Sikaflex NP 1 – Gun-Grade, One-Component Polyurethane Joint Sealant (Formerly MasterSeal NP 1)

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Sikaflex NP 1 (formerly MasterSeal NP 1) is a one-component, gun-grade, elastomeric polyurethane sealant designed to deliver durable, weather-tight, and sound-damping performance in a wide range of construction and expansion-joint applications. Easy to gun and tool, Sikaflex NP 1 requires no mixing and is available in multiple standard colors to match common substrates.

This sealant provides excellent flexibility, adhesion, and weather resistance, making it suitable for both interior and exterior use, including above- and below-grade joints. It is effective for expansion joints, precast and tilt-up panel joints, window and door frames, roofing, storefront assemblies, and more. Because it cures to a tough, flexible rubber, Sikaflex NP 1 also excels as an acoustical sealant — reducing sound transmission when used in partition systems, cut-outs, or around penetrations.

Benefits

• One-component, moisture-curing polyurethane sealant — no mixing needed
• Gun-grade non-sag formulation for neat, professional joints
• ±35% movement capability — ideal for expansion and structural joint applications
• Non-priming on many substrates (verify per project) — reduces prep time
• Available in 12 standard colors to match architectural finishes
• Weather-, water- and UV-resistant for long-term exterior durability
• Can be painted or coated to match wall or substrate finishes

Typical Applications

• Expansion and control joints in concrete and masonry
• Precast and tilt-up panel joints
• Panel walls, curtain walls, storefront assemblies
• Aluminum and wood window & door frames
• Roofing, fascia, parapets, exterior transitions
• Interior partition sealant and sound-damping joints
• Joints exposed to moisture or water – with correct priming where required