ICF STC Rating: Why Concrete Homes Are Quieter

When ICF homeowners are surveyed about their favorite features, "quiet" consistently ranks in the top three — alongside energy efficiency and durability. ICF walls block 50-75% more noise than standard wood frame construction.

Understanding STC Ratings

STC (Sound Transmission Class) measures how well a wall blocks airborne sound. Higher numbers = better sound blocking.

• STC 25-30: Normal speech easily heard through wall
• STC 35-40: Loud speech audible but not intelligible
• STC 45-50: Loud speech barely audible
• STC 50-55: Most sounds blocked (ICF range)
• STC 60+: Professional recording studio level

ICF vs. Wood Frame Sound Blocking

Standard Nudura ICF walls with a 6" concrete core achieve STC ratings of 50-55. For comparison:

• Standard 2x4 wood frame with drywall: STC 33-35
• 2x6 wood frame with insulation: STC 36-39
• Double-stud wood wall: STC 45-50
• ICF (6" core): STC 50-55

ICF achieves better sound blocking with a simpler wall assembly because of the mass and density of concrete combined with the decoupling effect of the foam insulation.

Real-World Benefits

ICF homeowners consistently report these quality-of-life improvements:

Highway & Traffic Noise

"We're 200 feet from I-35 and can't hear traffic at all. Guests are always amazed."

Airplane Noise

"We're under the flight path to Austin-Bergstrom. In our old house, we could hear every plane. In our ICF house, we forget we're near the airport."

Neighbor Noise

For multi-family or close-proximity homes, ICF party walls provide excellent sound isolation between units.

Storm Noise

"During storms, we can barely hear the wind and rain. It's almost eerie how quiet it stays inside."

Perfect for Work-From-Home

With remote work becoming permanent for many Texans, home offices need to be productive spaces. ICF provides:

• No traffic noise during video calls
• No lawn equipment interruptions
• Better focus and concentration
• Professional-quality audio for podcasts or recordings