Product Data Sheet

Sikaflex®-1A is a high-performance, one-component polyurethane sealant and adhesive engineered for flexible joint sealing and bonding in demanding construction and industrial environments. Its moisture-curing, non-sag formulation creates durable elastomeric seals that maintain long-term flexibility, adhesion, and weather resistance in both interior and exterior applications.

Designed for vertical and horizontal joints, Sikaflex®-1A bonds effectively to a wide range of common building materials including concrete, masonry, metal, glass, aluminum, wood, and many coated surfaces. Its exceptional elasticity allows it to accommodate joint movement up to ±35%, helping absorb expansion, contraction, vibration, and thermal movement without cracking or losing adhesion.

Sikaflex®-1A is commonly used for sealing windows, door frames, flashing, expansion joints, roofing details, reglets, pipe penetrations, and construction joints where long-lasting waterproofing and flexibility are essential. The sealant can also be used as an elastic adhesive between materials with different expansion rates, supporting reliable performance across a variety of construction assemblies.

Its durable polyurethane formulation offers excellent resistance to aging, weathering, water, fuel, and many environmental conditions. Sikaflex®-1A can be applied to green and damp concrete, making it especially useful for fast-paced construction schedules and challenging jobsite conditions. Once cured, the material forms a tough, tear-resistant seal that remains flexible over time.

The product is easy to apply using standard caulking equipment and requires little to no mixing or special preparation. Certified to ASTM C920 and NSF/ANSI/CAN 61 standards, Sikaflex®-1A is suitable for a wide range of professional sealing and waterproofing applications, including projects involving potable water exposure.

Key Features

• One-component polyurethane sealant and adhesive
• Flexible elastomeric sealing performance
• Accommodates joint movement up to ±35%
• Excellent adhesion to concrete, metal, glass, masonry, and wood
• Non-sag formula for vertical and horizontal applications
• Resistant to weathering, water, aging, and fuel exposure
• Can be applied to green and damp concrete
• Tough, tear-resistant, and permanently flexible
• Paintable after curing
• Certified to ASTM C920 and NSF/ANSI/CAN 61 standards