Please login with your username and password.


Can’t remember your accounts password?

Can't access your account?

Select your language.

This page is available in the following languages:

    Please select your location

    ​​​​MasterSeal NP 1

    Elastomeric, polyurethane sealant for interior and exterior use​​

    By activating embedded YouTube videos, your personal data could be transmitted to the provider. Further information can be found in our privacy notice.

    How does MasterSeal NP 1 work?

    MasterSeal NP 1 (formerly known as Sonolastic 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. Used as an acoustic sealant, MasterSeal NP 1 reduces sound transmission in partition systems to support high STC values by sealing spaces around cut-outs and at perimeters of partitions.

    Recommended uses:

    • 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

    What are the unique features of MasterSeal NP 1?

    • Available in ProPaks, reducing jobsite waste, lowering disposal costs
    • 12 standard colors to match a wide variety of common substrates
    • Wide temperature application range makes MasterSeal NP 1 suitable for all climates
    • 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

    What are the benefits of MasterSeal NP 1?

    • 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
    • No primer required for most construction materials lowering installation costs
    • Weather resistant for long-lasting weather tight seals
    • Compatible with non-rigid coatings and can be painted
    • Superior holding power for long-lasting roof tile installation

    Direct contact

    Master Builders Solutions Technical Support

    Construction Systems


    Safety Data Sheet (SDS)

    Find all available safety data sheets for this product.

    Product Certifications

    Generate a free certificate of conformance for a specific Master Builders Solutions construction product.

    Related Literature

    Certification Letter

    pdf (120.06 Kb)

    Color Reference

    pdf (254.33 Kb)

    Data Guide

    pdf (196.54 Kb)

    LEED v4 Letter

    pdf (312.37 Kb)

    MasterSeal NP 1 Brochure

    pdf (678.62 Kb)

    MasterSeal NP 1 Guide Spec

    doc (134.00 Kb)

    MasterSeal Single Component Color Reference

    pdf (478.17 Kb)

    Roofing Applications: Sealants and Adhesives Solutions Brochure

    pdf (3.61 Mb)