Mar 5, 2021 · IIC stands for Impact Insulation Class. This is the rating given to flooring assemblies and determines how well they mitigate impact noise (footfall mostly). As opposed to STC, IIC rates the flooring assembly as a whole, not just the material on its own. Determine Target IICs. The different parts of a flooring assembly can include:

Dec 20, 2022 · IIC (Impact Isolation Class) measures a floor assembly’s ability to absorb impact, structure-borne or vibration sound – like footsteps. It’s represented with an integer, or whole number. A larger number means more impact sound is being blocked.

Understanding STC, OITC, IIC, and Delta IIC (ΔIIC) can help you determine the best soundproofing solutions for your specific needs.

Learn underlayment sound definitions like IIC, STC, and Delta IIC to understand how underlayments reduce noise and improve sound control.

Mar 26, 2025 · What’s a Good STC or IIC Rating for Your Space? For homes, aim for STC 50+—it quiets traffic or voices; 60+ is studio-grade, nearly soundproof against daily noise. IIC 50+ works for apartments—muffling steps—while 65+ is luxury, turning floors into silent zones—balance cost against your sanity.

Aug 23, 2016 · IIC is used to determine the amount of impact noise isolation. As the STC rating, IIC tests measure sounds between 125 to 4,000 Hz but in this case it measures the amount of vibrations that travel through the floor/ceiling assembly.

Dec 8, 2022 · STC is airborne sound, which is a sound that can come from your upstairs neighbor blasting a TV or radio or talking very loudly at each other. However, most buildings already have decent STC performance on their own. The most common noise complaints will come from IIC, which stands for Impact Isolation Class.

STC stands for sound transmission class. This is the most common sound rating used in North America for determining airborne sound transmission loss between 125 Hz and 4,000 Hz. This range covers the majority of common noises we hear including speech, television, music, dogs barking, and other similar annoyances.

STC rating helps us measure how much sound is transmitted between rooms. And IIC rating helps determine the soundproofing between different floors of the building. All three rating systems are very important to creating a well-soundproofed building.

Feb 5, 2016 · Impact Insulation Class (IIC) Testing. Impact Insulation Class (IIC) is a rating commonly used to evaluate a floor/ceiling partitions ability to resist structure-borne impact sound transfer (i.e., walking, shuffling).