SpecSeal® Smoke ’N’ Sound Acoustical Spray

Now Enhanced for High-Build Performance

At Hewson Brothers, we work closely with contractors across commercial and institutional projects, and one thing is consistent: installation efficiency matters just as much as performance. That’s why we’re proud to feature the enhanced SpecSeal® Smoke ’N’ Sound (SNS) Acoustical Spray from STI, now reformulated for thicker, more controlled applications.

Contractors told STI they wanted to spray SNS thicker without sagging, running, or fighting the material. The result is a smarter formulation with increased viscosity and improved rheology, designed to deliver better hang, smoother build, and less rework on site.

Designed for Thicker Application

SNS Spray was originally optimized for approximately 1/8″ (3.2 mm) wet thickness, a common benchmark in acoustical joint sealing. The enhanced formula now supports application from 1/8″ up to approximately 5/16″ wet thickness, depending on substrate and conditions.

For contractors, that means:

  • Fewer passes to achieve required coverage
  • Better performance on vertical and overhead surfaces
  • Greater control in demanding jobsite conditions

As STI describes it, the product is “Enhanced for more control. Engineered for high-build performance.”

Beyond improved application performance, SNS Spray continues to deliver the smoke and acoustical control contractors rely on. This water-based acrylic latex spray is designed to seal gaps, linear joints, and penetrations in non-fire-rated wall, floor, and ceiling assemblies.

When properly installed, it forms a flexible, durable seal that limits the passage of smoke, airborne particulates, and sound. It has been acoustically tested in accordance with ASTM E90 and demonstrates air leakage performance of less than 1 CFM in modified UL testing, while accommodating normal building movement with ±12.5% joint movement capability.

SpecSeal® Smoke ’N’ Sound Acoustical Spray was the first smoke and acoustical spray of its kind, and this enhanced formulation builds on that legacy by aligning even more closely with how contractors actually work — thicker, faster, and with greater control. At Hewson Brothers, we’re pleased to supply solutions that make installation easier without compromising performance. For more information on availability or application support, connect with your Hewson Brothers representative.