MasterSeal NP 1 is a one-component, high-performance, non-priming, gun-grade, elastomeric 
polyurethane sealant. It requires no mixing and typically requires no priming to bond to many 
materials, including concrete and masonry.


  • Interior and exterior

  • Above and below grade 

  • Immersed in water

  • Expansion joints

  • Panel walls

  • Precast units

  • Aluminum and wood window frames

  • Roofing

  • Fascia

  • Parapets

  • Vinyl siding

  • Store front assemblies

Product Highlights

  • One-component formula requires no mixing, helping to reduce labor costs

  • Joint movement capability ±35% provides excellent flexibility for keeping moving joints weathertight

  • Easy to gun and tool, speeding up application and making neater joints

  • Available in ProPaks, reducing jobsite waste, lowering disposal costs

  • 12 standard colors to match a wide variety of common substrates

  • No primer required for most construction materials lowering installation costs

  • Weather resistant for long-lasting weathertight seals

  • Wide temperature application range makes masterSeal nP 1 suitable for all climates

  • Compatible with non-rigid coatings and can be painted

  • Superior holding power for long-lasting roof / tile installation

  • Ul listed; Passes 4–hour, 4–inch, fire and hose stream test when used with Ultra Block or mineral wool

  • Suitable for water immersion with documented performance in wet areas

  • Meets Voc requirements in all 50 states