades
- Concrete masonry units (CMU) and precast walls
- Above-grade vertical wall assemblies in open-joint designs
Storage & Packaging
Cat 5 Rain Screen is packaged in 5-gallon pails with a 1-year shelf life when stored in tightly sealed containers. The dark bronze viscous liquid has a mild odor and can be applied to dry or damp substrates without priming.
Product Properties
| Property | Value |
|---|---|
| Shelf Life | 1 year in a tightly sealed, unopened container |
| VOC Content | <30 g/L |
| Form | Viscous liquid, mild odor, dark bronze color |
| pH | Not applicable |
| Coverage Rate | 50–100 sq ft per gallon on gypsum, OSB, or plywood; CMU: 50–80 sq ft per gallon |
| Freeze Point | Not applicable |
| Flash Point | >200°F (>93°C) |
| Total Solids | 99% |
| WT/GAL | 11.3 lbs |
| Available Sizes | 5-gallon |
For ICF-specific wall assemblies, check out the high-performance Cat 5 ICF. For more detailed documentation and support, visit the official PROSOCO site.
