Sto Flexyl®

Sto Flexyl® — Flexible Waterproofing & Adhesive for EIFS and Foundations
Sto Flexyl® is a high-performance, acrylic-modified material that functions as both a base coat adhesive and a waterproofing agent. Ideal for use with StoTherm® ci Systems and masonry substrates, it combines fiber-reinforced strength with flexibility for durable performance across a wide range of environmental conditions.

Looking for a waterproofing solution that’s easy to use and built to last? Sto Flexyl® delivers on-site efficiency, long-term resilience, and peace of mind—whether you’re detailing a façade or protecting below-grade foundations.

• Dual-purpose use as base coat adhesive or below-grade waterproofer
• Remains flexible in extreme conditions from -37ºC to 30°C (-36ºF to 86°F)
• Withstands 60 freeze/thaw cycles without degradation
• Water-based and solvent-free for low environmental impact and easy cleanup
• Compatible with concrete, masonry, plaster, gypsum, and cement sheathing

System Composition & Coverage

• As Adhesive: 80–110 ft² (7.4–10.2 m²) per pail when mixed with Portland cement
• As Base Coat or Waterproofer: 150–180 ft² (13.9–16.7 m²) per pail
  Note: Coverage may vary based on surface texture, porosity, and application method.

Product Bulletin

Safety Data Sheet