Sound Attenuation: What it is and How it Works

Say “insulation,” and most people think of keeping heat in or out. However, another form of insulation can be just as important, especially in high-end residential builds, luxury homes, and commercial environments: sound attenuation.

At Seal Team, we specialize in building envelopes that deliver thermal and acoustic

performance. Whether you're starting from the ground up or enhancing an existing space, sound control strategies help create quieter, more private, and more comfortable

environments.

(Above) Hybrid flash & batt in the exterior walls and Rockwool Safe’n’Sound in the bedroom ceiling.

What Is Sound Attenuation?

Sound attenuation refers to the reduction of sound transmission through walls, floors, ceilings, and other structural elements. Unlike total soundproofing, which attempts to block all sound, attenuation focuses on minimizing noise using strategic insulation materials and construction methods.

When sound waves, whether airborne (like voices and music) or impact-based (like

footsteps or door slams), hit a surface, they can pass through unless there's something to

absorb or dampen them. That’s where our sound attenuation solutions come into play.

Why Is Sound Attenuation Important?

Improve Privacy: Prevent sound leakage between rooms, floors, or units, which is especially useful in bedrooms, shared walls, offices, or bathrooms.

Enhance Comfort: Quieter homes lead to better sleep, reduced stress, and improved focus for work or relaxation.

Increase Property Value: Buyers and tenants value quiet and well-insulated, sound-rated buildings, which often command higher prices or rent.

Fire and Moisture Resistance: Many acoustic insulations, such as ROCKWOOL and Thermafiber®, also offer excellent fire ratings and resist mold and moisture, which is especially important given our proximity to the coastline.

Code Compliance: Modern codes increasingly require sound-tested partitions with STC (Sound Transmission Class) ratings. Our solutions help you meet or exceed those benchmarks.

Best Sound Attenuation Insulation Materials

We use only high-performance products that offer sound dampening, fire resistance, and

thermal performance. Here’s a breakdown of what we trust most:

Open Cell Spray Foam

• Expands to fill cavities, trapping airborne sound.

• More effective than closed cell foam for acoustics, but less so than mineral wool.

• STC Rating: 37–39 (3")

ROCKWOOL Safe’n’Sound®

• Made for interior walls, ceilings, and floors.

• Fire-rated, moisture-resistant, and explicitly designed for acoustical performance and fire resistance.

• STC: Up to 45 | NRC: 1.05

ROCKWOOL Comfortbatt®

• Combines sound control with thermal efficiency (has an R-value), ideal for exterior walls.

• GREENGUARD Gold Certified for indoor air quality.

Thermafiber® Fire & Sound Guard® Plus

• Mineral wool hybrid insulation for residential and commercial use.

• Fire-safe, formaldehyde-free, and highly sustainable.

Fiberglass Sound Attenuation Batts (SAB)

• Unfaced fiberglass batts that absorb sound waves and offer resistance to heat flow.

• Can improve STC ratings by 2-11 points when compared to an empty cavity.

Hybrid flash & batt in the exterior walls and Rockwool Safe’n’Sound in the bathroom ceiling and interior walls.

Expert Installation Techniques

The right material matters, but installation separates a good result from a great one.

Here are some things to consider while planning your build:

1. Seal All Gaps

Use acoustic sealant around outlets, fixtures, joints, and penetrations. Even a tiny hole

can transmit sound.

2. Build Staggered Stud Walls

Staggering studs or using double-stud construction decouples wall surfaces to prevent

vibration transfer.

Note: Staggered studs take up more space but drastically increase performance.

3. Add Mass and Layers

Double drywall layers or use resilient channels to absorb and disperse sound energy.

4. Understand the Ratings

• STC (Sound Transmission Class): How well a material blocks airborne sound. A rating of 65+ is indicative of complete soundproofing, so with sound attenuation, this rating falls below that value.

• NRC (Noise Reduction Coefficient): How much sound a material absorbs.

Sound Attenuation Performance Chart

Material	Thickness	NRC	STC
Open Cell Spray Foam	3”	0.70	37-39
Closed Cell Spray Foam	2.75”	0.70	36
ROCKWOOL Safe’n’Sound	3”	1.05	45
Owens Corning R-11 Batts	3.5”	0.95	39

(Above) Hybrid flash & batt in the exterior walls and Rockwool Safe’n’Sound in this bedroom ceiling and interior walls.

Sound Attenuation in Action

Check out this video on Instagram from @construction2style for a look (and listen) at Rockwool sound attenuation in action.

Seal Team’s Integrated Approach

At Seal Team Insulation, we take sound seriously. We bring precision and performance to every wall, floor, and ceiling we encounter. 

Our team evaluates your space and recommends materials that match your acoustic, thermal, and safety requirements. Whether you're insulating a new home theater, office, bedroom, or multifamily unit, we provide targeted solutions for effective noise reduction.