City sirens, lawnmowers, upstairs footsteps noise seeps in through the same gaps that let in drafts. The upside is that many of the same fixes that improve comfort also soften unwanted sounds. With the right insulation in the right places, your home can feel calmer and more private.

If you’d like tailored advice, our team is available to walk you through options. Start with our insulation services or connect through our contact page.

Understanding STC, NRC, and R-Value

Sound Transmission Class (STC) measures how well a wall, floor, or ceiling blocks airborne noise like voices or music. The higher the number, the less you hear. Noise Reduction Coefficient (NRC) is different it shows how much sound a material absorbs inside a room to cut down echo.

R-value is often mistaken for an acoustic rating, but it only measures thermal resistance. While extra insulation can help absorb sound indirectly, a high R-value doesn’t guarantee quiet. That’s why the right product and installation matter.

Which Insulation Works Best for Sound?

Mineral wool batts are dense and springy, making them excellent at absorbing mid-to-high frequencies while adding mass to walls and floors. Fiberglass batts, more budget friendly, also perform well when cavities are completely filled without gaps.

Blown-in cellulose is effective in older homes or irregular spaces. It reduces sound by filling small voids where air and noise slip through, while also boosting thermal comfort.

Rigid underfloor foam helps reduce impact noise such as footsteps, especially when paired with quality flooring underlayment. Spray foam, on the other hand, is best treated as an air-sealing tool; it’s not a top performer acoustically without additional layers like mineral wool or double drywall.

Where to Focus Insulation for Noise Control

For bedrooms or home offices, filling stud bays with mineral wool or fiberglass helps reduce airborne noise. Adding resilient channels or a second layer of drywall with damping compound further increases performance.

Between floors, use mineral wool in joist cavities for airborne sound, then combine with a proper underlayment on the floor above to cut impact noise.

In attics, continuous blown-in cellulose or fiberglass helps reduce outside noise from traffic or aircraft. Always air seal lighting cans, chases, and gaps first so sound doesn’t sneak through.

Mechanical systems deserve attention too. Wrapping ducts, isolating bath fans, and sealing joist chases with mineral wool can stop small but disruptive noise pathways.

Thickness, Density, and What They Mean

The goal is to fill cavities completely. A standard 2x4 wall with 3½-inch batts achieves a mid-30s STC, while switching to mineral wool and adding resilient channels or extra drywall can raise performance above STC 50, often the target in multifamily construction.

Density plays a role, but balance is key. Fibrous and mineral materials absorb sound, while added mass and decoupling break vibration paths. NRC ratings help evaluate how a room will “feel,” while STC tells you how much noise will pass through the structure.

Small Additions That Make a Big Difference

Sealing gaps at baseboards, outlets, and attic hatches cuts both drafts and flanking noise. Upgrading windows to laminated glass and swapping hollow interior doors for solid-core ones adds noticeable quiet.

Wrapping ducts, isolating pipe hangers, and adding soft finishes like rugs, drapes, and upholstered furniture can further reduce echo and cross-room noise.

Ready to Turn Down the Volume?

Whether you’re keeping street noise out of a nursery, blocking TV sound between rooms, or calming a home office, smart insulation is the most cost-effective first step. By pairing cavity fills with thoughtful air sealing and acoustic upgrades, you’ll hear the difference immediately.

To see what will work best in your home, explore our attic insulation installation and air sealing services, then get in touch. We’ll provide a clear, itemized plan to make quiet your new normal.

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